KR> carbon monoxide poisoning
The "smoke in the plane" thread reminded me of Doug Steen's story. Some of y'all know Doug from the Gatherings and SNF/OSH. He flies the Cirrus and a Tailwind now, but earlier it was a V-tail Bonanza and a Luscombe. He was flying from somewhere like VA down to Deland FL in his Dragonfly (or Quickie, or whatever) at high altitude. Along the way, he developed an exhaust leak, that eventually knocked him unconscious. His plane ran fine and straight without him, until it ran out of fuel somewhere over central Florida. While he was still unconscious, the plane hit the ground at a survivable angle, but injured his legs substantially, which to this day gives him a slight limp. The funny thing is that if he'd had more fuel, the plane would have flown longer, and he probably would have died of CO poisoning. As it was, when the engine quit and the plane crashed, he eventually woke up, and survived it all. He's the only guy I know whose life was saved by a plane crash... -- Mark Langford ML at N56ML.com http://www.n56ml.com
KR> VW prop hub connection
Those FAA accident reports are quite sobering, pointing the finger almost entirely at engine problems, inadequately prepared pilots, or just lack of attention to detail (and then there's the stupidity). One that caught my attention (and doesn't fit any of the above descriptions) is this one regarding a departed propeller. > The FAA inspector reported that the propeller is attached to a > flange, which in turn is secured to the Volkswagen engine crankshaft > by means of a bolt and cotter pin. The pin was found sheared and the > bolt backed out. Evidence of full thread engagement at some time was > noted on the bolt. The inspector stated that 5.7 hours of ground run > and taxi tests had been completed by the pilot prior to this first > flight. > > Probable Cause The failure of the propeller attach bolt retaining > cotter pin, and the pilot/builder's inadequate preflight inspection > of the aircraft prior to the attempted flight. If this hub was anything like my GP hub setup, the determined cause is backwards...the hub slipped on the crank taper, and THEN the cotter pin sheared, not the other way around. That little cotter pin couldn't possibly keep the hub from spinning on the crank, although somebody might think that it would. That cotter pin is simply an indicator that the hub has slipped, and that the taper connection needs immediate attention. Why would the hub slip? It's as simple as an engine backfire. When I was having problems with my Compufire ignition just before Chino, I didn't have enough spark to start the engine when the starter was running, but when the ignition was switched off, the coil field would collapse and a spark would fire on some cylinder that was charged and ready to go, and spin the engine with a bang and a dramatic shock to the crank. The prop/hub mass makes it reluctant to move, so the hub slips on the crank, unscrews the bolt, and shears the cotter pin in the process. The cotter pin will shear right off with that kind of load applied to it. Next time the engine starts, the prop comes off, and if you're lucky, it lands on the ground nearby, rather than killing somebody or something. In my case, it just killed itself on the concrete...$400 down the drain, and killed the spinner as well. I think that bolt should have left-hand threads, be larger diameter, and be torqued higher than the manual calls for...like Revmaster does their prop hub connection. Yes, there is also a steel key between crank and hub, but the keyways are surprisingly shallow, the key is pretty thin, and it does not always offer enough resistance to keep the hub from simply "overriding" the key. The key is also not designed to prevent rotation...it's just there to keep your timing mark in the same place every time you rebuild the engine. And when you remove the hub (or it removes itself) and discover the key has fallen into the engine (because it was facing down when the hub was slid off), you get to tear the engine down to retrieve it! The moral of this story is be super careful not to misfire the engine, and if you do, take a look at that cotter pin and ensure that it's not twisted or sheared. Also, torque that bolt to the high end of the given range or higher, and secure it with Loctite 620 (although that still wasn't enough in my case). I'm not trying to start an AD here, but am advising those with this hub connection to pay particularly close attention to detail during installation. If you have a bunch of hours on it, it's probably going to take a lot of tons on the press to get it off, and would probably run without the bolt even installed! Contrast this hub connection to what you get on even a stock Corvair crank...six high-strength 3/8" fine-threaded bolts (formerly holding the flywheel on) that practically guarantee the hub isn't going to slip or come off the airplane, and removing six bolts and the hub is easily removed. It couldn't be much simpler or more trouble free... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> parachutes
Also, you're far more likely to roll it up in a ball during a landing, so why not airbags too? Mark Langford ML at N56ML.com http://www.n56ml.com
KR> parachutes
Regarding parachutes, it's worth mentioning that there's never been an inflight structural failure of a KR (the all-composite one at high speed at the Gathering doesn't count, in my mind), although there is a question of elevator bellcrank failure in one plane, but it's possible it was crash induced. There may be others, but no spar or fuselage failure that I know of. So given that record and the many thousands of KR hours logged, what are the chances that you're going to have to go down somewhere so inhospitable that you can do some semblance of a landing somewhere? Even if it's in the tree tops, you'll likely survive it. So assuming you are still in control of a plane that's capable of gliding, I'd just stall it in the tree tops somewhere. John Schaffer did that in a flat spin from 8000', and survived. And how much time do you spend over that kind of terrain in Missouri anyway? Your chances are looking better already! Jeff Scott probably doesn't like what he sees out the window 75% of the time, but he doesn't wear a parachute. Jumping out of a spinning or otherwise disabled plane is not without its risks as well...perhaps higher than sticking with the plane to put it on the ground somewhere. You could get whacked in the head by the horizontal stabilizer, or your parachute might be a streamer, etc. And what if your plane crashes into a house and kills a family eating lunch? That'd be bad. I guess what I'm trying to say is if you are so concerned about a structural or control failure, you should probably start thinking twin engines and lot of other redundancy. Statistics are on your side though...if your plane goes down, it'll likely be a fuel problem or a broken crankshaft, and then you simply land in a field or on a road. At least that way you still have a plane that you can rebuild or scavenge for parts, or just maybe, it won't have a scratch on it! No need to carry 20 pounds around for years expecting it to pay off someday, when it likely won't. I have about 1400 hours of KR time, and I've had plenty of engine problems, and zero structural problems. With the plane 20 pounds lighter, and the comfort of not being packed into my seat with a parachute, I've had some pretty smooth and enjoyable flying so far. And yes, I do know that the second engine is just there to get you to the scene of the crash... -- Mark Langford ML at N56ML.com http://www.n56ml.com
KR> MGL and the new instrument panel
Mike Sylvester wrote: >>About the MGL. I have a friend that is building a Bearhawk LSA, He blows me away with his knowledge of electronics. He's having issues with excessive RF. You can't get any radio within 5 feet of the unit without static taking over, even a handheld. After trying all suggestions from the factory, It's got to be shipped back. Your results may vary.<< Don't get me started on the MGL iEFIS...it won't be pretty! I'll have to write a web page on that, and it'll take months. Suffice it to say that mine will change the FM radio in my hangar from perfect reception of a local station to complete "white noise" as soon as I flip the iEFIS on, and that's running off a backup battery with nothing else in the circuit! And they think I have bad grounds, alternator, ignition, whatever it takes...but that's not what my oscilloscope says, and the FM radio agrees! And it goes WY deeper than RFI, trust me. More on that as the web page progresses. For that matter, I just got my iFly 720 back in the mail for the second time in two years with maybe 250 hours of use on it. I "bricked" it doing a routine software update just before the Chino Gathering, and the touch screen went south recently, requiring a new one for $120. The software is superb and vastly intuitive, but the hardware has reliability issues. The lack of an internal battery is unforgivable. Compare the old iPad2, which is pretty robust (it stood up to many years of use by my teenage daughter before I inherited it), which has bluetooth and wifi built in and is half as thick with a screen twice as big, has a battery that lasts for many hours (for years), and can be bought used off of ebay for under $100...and it runs the iFly software perfectly.Add a Stratus ADS-b coupled to it, and my old EIS engine monitor, a Trutrak autopilot, an altimeter and airspeed steam gauge, and I'll be quite happy. That's my next instrument panel. See enclosed image... Mark Langford ML at N56ML.com http://www.n56ml.com > -- next part -- A non-text attachment was scrubbed... Name: panel2.jpg Type: image/jpeg Size: 77998 bytes Desc: not available URL: <http://list.krnet.org/mailman/private/krnet_list.krnet.org/attachments/20160507/39f9c286/attachment.jpg>
KR> off-airport
Larry Flesner wrote: >>The way Marty pushed his little KR I'm guessing he had more near death experiences than Langford with his four off airport landings. :-)<< I'm thinking that's only three for me. And if there had been a grass strip where the sectional (and my EFIS) said it was, it would only be two. Instead, 90% of it was 6' tall corn, having been sold to a farmer two years prior... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Corvair hydraulic lifters
Mike Stirewalt wrote: > Those hydraulic lifters you mention Mark . . . they sure work fine > in cars and everything else but Steve Bennett told me he took > hydraulic lifters out of the original HAP 1835 that Ken Cottle put in > my plane to start with. Steve said they were taking too long to pump > up and were spalling the cam lobes. I don't know of any issues with the hydraulic lifters on Corvairs. Due to crankshaft issues (which I'm convinced are solved with the advent of the NEW 4340 crankshaft), I've had the 3100cc engine apart twice in 551 hours, and the lifters have shown very little wear, and the 2700 has never been apart after 457 hours. I've never heard the valves make any noise on startup on either engine, including the very first startup, thanks to the pre-oiling procedure I mentioned earlier this week, which pumps them up nicely. After assembly, you can glue the valve covers on and they won't need to come back off until rebuild time. GM knows how to do hydraulic lifters. On the other hand, my 2180 VW engine was spalling one of the solid lifters when I tore it apart after the sucked valve incident. And yes, both lifters and cam came from the same manufacturer (Eagle), and they were properly lubed with moly cam lube at assembly. Mark Langford ML at N56ML.com http://www.n56ml.com
KR> oil priming a VW type 1 engine vs the Corvair
Speaking of priming, my experience with getting a Type 1 VW engine to prime on a taildragger has been has been pretty miserable! First step is to coat the oil pump gears at assembly to make a tight enough seal to hopefully suck oil out of the sump, and that sump tube is pretty long and large diameter. I also just Lubriplate 105 (Motor Assembly Lube), mainly because it comes in a large tube with a nozzle on it that makes it easy to squirt between the gears. Fill the crankcase with oil. Next step on a taildragger is to get the tail up, preferably over center so the nose is actually lower than the tail. This is easily done with a saw horse, and I have a sawhorse with foam and carpet on it that's custom made for the KR2 (thanks to Jim Hill). By moving it fore and aft under aft fuselage taper, the angle can be varied. [I threw this in for Larry F, to get the engineering complication out of the way]. So, best to have the nose down, but not low enough to kill the prop during rotation. I then remove the oil pressure sending unit (same location as the stock oil pressure switch on the Beetle, adjacent to the distributor) and pump that passage full of oil with an oil can, some plastic tubing, and an 1/8" NPT barbed fitting. This takes a lot more pumping and filling than you might think. Rotate the prop backwards a little when you think you've got it full, to see if it will hold more, and refill if necessary. Remove the NPT fitting and install a mechanical gauge (you can buy a cheap one for ~$20 at the parts store) so you can watch it and tell when the engine is primed. Once primed, install plugs, leave the gauge there (as a second opinion to the whatever electronic gauge you have), and fire it up, following the break-in procedure. Contrast this process with the Corvair, which on a taildragger, has the oil pump at the back of the engine, down low. If the crankcase is already filled with oil, the oil system is already primed, as the whole works is submerged in oil! You could fire it up and have oil to the bearings in a few seconds, but you still need to pump oil through the system though, to fill any external filter and to pump up the hydraulic lifters so it'll run quiet immediately on startup. This is done with an old distributor housing with the drive gear removed from the end. Insert the old distributor, rotating to engage the tang in the oil pump gear, put a drill on the top of the distributor (where the rotor goes) and spin until you hear oil squishing out between the bearings and other places. Rotate the prop a few degrees, and repeat a few times. You are now ready to fire the engine up! The old distributor drive trick doesn't work on the VW though...you'll just tear the cam gear teeth up instead. So many advantages to the Corvair... -- Mark Langford ML at N56ML.com http://www.n56ml.com
KR> VW cylinder heads
Tommy Waymack wrote: > Pulled my VW heads with low compression. Discovered crack between the >valve > seats at the shortest point. My question is, does anyone repair them?Or are > they junk? I know this is a common problem, but it's my first time I wrote this out as an email, but I've been meaning to do a webpage regarding the VW, and decided to make this a start on it. See http://www.n56ml.com/n891jf/vw/ for the rather poor experience with VW heads on the nose of a KR2... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> 94x82 vs 92x82
Owen wrote: >>Is there any downside to moving to the 94mm cylinders vs 92mm's? My son's project currently has the 92x82 for 2180cc. I can move to 94x82 for about the same cost as sticking with 92x82 in an upcoming rebuild.<< Several of us are running 94mm cylinders on the Corvair with no problems at all. You'll probably go through at least two sets of VW heads before you need to touch the pistons/cylinders. They are well proven. I put 550 hours on a set in N56ML and they still look great and have great compression. I've built two GPASC engines (and torn them both down several times for hub issues), and if I were going to build another VW, I'd use the Revmaster crank and prop hub setup instead. Mark Langford ML at N56ML.com http://www.n56ml.com
KR> KR Engine Cowling
Pete Klapp wrote: >>My question for Mark and fellow netters is where to purchase carbon fiber cloth other than Aircraft Spruce as they are pretty pricey. Also need to know which weave is best to use.<< The last CF I bought (and that was a long time ago) was from http://www.avtcomposites.com/cgi-bin/commerce.cgi?search=action <http://www.avtcomposites.com/cgi-bin/commerce.cgi?search=action&category=09 00> &category=0900 . They had pretty decent prices then, but I'm not sure how they stack up these days. I used 282 3k, which is 5.9 ounce, for my wing covering, since it's light and it was overkill for wing skins anyway. I bought enough to do the cowling, which is 2 layers all the way around, except I put an X shaped reinforcement across the top because that surface is largely flat and unsupported (until I built plenums under it). N56ML's cowling is admittedly flimsy, but weighs 4 pounds total, including the hinge pin attachment. Still, it's strong enough that I took off once with one whole horizontal hinge pin missing once (it was installed, but I missed the mating hinge pin and didn't notice). On climbout I noticed the right side of the cowling was sticking up about 8", and it simply stayed lifted like that until I landed and fixed it. That was a heart stopper. See http://www.sollercomposites.com/fabricchoice.html for a description of weave styles. Twill is the ticket for compound curves, but "plain" 282 worked fine for me. I guess it would be better for the inlet areas with their tight curves, but mine worked out OK. Mark Langford ML at N56ML.com
KR> KR2 landing video
You guys are a tough crowd! This may look like a flat high speed landing, but notice that I chopped the throttle to idle way before turning final. All the noise you hear is wind noise, not engine noise.? The prop is probably turning 1100 rpm, but the wind is helping it spin, since it's normally idling at about 750 statically. I was gliding all the way in, and testing has shown that best glide speed (around 85-90 mph) results in a 600fpm descent rate, or 10' per second. That's not to say that I couldn't zoom in and touch down, but not on this runway I can't. This was a slightly hot landing though, because I have been able to get on the brakes hard and stop at the halfway point a few times. My normal landing is to do about 120 mph on downwind, fairly close to the runway, then chop the throttle as I get to the 45 degree angle off the approach end, then glide in the whole way. This is to simulate an engine out landing, as I've learned that it's a real possibility! I can't slip the KR2 nearly as steeply as I could the KR2S because of the small rudder, and I guess I've gotten so good as estimating the end of the runway that I rarely have to do that to get pretty close to the end. And maybe it's just that I still lack the confidence that I had in N56ML. I almost exclusively did three point "carrier landings" with N56ML at my home airport (M38), but I could see over the nose a lot better, thanks to the larger and taller canopy, and ground handling is so much better than with this KR2. The short-coupling of the KR2 extends into the tailwheel distance from the mains, so it's considerably more twitchy than a KR2S when landing. So I land just fast enough to see over the cowling a bit better, and to have better, smoother, and more predictable control using the rudder than the tailwheel. Another factor is the bad geometry of the rudder/brake pedals on this plane...I have to be very careful to lower my feet so I push on the bottom of the pedals to prevent braking at the same time. I'd fix this, but it's a nightmare to do anything under the panel, and I can only reach those pedals with my fingertips, and with only one hand, so that's not happening. Another reason to make your front deck removable! Although it looks like my canopy is cracked, that was just a big bug I hit on takeoff. I always clean the canopy before takeoff, and this video was after four touch and goes during one of the first warmish days of April, so the bugs were out flying too. Something else about the video is that it sounds like the engine is missing when I turned onto my taxiway, but that's just wind noise freaking out the camera mic. That engine never skips a beat...so far. Mike Sylvester...you are welcome to drop in or fly over any time. You'll be in good company if you beg off of landing...Pesak did that a few weeks ago. As for the windsock, Larry, there may have been a slight tailwind, but it beats staring into the sun on landing. The blinding sun is bad enough, especially when I'm already having trouble seeing the runway, but that strobe stuff just makes me crazy, so I avoid it. Besides, my hangar's at the other end of the runway! Since I'm a apparently a glutton for punishment, how about a touch and go video at a "normal" size runway (KFYM, Fayetteville, TN)? This was a bumpy day, with a little crosswind. See https://www.youtube.com/watch?v=oAjMsWMexjQ&feature=youtu.be . Mark Langford ML at N56ML.com http://www.n56ml.com
KR> KR2 landing video
NetHeads, I finally got around to mounting a Sony SteadyCam video camera in the plane, and have been shooting MP4s of a few takeoffs and landings. I posted one to youtube last night, at https://youtu.be/y2PTrOBGAVU , if you want to take a look. This is my home airport, only 40' wide and 2600' long, and the taxiway to the hangar is only 12'. Note that I was on the brakes and the rollout at the end was still pretty short. Visibility for the camera is considerably better than for me, as it is mounted higher than my eyeballs. This looks like a fast landing, but it's just the wide angle view that does that. Actual touchdown was in the upper fifties. Obviously these are wheel landings, as the canopy and cowling arrangement leaves no hope of seeing where you're going otherwise, and the runway is too narrow to use peripheral vision. More to come later... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Tail Wheel bearings
I also recommend the 20 degree Aviation Products tailwheel, as I've had zero problems with mine other than wheel bearings. For that reason, I would buy the tailwheel assembly directly from the source, Aviation Products, at (805) 646-6042, rather than AS&S. It is less expensive than from AS&S, and you know for a fact that you are getting high quality sealed (and lubricated) wheel bearings with it. If that sounds ridiculous, please see about a quarter of the way down http://www.n56ml.com/kgear.html , where I was sold dry, ungreased (and ungreaseable) bearings by AS&S, with no apologies. I like to spread this word whenever possible. There's no point in feeding the bears, and rewarding them for knowingly screwing builders! And no, the above has nothing to do with springs on the tailwheel cables, but as you can see from the photo on the website, I don't have any springs either, just a little bit of slack to that they don't limit rudder travel at full stop. Troy Petteway recommended this setup, and it works fine on both N56ML and N891JF. If you are on a budget and like to make things yourself, the tailwheel setup shown in the KR2 plans works fine, weighs less, and is at least as aerodynamic as about anything else you could think of. Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Gap Seals
Jeff Scott wrote: > I tested both with and without the gap > seals. With several climbs to altitude and several speed runs. I > found no discernible difference in the performance numbers of my > aircraft between flying with and without the gap seals. I think the difference may be that you can follow the plans and end up with a big gap at the lower front edge of the aileron, or you can take some care and design the nose of the aileron so that it comes close to sealing itself. I'll throw out that perhaps Troy's RAF48 "per-plans" ailerons may have had a big gap at the bottom during straight-ahead flight, whereas both mine (N56ML) and yours likely seal better at the nose and therefore do a better job of sealing themselves, so gap seals don't help in our case. I can't vouch for Troy's experience, but can verify my own with the AS5048 wing and Frise aileronsno discernible difference with gap seals installed. Just FYI, N891JF came with gap seals installed, and I haven't noticed a lot of difficulty in making turns. But I also haven't experienced a stellar climb rate either. Maybe I need to do some testing, rip them off, and do some more testing. I'll have to find a fish scale that measures in grams though, instead of ounces of force. What I really need is a Corvair hanging off the nose of this thing! While we're on the subject of gap seals, I'll throw this out. If you're ever tempted to fly around the patch without the gap seals between stub wing and outer wing installed, be prepared for a dramatically lowered climb rate. And if you do it with only one missing and the other installed, be prepared for a serious roll tendency! How do I know this? Experimentation... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Adverse Yaw
And since this message was titled "adverse yaw", it's worth mentioning that most KRs, due to the differential aileron bellcranks shown in the plans, eliminate adverse yaw. Takeoffs, climbs, and landings are the only time that a slight amount of rudder is needed. The rest of the time the plane keeps the ball centered all by itself. As Larry Flesner says, "as long as I keep my feet off the pedals, the ball stays centered"... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Adverse Yaw
Owen wrote: > However, I also read an article about how important gap seals are for > increasing climb performance. See http://www.n56ml.com/troy/ for more on gap seals. Just looking at that big honkin' gap that you get when you build the wings per the plans, you can guess that there's an improvement in performance with gap seals. I built my wings with a Frise aileron, and with gap seals on that, I saw no benefit at all to the seals, mainly because the gap seals itself if you do it right. See http://www.n56ml.com/owings.html for more on that (near the bottom). Some folks would think that life is too short to spend this kind of effort on the ailerons, but I thought it was pretty simple and made a lot of sense. I will do my next one the same way, but will likely use a piano hinge at the top for simplicity and drag reductions (eliminating those external hinges from the airstream). Mark Langford ML at N56ML.com http://www.n56ml.com
KR> weight and balance
Gary wrote: > From my plans, the CG is 15% to 40% of the wing chord. That was the old > wing. Is it the same with to AS5048 wing? I don't ever remember seeing that number before. Is that for a KR1, or just an early set of plans? My plans also say 15%-35%, and that's the range that extends too far aft to be safe (according to an analysis by Richard Mole and also experience by pilots). The AS50xx series airfoils are designed to have a similar lift coefficient and range (15%-35%) as the RAF 48 (minus those aft two inches). Mark Langford ML at N56ML.com http://www.n56ml.com
KR> C.G location, Engine centerline
Larry wrote: > Each time the engine moves forward > so does the distance of your new "arm" for calculating the new > moments (weight on the three scales). Sure, it's a sum of moments either way. But why would you want to change not only the changed weights, but every other distance in the spreadsheet (or worse, your W&B sheet)? Now THAT's some bothersome math, adding whatever your new arm is to all those moment arms, rather than just the moment arm of the engine alone. That sounds like an increased opportunity for error, at least it would be for me. I know Larry knows this...just pointing it out... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> C.G location, Engine centerline
Pete Klapp wrote: > The temporary engine mount I made allows me to move the engine about five > inches fwd and aft. I'm using the tip of the spinner as my ref datum so > each time I move the engine fwd so moves the datum and I'm not sure if > that is correct. The datum needs to stay in the same place while you slide the engine around, so the firewall is a good place. I used the backside of the prop hub, but that was AFTER the engine location had been determined. I don't think the spinner is a good place for the datum, since spinners "come and go"... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> C.G location, Engine centerline
Pete Klapp wrote: > I have done calculations with pilot plus 1/2 fuel and it falls at 2" into > the RR cg range, and pilot & passenger plus 3/4 fuel and cg falls within > 6" preferred cg range, the later coming in right at the aft edge of the > preferred range. I'm thinking that I would like set the engine such that > with me and 1/2 fuel that the cg falls right at the fwd cg limit.< N891JF is right at the forward limit with pilot and full fuel, and I can tell you that I need a lot of UP trim to keep the nose up, but it's a small trim tab and I still have plenty of travel left, so it does work. Forward is certainly better than too far aft, and even though yours has a nosewheel, I wouldn't expect any problems being able to rotate the nose up on takeoff. It's easy enough to move some things aft if needed later, and it's better to start with max stability, rather than min. > Next question: The horizontal engine centerline with the temporary engine > mount is 2.5" below the top of the upper longerons. I'd like to drop the > centerline a little more, 1/2 to 3/4", for better clearance for engine > cowling and cooling plenum. Anyone see a problem with that.< My CG is 2.375" below the longerons on N56ML, and it's not a problem at all in any respect with my plane. Mark Langford ML at N56ML.com website at http://www.N56ML.com
KR> Fwd: Re: source of 65 HP aircraft engines and parts, and some airplanes for sale
KRnetHeads, Doug Steen would like to notify folks that if you're looking for an O-145 engine (65HP Lycoming) or parts for one, he knows where to find them. One of his airpark neighbors had a large cache of these and recently died, leaving his wife with a shop full of engines and parts. See http://www.krnet.org/misc/O145/ for photos and contact info (at the bottom). Mark Langford ML at N56ML.com http://www.n56ml.com
KR> something else to worry about...
On the way back from flying down to my father's farm last week, I was almost home at 8500' when I suddenly felt like I'd been stung in the butt, but it just kept on burning. It was bad enough that I immediately popped the seat belt and started trying to figure out what was going on, especially after I started smelling an electrical fire! My first thought was "I don't smoke E-cigarettes, but this seems eerily familiar". Once off the seat, I found the cause...the "Lightning" charge cord for my iPhone 6, which I had used to charge my phone on the way down, was smoking hot! Apparently I was sitting on the edge of the passenger seat belt, and the end of the cord was sandwiched between the buckle and my butt, shorting it out and eventually blowing up the little voltage regulator that's embedded in the iPhone end, after it got hot enough to get my attention!. Something else to worry about... NOT sent from my iPhone! -- Mark Langford ML at N56ML.com http://www.n56ml.com
KR> LSA Operation
Lee Parker wrote: > I had a friend that spent a year in jail. Was there something egregious in the circumstances, like somebody was killed or injured? I'd be surprised if you would get a year as the result of a ramp check when there were no extenuating circumstances. Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Wednesday KR2 flight
KRnetHeads, Here's a quick report on a flight I made down to my father's grass strip yesterday, which is 80'x3600', and not a bad place to fly out of. I'm sure I didn't use half of it, either landing or taking off. There are trees on one end, and it's uphill toward the trees, so it's pretty much a one-way strip that works quite well. On the trip down I was burning 3.4 gph while doing 145mph True AirSpeed at 7500' on a nearly "standard" day. That's 43mpg, and getting there pretty quick. TAS is irrespective of head or tailwind, so this is a repeatable result. The trip was completely uneventful otherwise, except the hazy skies allowed me to wander all over the place. I need an autopilot to keep me on course and at altitude! See enclosed photo for a nice view of the grass strip, with N891JF ready to go. The strip is situated between three lakes. See http://www.n56ml.com/flights/jan2006farm/ for a better view of that. -- Mark Langford ML at N56ML.com http://www.n56ml.com -- next part -- A non-text attachment was scrubbed... Name: 160316_017m.jpg Type: image/jpeg Size: 125278 bytes Desc: not available URL: <http://list.krnet.org/mailman/private/krnet_list.krnet.org/attachments/20160317/00083c39/attachment.jpg>
KR> Wing Extensions
Steve Goosic wrote: >>Since my wings are already built (RAF48), do I extend both wing spars or is it possible to add additional foam to the existing wing end and shape to form? Also, how much further do the wings need to be extended?<< See http://www.n56ml.com/900hour/ for how I extended my KR2S wings 14". Also, below is something I posted to KRnet at about the same timeregarding the same question. I fished this out of the archive, at http://tugantek.com/archmailv2-kr/search. There's plenty more on this subject there as well, but below is a pretty good summary. Bottom line is that the plane has to be very light (like same KR2 gross weight) to get away with adding only a few inches to each wing. Subject: Re: KR> longer wing panels, etc. From: Mark Langford List-Post: krnet@list.krnet.org Date: Sat Jul 10 19:37:54 MDT 2010 Tom Garner wrote: > My hope is that some young bright engineer will come up with a wing design > to make KR2-s comply with LSA requirements. Outer wing panels of > course, not a total rebuild. That's not as difficult as it sounds. You almost don't need any math to get there. If you believe the stall speed numbers published for the KR2, about all you have to do is increase wing area by the same percentage you want to drop the stall speed to get under LSA requirements. Of course your gross weight may be higher, so you've got to do that twice. And if the published numbers are optimistic, you might build in another fudge factor. And then there's just spending an evening doing homework by reading stuff like John Roncz's ""Designing Your Homebuilt" from Feb 1990 Sport Aviation magazine or "Sizing Your Wings", or something similar. His spreadsheets are floating around on the web also, which make it even easier. Coefficient of lift is given in info on one of the links from the AS504x webpage at http://www.krnet.org/as504x/ . There are several variables involved in upsizing the wings for YOUR airplane, so rather than have somebody do the work for you, I'd recommend doing it yourself for your airplane. There's a basic equation the FAA might use to give your design a "reasonable test" for stall speed, and all you have to do is meet that (you'll find it in the Roncz works). And I'd name the airplane something other than a KR also, because the KR2 and KR2S already have "hard" stall speed numbers published by the manufacturer, so to keep from muddying the water, call your plane something other than a KR. But the bottom line is that you could almost guess that an extra few inches longer than the Diehl wing would get you into LSA territory. You just need to be able to whip out that calculation when the FAA guy asks for it. But you might want to use the 18% AS5048 airfoil to get deeper and therefore stronger spars in the deal. And if the plane's already been registered as an experimental, it's too late to call it an LSA, although I believe it can still be flown as an LSA. The other part of that is the max speed, so you'd need a small engine or a fine-pitched prop to keep from exceeding it. Gotta get back to the hangar for another round with the vinyl ester fuel tank... _ Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Alternative Engines
Joe Nunley wrote: >I am in search of an affordable engine, as we all are. My dream is to have an O200 because I would like to have 100HP, not much luck finding one that I can afford. What experience do you have with other engines?< Regarding the Corvair, have you contacted any local Corvair clubs, visited, spoken at their monthly meeting that you need an engine to power an airplane? That's what I did, and that's where my first engine came from. Have you joined the CorvAircraft email list and asked there? Also, I don't know if he still does this, but Larry Hudson used to sell core Corvair engines and would deliver them to Corvair Colleges. I think Joe Horton either sold or offered a Corvair just a few weeks ago. Given my checkered record with Corvair crankshafts, it may be a surprise that I still think a Corvair is a viable aircraft engine, IF it has a NEW 4340 crankshaft from Sport Performance Aviation in it (but they aren't cheap!). Sure...most reground stock crankshafts seem to last as long as a fifth bearing is installed, mine being the notable exception so far. The rest of that engine is just about trouble free. They run a lot cooler than a Type 1 VW due to having more fin area, have very few valve issues thanks to self adjusting hydraulic valves, and you only adjust the valves one time, on the workbench, for the life of the engine. And the big payoff is the safety of six cylinders and gobs more power to get altitude quickly for a safer climbout. Yes, I'm still a big fan of the Corvair. Having said that, with the money you'll put into a Corvair, or even a new VW, you could spend a little more and rebuild an O-200 and have a very reliable engine as well. If reliability is your ultimate goal, you should keep beating the bushes for an inexpensive O-200. If they are simply out of range, the Corvair is a good runner-up, and statistically, a reground stock crank is a pretty good bet, given that only one has failed with a fifth bearing, as far as I know...mine! When you factor in a torn up airplane, the playing field is more-than leveled when you start with an O-200... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Search for an Ellision Carb Heat Box
Rene French wrote: > Does anyone have an Ellison TBI Carb Heat Box in their extra box of goodies that is for sale? -- I don't have one for sale, but I can show you exactly how to build one yourself, at http://www.n56ml.com/corvair/airbox/ . I think this would quality as "per the Ellison drawings", as far as entrance criteria for the air goes. It works great, as does the Ellison... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Can this plane be fixed?
Mike Stirewalt wrote: > The whole top half has come apart from the bottom. It appears to > have just fallen off. It's just lying there on the ground next to the > plane. Tornado? Vandalism? A real mystery. Yep, an experiment gone terribly right. I hear that aft deck was tested to 245 mph, despite doubts that a thin piano hinge and some number 4 wood screws would hold it "at any speed". Maybe this is what happened when it landed after that flight... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> KitPlanes magazine
KRnetHeads, If you aren't a subscriber to KitPlanes magazine, you are really missing out on a great resource. It got a little cheezy over the years with respect to covering way more off the shelf kits, rather than scratch built airplanes like we are building. But when Paul Dye took over as editor, it immediately hung a hard "technical" turn, and is now jam-packed with deep, meaty articles that cover both basics and the nitty gritty of a subject, written by very knowledgeable authors. I'm way behind in my reading, but intake systems, ignition, exhaust, riveting, metal forming...all kinds of stuff. And of course Baranaby Wainfan is still writing great stuff on drag reduction and things of particular interest to us, like elevator and rudder design, with and without horns. I'm looking forward now to Jim Weir's "how to" on making your own LED nav light system for dirt-cheap, using only two LEDs per wing tip. That's coming soon also, and it's something I'm way overdue on. No commission or kickback here...I just trying to spread the word of this great resource! -- Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Archives
Steve Stardusterone wrote: >> I haven't been able to access the archives for a couple of days. Anyone else having problems? HelpI'm having serious withdrawal symptoms!<< I have emailed Tom (the guy that runs the archive) to take a look at it. This service has been down for several weeks at a time lately, so it's probably time we considered doing this differently, or at least compensating him for his effort. I've asked for his Paypal address so we can throw some money at him to make this at least partially worth his time and effort. He spent a lot of time writing the code to parse through all our old emails and building the front-end to search it. He volunteered to do this as a service (he's an airplane guy too) to keep the thing alive for us, but it's asking a lot from him to do this forever for free. There is another way to see KRnet email, through the standard stuff that comes with the list. It's not as slick and useful, but if simply checking email in chronological order, it works. It's at http://list.krnet.org/mailman/private/krnet_list.krnet.org/ using your email address and password. If you don't know your password, go back to the first day of the month and look at the email you got from the list, which is a password reminder, if nothing else. Meanwhile, I'll work the viability of the archive... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Tail Addition
Joe Nunley wrote: >> How much carbon fiber is enough? I built a 6 inch extension to my tail surface the way that Mark describe below. When I attach the new addition to the airplane I will t88 glue it to the tail and cover in carbon fiber. I want o overlap the old and new with carbon fiber. How far do I want to overlap? << I would have built the extension in place, as a piece of foam glued to the end, shaped using the existing airfoil, and then carbon-fibered in place, overlapping the existing stabilizer (after sanding to expose raw fiberglass) by something like 3"-4". T-88 isn't the first epoxy I'd have thought of for that job (the way I describe above), but given that it's already built, T-88 should work fine, as its thickness would help ensure all surfaces are in good contact. Rough it all up to ensure lots of "tooth", of course. Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Stef's Progress.
Stef wrote: > I did a update at our website. Hope that 2017 is our year for the first flight. That is a positively awesome carbon fiber Dragonfly canopy flange, and the whole installation is flawless. Excellent job of documenting it on your webpage also. Thanks for helping to show others how it's done. Anybody know who's selling Dragonfly canopies now? I know Todd sells them but aren't they "blown" rather than molded? Although I may settle for one of Todd's, I like the shape of the molded ones better. Mark Langford ML at N56ML.com http://www.n56ml.com
KR> saturday flight
Joe Nunley wrote: > Hazel green is a beautiful airport!!!I would like to visit there some day. I think it's the high quality of the picture that makes it look so good. The same guy that took the picture also keeps the runway lights and beacon working, the water out of the fuel tank, and spent last Saturday putting up a new windsock and patching the roof of the clubhouse. A very dedicated guy, apparently with lots of spare time... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> saturday flight
Gotta show the rest of you what we're talking about. See http://www.hazelgreenflyers.com/ for a few pictures, and a shot of the approach from the "bad direction", runway 25, near the bottom of the webpage. With a 40' wide runway, maybe some folks can appreciate the delicacy of landing a taildragger KR2 on this thing, especially since over-the-nose visibility is lacking, and visibility out of the bubble canopy is not so great. Having said that, I once landed my KR2S on a 16' wide "runway" in Mississippi. The KR2S is far more stable on the ground though, and has much better visibility with the Dragonfly canopy. Mark Langford ML at N56ML.com http://www.n56ml.com
KR> KR2 for sale
Jim Sellars wrote:
> Can you help me with accessing the postings on the KRnet? Rand
> Robinson facebook page?
Postings for airplanes for sale are simply emails to the list. People
ask, and others volunteer their planes for sale. Old KR2 projects are
out there and relatively cheap, but even with flying KR2s, quality is
often an issue. A flying KR2S is rare indeed. As was mentioned, Josh
Choitz has one, and I'm sure it's a nice one, but the link that
KRnet.org points to has disappeared ("frozen", it says).
I don't think Rand Robinson has a Facebook page (they barely had a web
page), but I believe it was mentioned that Josh Choitz was advertising
his KR2S on HIS Facebook page. Not being a Facebook guy, I couldn't
tell you how to get there, but it appears you have to have an
account...which is why I'm not a Facebook guy. Perhaps somebody on
KRnet could inquire for you.
Mark Langford
ML at N56ML.com
http://www.n56ml.com
KR> Saturday flight
Robert Pesak wrote: > Nice flight to Huntsville executive airport where Mark picked me up and drove to a great lunch at a local buffet.Thanks Mark. What Robert forgot to mention is that he flew over Hazel Green Airport (M38) and wasn't convinced it was even big enough to be an airport, opting for KMDQ instead! My brother's flown right over it several times, rarely able to find it. I'll have to confess to missing it a few time myself, despite the GPS telling me it's right there. It was a good get-together, and that is one very awesome KR2S... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Random thoughts about techknowlegy in an airplane
Joe Horton wrote:
>> Besides the thoughts of being behind the information curve I have
these fears of the issues that Mark L. is going through now and that is
losing the entire glass panel to some malfunction. <<
Yep, my iEFIS failed to come to life when I turned it on to return home
from a flight to my father's farm a few weeks ago, despite having power
and backup power as well. Consider being 250 miles from home, and
suddenly you have no engine info, such as RPM, oil pressure, oil temp,
CHTs, EGTs, barometric altitude or airspeed, transponder encoder, or
fuel consumption or level. I still had the iFLY 720 GPS and Foreflight
on the iPhone (if I needed it), but flying back home with no engine info
was a sobering thought, not to mention issues with several FARs, I'm
sure. A few days later it was just fine, so now I have an intermittent
problem that's waiting to bite me again.
And yes, I too have designed a new panel, using an iPad, iFLY 720, GRT
EIS ("old reliable"), ECO autopilot, and 3.125" altimeter and airspeed
indicator. I don't like having all my eggs in one flaky basket...
Mark Langford
ML at N56ML.com
http://www.n56ml.com
KR> wing attach fittings.
Brian Kraut wrote: > The main spar fittings are exactly the same for both the 2 and the > 2S. On the aft spar of the 2 the fittings should all the same, but on > the 2S the spar cants forward a few degrees some of the aft fittings > are a bit longer with a slight difference in spacing from the attach > bolt hole to the holes that go through the spar. They also have a > slight bend to them. I wasn't brave enough to say it without checking, but they are different. The KR2 had eight straight ones for the center aft spar, and eight for the outer aft spars that had the three degree bend, which gave the spars three degrees of forward sweep. The lengths have to be slightly different for the bolts to line up (through the spar). They are labeled in the KR2 notebook as numbers 2,3 and 4. Not sure why they aren't named 1, 2 and 3. Maybe the mains are "number 1", but the drawing isn't labeled as such. Go figure. The KR2S uses only two different aft fittings, eight of each. They all have the three degree bend, which yields 6 degrees of sweep for the KR2S aft spar, which gives it that more tapered look, and essentially helps to improve the MAC forward slightly, improving stability (slightly). To make this work though, eight fittings are longer than the other eight, so the bolt holes will line up (through the spar). I have them laid out on the bench with a straight edge against them, so I'm not guessing...and this does verify what I was thinking, given that Trailing Edge Technologies made a number of these, and I still have a set (for my next plane)... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Wing Attach Fitting questions
And I should mention that there are gobs of extra material on the main WAFs, so oversize bolts will work fine. The aft WAFs are far tighter, and that probably won't work there. Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Wing Attach Fitting questions
Dave Acklam wrote: > My mismatch is at the 'big' central bolt-hole where the top wing WAFs > attach to the top fuselage WAFs My bad...I apparently missed that detail. Then yes, I'd just make a new set of WAFs also. Although you can stress relieve 4130 after welding with a torch, to be sure it's as good as new 4130 plate, you need a "certified" welder, checked for incomplete penetration with radiographic inspection. New holes in new material is the way I'd do probably do it. It's a lot easier and cheaper. But just to throw another curve ball, given the amount of "extra" material around those holes, if the next larger diameter bolt would work, there's always match drilling to use the next size larger bolt, or even two sizes. Now that I think about it, that's exactly what I'd do if it were mine. Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Wing Attach Fitting questions
Dave Acklam wrote: > 1) What is the key force or mechanisim providing strength to the WAF joint? > Is it the clamping pressure imparted by the bolts? The shaft of the bolt > itself? > > 2) Is there a preferred method to 'adjust' a set of wing fittings that > were drilled wrong? Would welding up the hole & re-drilling work? Bushings? > Just make a new set? The accepted method to this (and you are certainly not the first) is to epoxy wooden dowels into the previous holes and redrill to fit the new fittings. Soak both hole and dowel in T-88 (or other similar) epoxy first. The main mechanism for how the WAFs work is through shear, in the case of the bolt-to-WAF joint, but the bolt-to-wood interface is through compression of the bolt against the hole in the wood. Regardless of where the WAF is, the bolt is only capable of pushing against the hole in the wood...not so good at pulling on a hole, so compression is what makes the bolts work in the wood. Given that, the dowel method makes perfect sense, and how it's been done in the past. It's all well documented in the old newsletters at http://www.krnet.org/newsletter/ . Another thing to realize is that when the plane is flying with positive G's (almost always), the upper spar cap is in compression, and the lower cap is in tension. That's why the edge distance of the bolts to the spar cap can violate the minimum distance that common sense would normally dictate...think of the upper spar as being pushed into the fuselage, and the lower spar cap being pulled outwards from the fuselage, rather than supporting plane, and the above paragraph makes more sense. And as Chris wrote earlier, friction doesn't count in the calculation, mainly because the wood will likely "creep" over time so that the tension is relaxed, although friction is always nice to have to keep the wings from wobbling up and down on the ground. Mark Langford ML at N56ML.com http://www.n56ml.com
KR> VW engines
I was just reading an article about converting a Type 1 Beetle engine to a Type 4 setup, and they cite the difference in weight to be about 26 pounds, assuming everything else is equal. I think GPASC calls the Type 1 160 pounds, but that doesn't include the exhaust system (not sure about the hub) so that would still be under 200 pounds. By contrast, I weighed my Corvair with "everything but electrons in the wires and fuel in the lines", including exhaust, hub, plug wires, plenums, everything, and it was right at 245 pounds. Some folks call the Corvair a 220 pound engine, but it all depends on what you count, and what the basic engine includes (starter, hub, exhaust, hub, alternator), all of which was included in my original Corvair weight estimate. See http://www.superbeetles.com/Tech_talk/jan2.htm for some interesting stuff on Type 4s, and cooling in general for VW engines. There's a lot out there to read about Type 1's and 4's both...enough to keep your average person busy for a year, I'll bet. I'm going to give that up for the day though, and do my best to clean off my workbench, since it's too icy to even walk outside... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> VW engines
Mike Stirewalt wrote: > Would somebody take the time to explain why the Type IV engine is not > the engine you usually see in homebuilts. Why is the Type 2 favored? The small 1600cc based Type 1 is what you see in most aircraft. The larger, more robust 1700-2000cc (from the factory) engine is usually referred to as the Type 4, since it mostly came in Type 4 VWs. That would be "fastbacks" and station wagon 411's and 412's), as well as the Porsche 914 and later air-cooled buses. Earlier buses used the Type 1, with later buses using the Type 4 engine (from about 1972 on) The buses themselves (not the engines) are called "Type 2"s, but the engines in later buses and Type 4 VWs are essentially the same. The Type 4 is a much better engine than the Type 1...it's VW's "fix" for the issues Type 1 engines have. The "problem" is that there were not that many Type 4 engines built compared to Type 1's, and when they were built, they were soon overtaken by the far superior (for auto use) water-cooled engine. So no aftermarket emerged to create replacement parts for the type 4, unlike the Type 1, which flourishes still, with many choices for every engine piece you can think of. Type 4 parts are harder to find, and therefore, several times more expensive. They are a better engine, with better reliability and life, however. There's a lot more on this at http://www.n56ml.com/kvw.html , from back when I was planning to use a Type 4 VW, but discovered the Corvair. I still regret selling my Type 4...I sure wish I had it now! Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Tail Addition
Wayne DeLisle Sr. > What is the height in inches of the tail post for the KR2S? My 2S > supplement for some reason doesn't give a measurement for it. I > finally found my original KR2 plans package and the tail post is > shown as 40" . Well, the drawing doesn't actually have a scale written on it, but a quick measuring job shows that the two 14" dimensions are 7" long, so it's a quarter scale. The tailpost measures 10.5" so it's 42" long. I added something like 4" to it on N56ML and added another two above it in the form of a rudder horn, and the slipping capability is phenomenal. Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Tail Addition
"Steve" wrote: > Mark , how much extra width would you recommend? I don't know if we're talking KR2 or KR2S, but I added 6" to both ends of horizontal stabilizer, while leaving the elevator the same size, and was quite happy with the stability of N56ML, an S. A KR2 could stand even more, assuming it's strong enough. The spars probably aren't "designed" for that, but given that I've never heard of a tail spar failure, there's likely some room for growth there. Troy Petteway did this, but "fixed" some of the elevator to the horizontal stab to reduce the elevator area, and loved the result. See http://www.n56ml.com/troy/ for more on that. The vertical stabilizer and rudder on N891JF (a KR2), could stand some lengthening as well, but I'm not sure I'll do that, because it's good to have a stock-built KR2 so I can appreciate the KR2S that much more! Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Tail Addition
bjoenunley wrote: > Does anyone see a problem with adding the white portion in the picture to the tail for more stability? That will help, but the same material further aft on the ends of the stabilizer (leaving the elevator the same size) would be more effective, and easier to build, since it's simply an extension of the existing airfoil, and the existing h/s would act as your sanding template. I'd make it out of foam sanded to shape and covered in two layers of carbon fiber, personally. It would be out of the prop stream and in smoother air, if that's even a consideration. If you like that way that looks though, it will help. Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Tail Addition
bjoenunley wrote: > Does anyone see a problem with adding the white portion in the picture to the tail for more stability? That will help, but the same material further aft on the ends of the stabilizer (leaving the elevator the same size) would be more effective, and easier to build, since it's simply an extension of the existing airfoil, and the existing h/s would act as your sanding template. I'd make it out of foam sanded to shape and covered in two layers of carbon fiber, personally. It would be out of the prop stream and in smoother air, if that's even a consideration. If you like that way that looks though, it will help. Mark Langford ML at N56ML.com http://www.n56ml.com
KR> speed brake attach
Paul Visk wrote: > You got a good point Larry. Even with soaking the holes with T-88. Are wood screw good to use for the long term. Sometimes wood screws are simply the best choice. My speed brake is installed with a bunch of #6 wood screws on about 3" centers. They screw through a piece of 5/8" spruce epoxied to the bottom of the aft spar, and then into the lower spar cap as well. They aren't going anywhere, T-88 on the threads are not. Yes, I'm the guy with the 130 mph speed brake. See http://www.n56ml.com/n891jf/speedbrake/ for details, also I'm pretty sure Paul's already seen it... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Motor Mt thrust line
Mike Arnold wrote: >Is there a specific thrust line in reference to the top longeron? My Corvair engine sits about 2-3/8" below the longerons. This worked nicely to keep the intake manifolds and distributor just below the contour of the cowling, and smoothly integrated into the propeller's spinner. See the two photos at the bottom of http://www.n56ml.com/ for how it turned out, and http://www.n56ml.com/corvair/mount_fit.html for details of the mount and cowling relationship. This still gave me about 8.5" of clearance below the prop with a 54" diameter prop, using small 5x11.4" tires. Also, handling properties with throttle changes worked "as expected". Short of anything ridiculous, put it where it needs to go to optimize your engine's shape, while keeping over-the-nose visibility in mind, especially if you're building a tailwheel plane. And of course, weight and balance as far as the distance from the firewall. There's a new sunset photo at the top http://www.n56ml.com/sunsets/ , taken late yesterday after another great 1.5 hours in the KR2... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> how likely to sit in one?
David M. wrote: > How likely are KR2S owners going to be to allow me just to sit in one > and see if I fit, please? :) I doubt anybody would have a problem with you sitting in their plane. No two KRs are alike, but legroom is almost cast in stone for any normal person, because your backside has to fit in front of the aft spar...otherwise you'll need a VERY tall canopy. Rudder/brake pedal is another issue...it must be kept compact. The only "easy" way to get more legroom is to add 2-3 inches inches in between the main spar and firewall during construction, which will likely rule out heavy engines unless you also put some weight in the tail, or can keep the engine very close to the firewall. Mine has a Corvair with an alternator pulley that's about 1/2" off the firewall, but I compensated by putting heavy stuff like the ELT in the back. If you're heavy, you may not have that problem...it's all a matter of planning and what the weight and balance sheet says in the end. If you are considering buying one, there's no easy way to figure out if you'll fit other than trying it out or comparing yourself to somebody similar. The beauty of the KR is that you can make it as tall as you want when you build it. In fact, the overall height of the canopy is not even defined in my copy of the plans...I measured it off the plans drawing and the Dragonfly canopy came pretty close to that (it was something like 17.5" above the longerons at the highest point). If you're over 5'-10", you won't fit in my plane from a height standpoint. Buying a flying KR2S is almost a moot point...they rarely come up for sale. Larry Flesner's plane is at the other end of the scale. He's a tall guy, and he even has a few inches of headroom with headset and hat on, but his canopy is completely different from mine, as are most KRs. Build it to fit, and it will fit you. Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Convenience Map
TIME OUT ON THE CONVENIENCE MAP!!! While this is a useful thing to have, it doesn't require the interaction of 25 emails in one day to set it up and get it running. Does the setup require the interaction of 800 subscribers? I don't think so. Please keep the list clutter to a minimum while ironing out the details. It's probably a good time to remind listers about the rules, which apparently some folks have yet to read or comply with. Once again, the list rules are at http://www.krnet.org/info.html. This link is also at the bottom of every message sent out, sometimes several time, thanks to those who don't delete all that crap from the bottom of their emails. Smart phone users are the worst offenders, either because they don't spend the time to delete the majority, don't know how, or just don't care... Mark Langford, KRnet Grinch/Grouch ML at N56ML.com http://www.n56ml.com
KR> VW + Prop
Pierre wrote: >The engine is a standard VW 2 liter Kombi engine. 70 HP tells the story, but you should still be able to a 52x48 prop up higher than that. I still say that one prop maker's pitch is not necessarily the same as another's. The good news is that it's a Type 4 engine, rather than a Type 1. With a stroker crank and larger pistons and cylinders, you turn that 2000cc engine into a 2600cc engine that's almost as big as a 2700cc Corvair. That would give you 90 HP. A higher lift cam will likely give you a few more, maybe 95 HP. That should improve things considerably. Parts availability for the Type 4 engine is not so great, since they don't make the heads or cases anymore, but the same can be said for the Corvair. Great Plains Aircraft (GPASC) at http://greatplainsas.com/index.html used to make a stroker crank with tapered hub for the Type 4, but I don't know for sure that they still do. Having just rebuilt a Type 1 that I am currently flying behind, and having put 1100 hours on a Corvair, I will have to say that the Corvair is a very simple solution also, now that the crank issue has been resolved with a 4340 crank. But given limited parts availability for the Corvair in your part of the world, a used O-200 makes a lot of sense for your KR2S, and would probably be less expensive in the long run... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> VW + prop
Mike Stirewalt wrote: > Are you sure you've got a 52 x 54 and not a 52 x 52? Your figures sound > like a 52 x 52. You did some magic ju ju to that engine when you > re-built it recently if you indeed have a Sterba 52 x 54 and are > getting 3450. Sorry...dyslexia there. I meant 54x52. But I'm not sure there's a lot of difference there. I ordered the larger diameter because I'm not very worried about killing the prop (as long as I'm on a runway), and wanted to be able to cut it down if it wouldn't turn up high enough to develop power. I'll probably live long enough to eat those words, however. I had a 52x52 and it would turn up to something like 3700 rpm wide open, which is a little too much for my taste. If nothing else, this lends some credence to my theory that Ed's pitch numbers tend to be on the high side. I got three more hours on it last weekend, and probably 15 more landings. I tried to get Larry and Joe to meet me in West Virginia, but I got these lame excuses like "I'm sick as a dog and may die", and "Sorry, I'm on my way to California". Some people! Regarding the TruTrak ECO, It certainly is perfect for me. I refuse to waste another penny buying more MGL stuff (like $1500 for two servos to get two-axis autopilot out of the iEFIS), so this is a no-brainer, and light. I've requested dimensions, although it appears as though the servos should fit in a KR wing. Not so sure about the elevator though. See photo below (just to make sure I got it right this time). I was going to the hangar to re-torque the prop anyway, as well as adjust the valves again... Mark Langford ML at N56ML.com http://www.n56ml.com -- next part -- A non-text attachment was scrubbed... Name: 54x52.jpg Type: image/jpeg Size: 27262 bytes Desc: not available URL: <http://list.krnet.org/mailman/private/krnet_list.krnet.org/attachments/20151223/3f908516/attachment.jpg>
KR> VW + Prop
I wrote: >I can turn 3200 rpm static and turn it up to 2450 or so > wide open with a 2180cc engine with 8.6:1 compression ratio and 30 > degrees of advance at wide open throttle. Obviously, top RPM is 3450 or so, not 2450 or so. Also, I should mention that I'm now flying a "52x54" Sterba prop on the 650 pound KR2. As the engine gets broken in, I expect the RPMs to come up a bit more also, maybe 3500 or so. And yes, shortening the 48x52 prop may get you there, but I'd still make absolutely sure that engine was putting out peak power before I took to the sky. Best to get all of this done while this winter, while climb rates and engine cooling are good. I do agree that a Type 1 VW on a heavy KR2S is not advisable, and when you throw in high temperatures and high density altitudes, it may be a "winter-only" airplane. My experience with the Type 1 is that it's "cooling challenged" when compared to the Corvair, mainly because head fin area is very limited. Mark Langford ML at N56ML.com http://www.n56ml.com
KR> VW + Prop
Pierre wrote: >> It feels as if I've hit a brick wall. I had a 48(pitch) X 52 prop on my KR2S> (haven't flown yet). The max revs I got was 2,760rpm static.<< Depending on the displacement of the VW engine, you likely need less pitch (as others were quick to point out). The way the prop maker measures pitch is important also. Having had about 20 different props on my KR2S and KR2, I can tell you that the pitch numbers vary wildly, with respect to RPM. Sterba, for example is almost always has higher pitch numbers for a prop that would turn the same RPM from somebody else. Tennessee props tends to be nearer to Sterba than others. If you haven't seen it already, take a look at the prop vs engine numbers listed for fifty different KRs at http://www.krnet.org/kr-info.html . That may help you narrow it down. Another issue is are you sure the ignition timing is correct? It's worth double checking everything involved in making that right (TDC mark, for example). Ignition timing is everything. Checked at 2700 rpm or above for full advance to 30 degrees? That eliminates advance issues. I know it's a real pain to check timing with a a propeller installed, and very dangerous, so I've started doing it before the prop is even installed. Given that I do have a flywheel on the back of the engine for the starter and alternator, it's not going to hurt the engine for a few minutes, and it allows precise setting of the timing without the adventure of a prop being there. What a huge difference in pucker factor! And you know for a fact that the cam timing is dead on? Have you considered having the 48x52 repitched to something a little less? At least that way you have two data points. As a data point, I can turn 3200 rpm static and turn it up to 2450 or so wide open with a 2180cc engine with 8.6:1 compression ratio and 30 degrees of advance at wide open throttle. I would be reluctant to take off with only 3000 rpm with my short runway. Mark Langford ML at N56ML.com http://www.n56ml.com
KR> risk taking?
> In the spirit of Christmas I have to ask, "What would Santa do"? > Reindeer?, type 1?, reindeer? type 1? Oh Rudolph Reindeer don't swallow exhaust valves... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Panel VHF vs handheld?
Mark Jones wrote: > WOW...I guess my ICOM A-24 must be on steriods because I have broken > all of those rules now for a few years and it still operates like > new. I'm sure you're right about iCOM covering their butts, but when it comes to something that expensive, I'm not usually willing to experiment with it if I don't have to, and I haven't "had to" yet. I don't mind taking a calculated risk if I have some insight into the risk, but when it's something as obscure as the components some company put on a PC board, I don't feel qualified to gamble. I do, however, fly behind a VW Type 1 engine, which gives me some standing as a brazen risk-taker... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Panel VHF vs handheld?
Chris Prata wrote: >> One disadvantage is that most if not all handhelds cannot transmit >> when plugged in, too much current. I believe I read that a few wont >> run at all while charging My ICOM A-24 came with the following warnings: CAUTION: To avoid damage to the transceiver, turn the power OFF while charging. NEVER connect the transceiver to an AC outlet or to a power source of more than 11.5 V DC. Such a connection will damage the transceiver. DO NOT charge BP-210N more than 12 hours. Otherwise, BP-210N will be damaged. BP-210N must be charged for 8?12 hours only. These limitations really surprised me. If you can't operate it while charging, this rules out using it as the primary radio in an airplane unless you carry spare batteries, which is a non-starter in my book. Can't hook it to anything more than 11.5 Vdc? That's another non-starter. Can't charge it more than 8-12 hours without damaging the battery? That's just plain unreasonable. I'd have thought a high tech electronics company could incorporate some smart charging capability that's fairly common in the marketplace. So I carry my A-24 in my flight bag when I go on trips as a backup, and that's about all it does for me. Most of the time it sits on my bench. Apparently (if you believe the instructions), I can't even use it to listen to local airport traffic while I'm at the hangar, unless I want to risk completely discharging the battery (another evil mentioned in the manual), or overcharging the battery (even worse, apparently)... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> KT76A and VHF worth?
Chris Prata wrote: >>Hi all, I have a working KT76A transponder, and a Icom A-200 VHF, prob not going into my KR1 project (whenever that gets off the ground). Wonder what they are worth? Xpnder last flown 2009.<< There are two transponders like that on ebay for $500 and $600. I have that same IC-A200 iCOM radio and it works great. They don't make that one anymore, but the newer model is over $1000, so I would expect it to fetch at least $500 also. II'm pretty sure there's no requirement to check a radio every two years, but the transponder and altimeter should be "certified" to read within 125' of each other every two years (which probably applies more to the encoder than the transponder). Mark Langford ML at N56ML.com http://www.n56ml.com
KR> KR2 is back up...
NetHead I'm getting comfortable in the KR2 again, after putting several hours and flights on the new engine. Yesterday I practiced landings with 8 stop and goes at local airports, paying particular attention to rotation speeds, "over the fence" speeds, and doing hard slips to put it right on the end of the runway. Newly installed turnbuckles on the tailwheel cables took all the play out of the tailwheel, and now I feel like I have much better control over the tail-down operation at high speed. I told my wife when I got home that I'm "back in the saddle again". Gotta show you this morning's sunrise, at the top of http://www.n56ml.com/sunsets/ ... -- Mark Langford ML at N56ML.com http://www.n56ml.com
KR> GPASC dual-plug 10mm plugs?
I appreciate all the replies to this question, but I actually made this post last June, the issues were thoroughly covered, and today apparently Donald Laverick accidentally reposted it. There's been a lot of water under the bridge since then, and the stud's been replaced, the engine rebuilt, and heads replaced with some single plug heads...which I've decided will work for me. Thanks for all the replies, however. Maybe somebody else will learn something from them... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Flap or Belly Board wiring
Larry Flesner wrote: > Here are two diagrams. The simple one is a basic circuit with the > "wing" things inside the switch being the contacts in the "center > off" position. The other is the circuit as installed in my KR with > all components shown. It shows circuit with switch in the down > position and the other with the switch in the up position. My setup is similar to Larry's, almost identical, running an ultra-bright green LED on the panel to show that the flap is "not UP". I did put a diode at the limit switches to solve a problem of getting the board up after the limit switch has broken the connection, because I was trying to minimize the number of wires (since I was out of terminals back there). You probably want to use a DPDT switch that has a momentary ON when down (so the flap can be put down incrementally), a fixed center OFF, and a fixed ON up top. I used an Otto T7-231G1, which AS&S sells as their part number 11-00768, which is as described above. There are more details, photos, and schematic at at the limit switches at http://www.n56ml.com/n891jf/speedbrake/ , but the wiring at the main panel switch isn't really there...plus, minus, and the crossed stuff between poles that Larry's schematic shows. Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Gathering videos - Volunteer to turn VHS tapes into digital format?
Stan wrote: > I can convert VHS to DVD if you so desire. Please advise. Thanks, but I've taken Gary up on his offer to convert them. Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Gathering videos - Volunteer to turn VHS tapes into digital format?
Virg Salisbury wrote: > What happened to the videos that did not get given away at a > gathering a while back ? Larry sent me those videos probably a year ago or maybe even two. Like a lot of things, I volunteered to do something that I haven't made the time to do, and to tell you the truth, I'd also have to resurrect a VCR and do some homework to copy these files from VCR tape to make them videos suitable for posting. So...does anybody out there have the capability and the time to copy these VHS videos to MPEG (or some other format that makes sense) so we can put them on KRnet for download? There are five tapes: Covington in 1988, Kentucky Dam in 1991, Covington in 1992, Covington in 1993, and 1997 in Perry. Any volunteers for this job? The only rule is that you have to do it somewhat promptly, like in the couple of months. You can't be a useless slug like me and impede progress! I believe these were all shot by Video Bob. I will try to reach him and get his permission for posting, although I suspect he'd be thrilled at the prospect of putting them on the web for all to see. I haven't heard from him in years, and I know his health was failing then. Thanks, Mark Langford ML at N56ML.com http://www.n56ml.com
KR> 2016 Gathering at Mount Vernon
KRnetHeads, Nobody else has volunteered to host the 2016 Gathering other than Larry Flesner and Chris Collins with MVN, so Mount Vernon, IL (KMVN) is where the 2016 KR Gathering will be held. At least one volunteer is planning to host the Gathering in 2017, and another for 2018, at this point. That works out very nicely in my mind...MVN every third year, and someplace refreshingly different in between! Also, the informal committee has decided to table the notion of creating an official organization, as the need was not overwhelmingly compelling at this time, with the understanding that circumstances may cause a review at a later date. There are reasons for this that are significant but not obvious, but I don't want to put them in an email. It will require beer and a campfire to pry it out of me...or at least beer... -- Mark Langford ML at N56ML.com http://www.n56ml.com
KR> LED bar vs needle for AFR gauge
Craig Williams wrote: >> I am putting an oxygen sensor in the Smith. I am leaning (no pun intended) >> twords the LED bar meter because I think it would require less thought. Just >> pull the mixture until you're in the green. Any real reason to have numbers >> or >> a needle gauge? Assuming it's a gauge with green in the middle and yellow/orange LEDs and then red on the ends (something like a 10-element display), it'll be fine. You'll find that as the sensor ages, the AFR ratio will climb (or sometimes decrease), so the center point will not be green forever, more than likely. The numbers will be useless. So I agree...it requires far less thought. After a hundred hours or so (if running 100LL) you'll start wondering why it seems to be running lean (RPM drop) but the meter will still be reading rich, and that's your clue that you need a new sensor. If you're like me, you'll lean based on a combination of RPM drop and hitting the "correct" GPH level on the fuel totalizer, set at your usual cruise RPM. Once the get the engine dialed in and know exactly what to expect to get optimium mileage, you'll automatically do all of this without even thinking about it. The beauty of the mixture meter is that one glance can tell you in general "rich or lean". That has saved my butt more than once on takeoff when the engine stumbled and one glance said "go full rich dummy!". And if you're already full rich, vapor lock is setting in, and it's time to pull the throttle back and cool the engine off... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Save KRnet...please read!
Long-time KRnet folks have seen this before, but we have a new crop of list members who either did NOT read the rules, or who don't care to abide with them. The list was sent out to all new subscribers. Given that you wouldn't take the time to read the whole list, I'll boil it down to the three most critical ones. Perhaps you can make the time to read them. 1. When you reply to a previous post, please delete the vast majority of the post you're replying to, to reduce the overall size of your post, but more importantly, to keep the same stuff from showing up in several posts, over and over again, which will later show up as hits for an archive search. It's really annoying to do a search for something and have 50 hits, only to wade through them all to find that only a few are new information...the rest are all posts that have been reposted repeatedly. This goes doubly for "digest" subscribers, as you are likely re-posting 20-30 posts if you don't delete most of it. 2. Keep private emails PRIVATE. That means, for example, instead of sending "please send that to me too", or "how much do you want for that" to 500 people, simply send it to the guy that you're addressing only. That's done by hitting "reply all" and then deleting the return to KRnet address before you send it. Pretty simple stuff. You're building an airplane, so I am confident you can handle this. I'm not saying "always" send it privately...most issues that have to do with KRs, engines, FAA regs, all that stuff are of interest to everybody on the list. It's the purely personal stuff that's directed to one guy that's annoying. 3. The size of a post is limited to 250KB. That's plenty for any text post you'll ever send, but if you throw a photo in with that, it probably needs to be under 230KB, unless you also wrote a book, or didn't delete the previous posts to which you are replying. 250 KB is plenty for a reasonably detailed photo of a reasonable size, say 800x600 pixels that's been lightly compressed. Anything with five times the pixels is difficult to view...it leads to scrolling all over the place and the inability to see "the whole picture", which is quite annoying. And reducing the size helps keep the archive small and manageable, and download times minimized. This is important for those with slow internet connections. If you send a post that's larger than 250KB, you'll get a message that it's being held pending moderator approval. Unfortunately, I'm the moderator, and given that I set the limit to 250KB, the chances of me deciding that your 7MB file should be forwarded to 500 people is remote. I don't check on them and let them expire, since you got the message that told you why it didn't pass the 250KB filter, and can act accordingly to repost it. If you don't know how to shrink an image file, there are plenty of free apps to do that for you. One is IrfanView, and after 30 seconds of googling "irfanview shrink file size", you'll know exactly how to do it. If this sounds like too much trouble to you, please refrain from posting photos larger than 230KB to the list. Thanks for saving the KRnet message archive from premature bloating, and making it easier for future KRnet archive searchers to find the help they are seeking, not to mention making the emails a lot easier to wade through. There's a link to the full set of list rules at the bottom of every message, at http://www.krnet.org/info.html . -- Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Phase 1 and Phase 2 flight testing
CraigW wrote: >If that is true and you make a major change like going from a VW to > a Corvair do you have to go back to Phase 1? I'm not sure what the duration would be for a completely different engine, but I hear "five hours" thrown around a lot for a "major change", and 20 wouldn't surprise me. When I went from my 3100cc back to a 2700cc Corvair, I called the FSDO and they said "don't bother us about that little change or a propeller change, but if you change to a completely different type of engine, call us back". I think it depends a lot on what's written in your "operating limitations", and probably even more on who answers the phone at the FSDO! From an FAA website: Each aircraft issued an experimental airworthiness certificate has operating limitations attached. During flight-testing, specific limitations (phase 1) are prescribed for you to show the aircraft is capable of safe flight (compliance to 14 CFR section 91.319 "Aircraft having experimental certificates - Operating limitations".) After successful flight-testing more liberal (Phase II) operating limitations become effective. Examples of operating limitations for amateur-built aircraft are in Order 8130.2, "Airworthiness Certification of Aircraft and Related Products". ___ Mark Langford ML at N56ML.com http://www.n56ml.com
KR> flight #2
Robert Pesak wrote: >>For not ever flying or riding in a KR the flight was surprisingly uneventful<< That's the difference in a KR2S vs a KR2. The KR2S is a much better handling plane, and the nose wheel takes the excitement out of the landings. Welcome to the KR club! Mark Langford ML at N56ML.com http://www.n56ml.com
KR> inexpensive serial data logger, iEFIS
KRnetHeads, I've been waiting something like 18 months on MGL to port their serial data to the microSD card that's plugged into the face of the iEFIS, and after several conversations and assurances, I've finally given up. The iEFIS does have a serial output stream available on a DB-9 connector on the back of the unit, but I was trying to avoid carrying a laptop around to collect that stuff. Been there, done that, didn't like it. I bought the iEFIS specifically to get a simple SD card interface that logs flight data...and it turns out data isn't even logged to it! Instead, an extremely hoaky JPG with a bunch of squiggly lines with corresponding multiple scales is what you get, and trust me...it's useless! There is no data stream of actual numbers that can be gleaned for engine health monitoring purposes. So I started looking around on ebay for a serial data logger, and there are plenty of options these days. The one I settled on is shown at http://www.ebay.com/itm/271999383948 , and it looks perfect for what I need...just wire it to the master and iEFIS serial data output, plug in a microSD card, and data is automatically recorded to a time-stamped data file whenever power is applied. It weighs 4 grams (.14 ounce) and is the smaller than two postage stamps, is 3/16" thick, and cost me $52 delivered. Needless to say, this is far preferable to lugging a laptop around. I'll report back after flying with it, but thought others might be looking for something similar. This should also work fine with a GRT EIS. I may eventually reinstall the EIS, as I consider it far better than the very expensive iEFIS, as an engine monitoring and parameter trend analysis device. If you wonder what I mean by "hoaky JPG" from the iEFIS, take a look at http://www.n56ml.com/iefis/150513_no_alt_no_rpm.jpg and I think you'll agree that it's not only useless, but a complete waste of time to even download and generate. Contrast that with the GRT EIS output, shown at http://www.n56ml.com/iefis/EIS_logging_example.jpg. This is stable, detailed, readable data you can sink your teeth into! Notice how stable these numbers are...quite a contrast to the iEFIS output. More on this later... -- Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Cross-Country flying
Trevor wrote: > Can you guys give me some feedback about the viability of using theKR-2 as > a cross-country aircraft? Is it comfortable for just a single > person? What range are you guys seeing out of your actual aircraft? In good weather, they are perfectly viable compared to cars. Sure, it's cramped, but you get there 3.5x faster, burning less fuel. Range depends on how much fuel you carry. I have 15 gallons and the range is about 350 miles at the "economy cruise" speed I normally fly at in N891JF, 150 mph, with a 2180cc VW engine. N56ML can carry 23 gallons, and gets 40 mpg also, so you do the math. Your bladder and your back are really the limits here. Comfort is a matter of opinion. You're not going to move but a few inches in any direction, so you be the judge, but flying is a lot less stressful...no "left-lane bandits", no cops, no traffic jams. Mark Langford ML at N56ML.com http://www.n56ml.com
KR> 2015 Gathering photos, link enclosed
My 2015 Gathering photos are at http://www.krnet.org/mmv/. Sorry this took so long...it's the usual excuses. There are a few Evergreen Aircraft and Space Museum photos included at the end, but hopefully I can add more later, time permitting. I have a lot more. -- Mark Langford ML at N56ML.com http://www.n56ml.com
KR> 2016 Gathering host? LAST CALL!
KRnetHeads, Some folks have voiced the concern that despite several invitations over the last few months, and the opportunity to volunteer at the recent Gathering, perhaps we should give those people who might want to volunteer to host the 2016 Gathering yet another chance to volunteer. So, I propose that if you want to volunteer to host the 2016 KR Gathering anywhere other than MVN (Mount Vernon, IL), that you do so before the end of October. This is intended to give a prospective host enough time to get their ducks lined up...line up an airport, get the airport staff on board, check to see if you're going to need a million dollar insurance policy, etc, and run it by the KR Community, which I'd argue is defined by the folks on this email list. I'll be surprised if anybody steps up to the plate, especially since Larry Flesner has already volunteered to facilitate the next Gathering at MVN, with help from others. But we're trying to err on the side of absolute, undeniable, inarguable opportunity. Having said this, I also think that 2017 needs to be held somewhere other than MVN, or we'll get in another rut of going to the same old place year after year, but we'll cross that bridge when we get a little closer. No comments on KRnet are required, unless you are throwing your hat in the ring with some details on your plans to host the 2016 Gathering somewhere other than MVN... Thanks, -- Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Electrical System
The Diehl alternator setup on my plane is the old single phase system, and is a permanent magnet ring mounted to the flywheel, with a bunch of coils surrounding it (bolted to the case). The regulator has two AC inputs from the coils, and one output to the battery. I'm pretty sure the coils and magnets are from an Onan generator. It delivers an amazingly steady 14.5V output, and charges anywhere north of 1500 rpms. I have a couple of $1 50A Schottkey diodes that manage the backup battery charging and isolation from the main system. That backup battery is constantly being charged by the alternator (as is the main battery), but a drain on the main side won't hurt the backup side. They are rated at a current that will act as a fuse in case of a short in the main system, isolating the backup from the main. I'm quite happy with the failsafe nature of the system, and the price was right... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> 2016 KR Gathering location...MVN?
KRnetHeads, At McMinnville it was agreed that it may not be fair to the community for so few people to vote on the location of the next Gathering, and that a location (or more, perhaps) should be presented to the KRnet community, since that's where the majority of the KR community exists. It's worth mentioning that given several opportunities, nobody volunteered to host the 2016 Gathering, although Larry Flesner was prepared to volunteer Mt. Vernon, IL at the McMinnville Gathering, until this Internet vote was decided upon instead. So to me, we could just say "the next Gathering will be at Mt. Vernon, period", and I suspect that would echo the sentiment of the majority. But if anybody wants to volunteer to host it, we can add it to the mix and put it to a vote (Survey Monkey comes to mind), or if nobody else comes forward by the end of the weekend, we'll call it MVN and move on. Keep in mind the responsibilities and expectations associated with hosting the Gathering are not trivial. See Larry's short list from several weeks ago, below: ___ Anyone considering hosting a KR Gathering needs to consider the following items. Some are requirements and some just make for a better event. - The desire to act as host for up to 150 people from all points of the country and possible international visitors. - Ability to plan and organize multiple functions for a large group, i.e. housing, meals, meetings, awards, banquet, merchandise sales, etc. - Complete co-operation and support of the local airport and the community. - Facilities: airport with multiple runways would be nice, not required, non towered airport preferred, hangar facilities for KR's a plus, ramp area large enough to handle KR's and visitors, terminal with restrooms and meeting rooms, restaurant on field a big plus, camping on airport a major plus. Not every airport is "ideal" for a Gathering but many airports are adequate. Your desire to host can overcome other facility shortcomings. None of this should discourage anyone from wanting to host a Gathering if you have the desire and adequate facilities. The KR crowd can have a good time anywhere as long as their basic needs are met. Larry Flesner 9 year Mt.Vernon, Illinois Gathering host _ -- Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Several Questions:
T. W. Norman wrote: > > > Tomorrow we are going to break ground on some of the projects I > have before I start putting everything together. My thrust line is 2.5" below the tops of the longerons, and the plane behaves normally with changes in throttle setting. See http://www.n56ml.com/corvair/mount_fit.html for more on that and engine mount construction. Also, my carb heat / heater solution is shown at http://www.n56ml.com/corvair/airbox/. There's a lot of good information in the archives at http://tugantek.com/archmailv2-kr/search. If you'll visit there, and enter the word "thrust" in the "subject" field, you'll get a hundred messages previously sent to the list, most on the subject of thrust lines and locations. Entering other key words will yield equally good results. I'm not discouraging questions to the list, but you can get a LOT more replies and viewpoints in a matter of seconds, instead of waiting a few days to get one or two... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Carb Recommendation
Sid Wood wrote: > Looks like I will have to get a different carb that has a practical > mixture control. That new carb will probably not have a choke; so, > would need a primer system. Along with that would come the hot start > drama. I have an Ellison EFS-3A on my Corvair, with a primer in each log (all 6 cylinders). I only need it when the engine is cold, and even on hot summer days, I give it a little one-second squirt to get things started if it's the first start of the day (that's what happens when the carb is down low, and the engine's up high). It starts shockingly fast when cold, and if parked hot, it starts instantly without any kind of primer activity. No drama there. If anything, the LyCon guys stare with envy at how quick it starts. When it's "cold" and I use the primer, I goose it for a second, wait two or three seconds for it to move closer to the cylinders, and then it fires almost instantly. I get a big kick out of hearing the Cessna guys grinding away for several minutes, battery getting weaker, and I hop in and fire it up and fly away while they're still screwing around trying to get their bird started. The VW with the EFS-2 is exactly the same way. I highly recommend the Ellison. As Steve Makish (who's tried just about every carb known to man on his VW/Subaru/Corvair powered KR2), "put an Ellison on it and you're done". I took his advice... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Carb Recommendation
DJ Merrill wrote: > One of the reasons for installing the Rotec TBI was compatibility with > E10 autofuel, which I use nearly every flight. Ellison's are compatible with ethanol as well, although their website says they're not. I suspect there's either some CYA there, or they were thinking of the higher vapor lock potential and therefore liability. I ran several thousand gallons of ethanol-laced autofuel through my EFS-3A, and when I took the diaphragm out, it still looked great...so I put it back in to continue the experiment. It stands to reason that since the diaphragms were originally used on snow mobiles, they'd be autofuel compatible. Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Fuel tank pressure test
It's worth reminding folks that we are talking very low pressure here, in the order of one PSI or less, if you don't want to blow up your tank. I've checked my lungs with a high resolution pressure gauge, and I can bearly blow 1 psi, for an instant. The balloon method prevents disasters that can happen when using an air compressor for this job. Personally, I build the bottom of the tank and fill it with gasoline for the night, and come back and check it the next day, then install the top onto a bed of flox, and glass the outside of the joint again. By filling the bottom, you at least prove the critical bottom four joints are good before you button the whole thing up. If it leaks around the top, you can either fix it or don't fill it quite all the way up. N56ML's header tank was that way, but I learned from the experience and never had another leak on the other two tanks. Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Gathering photos
Mike Stirewalt wrote: > I really wish somebody would publish an overview of this year's > Gathering - who attended, who won what awards, pictures. I saw plenty > of cameras there but so far I haven't seen any results of what surely > is a treasure trove of photographs. I took quite a few pictures...so many that it will take a while to sort them out and turn them into a web page, but I'll try to get that done in the next few days. As for awards, they were mostly split between Jeff Scott and Kim Niebauer, although there are definitely some honorable mentions, such as Roger Bulla's newly minted plane. They were all very close in terms of quality. I also got air-to-air shots of all the KRs visiting (except for Mike's...he was not around for that), and we owe John Bouyea for that photo opportunity. It was a well-done Gathering. Many thanks to Dan and John for pulling off a great Gathering. I haven't done anything regarding the Gathering photos because we've been riding around Oregon and Washington national parks for the last week, ending up with Mt St. Helens "national monument" yesterday. That was quite interesting. It had recovered amazingly well from the photos I remember from the news way back in 1980...just gray moonscape with zillions of tree trunks laid out like match sticks...all pointing away from the blast zone. It looks a lot better now, and it's good to see how nature manages to recover from that kind of event. More on that (much later) when I do a web page on that vacation... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> KR Organization
For the enquiring minds regarding the establishment of a KR Organization, nothing has been decided, but this has been a topic of off-line discussion for the last few years. What brought it to the front burner at the Gathering was several independent discussions that evolved into a group discussion, which we eventually brought up to the whole group. What we have in mind is a group that's not hinged on just one or two people, but has a real structure, a bank account, accountability of funds, a steering committee, and a committee to choose Gathering sites...basically a system of government (boy that'll raise some hackles), or at least a few guys to help guide the way and herd the cats. But more importantly (to me), we have a few single points of failure here...if I get hit by a truck, does anybody know the domain password or when it's due, or where the data is kept for the KRnet web page...besides me? Does anybody know where the email list is hosted, and how to take over if I'm gone? And if somebody wants to donate $10k to the group upon their death, how could they do that? There are benefits to having some kind of structure, whether gov't recognized or not, and all of these issues need to be reviewed, discussed, and agreed upon by the membership. I don't think this discussion needs to happen on the email list, because a lot of people will quickly bail, given that they are here to learn to build and fly these neat little airplanes. And it was mentioned at the Gathering that even deciding on next year's location should not be decided by such a small group to represent the whole. We'll likely do an online survey to accomplish that. So my hope is that you guys will leave this topic to the folks on the steering committee and get back to KR discussions. We'll handle the rest, come back with some recommendations, and put it to an internet-based vote after presenting the recommendations. Any useful input should be addressed directly to me. Don't expect lengthy replies though. We're currently vacationing all over Washington and Oregon (Bend, last night) so I'm very out-of-pocket at the moment. One of the many benefits of moving the Gathering around a bit... Mark Langford ML at N56ML.com website at http://www.N56ML.com
KR> Double shear WAFs
The analysis of the failure mode of the KR WAFs done by Don Reid starts on page 46 of the set of newsletters located at http://www.krnet.org/newsletter/nl5.pdf . He practically wrote the whole newsletter that month. In another analysis he sent to the list in 1998, Don made the following comment in answering a similar question about the roll of clamping force in holding the WAFs in contact with the spars: "The frictional load can not be used in the structural analysis. The wood will expand and contract due to weather, the metal in the fittings and bolts will expand and contract with temperature. The ONLY way to calculate the stresses is to assume that they are transferred in the bolts bearing on the wood." This is steel on wood, of course, rather than the steel to steel joint that we were talking about, but shows that neglecting friction is not uncommon. The page before Don's article (page 45) was Jim Hill's KR2. He passed away several years ago now, but this plane was my first KR ride, and Jim turned out to be one of my very best friends. I now own his hangar. A lesson learned was that he hooked up ram air to the front of the carb and went for a test flight. On climbout the more speed he picked up, the leaner it ran, until it finally quit on downwind. Problem was the airport was one-way due to high trees on the end, so he landed very long and ended up in the cotton field off the end of the runway, breaking the tail off the plane. This was about the time I'd done the tail airfoils, so we outfitted his plane with the new horizontal and vertical stabs, rudder, and elevator, and added another bay to it to make it "almost" a KR2S. He reported the difference was amazing. My point though is that even a simple change like ram air can make a huge difference. Our theory was that pressurizing the carb without pressurizing the float bowl reduced the gravity fuel flow to a level the engine could no longer run on. There was a little tube hanging around that should probably have been connected to the ram air source. At least I think that was a float carb...if not, the tube was an overflow or something...that was a long time ago. But the fact remains that even something as simple as adding ram air can be a serious matter with unintended consequences. For those who haven't looked through the newsletters, you don't know what you're missing. Time spent reading these things will save you more time than it takes to read them, and probably answer a lot of questions that you didn't know you had. The rest are at http://www.krnet.org/newsletter . See y'all in McMinnville...arriving early Thursday afternoon... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Reaming WAFs
Nobody's shown me a torque for KR wing attach fittings. It's not in the plans. Why is that? Because friction was not even considered in the analysis of the wing attach joint. It was a pure shear calculation. It's simply a pinned joint, and safe enough on that basis alone. Although I'm certainly not advocating anybody do this, you could likely fly around with cottered pins in place of the bolts to keep them from sliding out of place, and you'd be fine. I'm pretty sure there are airplanes and ultralights that use simple pinned joints. Sure, torquing the bolts to some reasonable number is the common-sense thing to do, and as Larry pointed out, people do exactly that. Calculating optimal torque for a lubricated fastener and nut is commendable, but not necessary. I'm a mechanical engineer, and recognizing that it's simply a pinned joint, I just torqued them by feel and got on with my business. Sure...considering friction would be nice, but the designer simply can't count on these connections being done perfectly, so he designs them to be foolproof, and then add a factor of safety on top of that. That's what we're dealing with on these WAFs. After all, this plane was touted as being buildable with only simple tools... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Reaming WAFs
Sid Wood wrote: > I had understood that the WAF bolts in shear were a backup for the > real attachment: The clamping action due to the bolts squeezing the > two outer and inner WAF plates together. The stress guys I've worked with over the years don't even consider friction as a useful force in a bolted shear joint calculation, and don't include it in the analysis as a result. This includes NASA, ASME, and military work. Your mileage has obviously varied... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Reaming WAFs
Matt Quimby wrote: >> I?vegot my wing spars aligned and attached my wing attach fittings. The next step, according to my plans, is to ream the inboard-to-outboard fitting holes from 3/16" to ??. This being obviously a pretty critical step to get right, I?m looking for some input on how some other folks accomplished this task successfully (or, conversely, what methods caused problems.>> I think there's been a misunderstanding somewhere. The 3/16" holes are used where #10 (3/16) bolts hold the WAFs to the spar caps on all WAFs. The only reaming that is done (and it's not always necessary) is at the WAF fitting bolt holes where inboard and outboard WAFs connect together. The reaming is to enable a bolt to fit through the hole because they are often undersize to make sure it's a very tight hole with no slop. Another part of this is that even AN bolts are not all exactly the same diameter, so the purists would buy several reamers .001" apart and shoot for perfection. Mainly you just want a round hole that's a tight fit, and a drill bit really can't get you there (their holes are somewhat triangular when drilled in thin material). More than likely the WAFs were either machined or laser cut, to the holes are already round, but perhaps slightly undersize due to coatings or burrs (laser cutting). I'd measure your bolt diameters and order a reamer from McMaster Carr that fits them. More than likely though, a plain 3/8" reamer will be "close enough". See http://www.mcmaster.com/#reamers/=ypf185 and look for the "decimal sizes" about a third of the way down. Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Rudder hinge play
The plans have always called for only two rudder hinges, one is also the lower bellcrank, and the other is just a hinge. The three hinge thing came from Australia's aviation authorities, if I remember correctly, or at least the elevators gained a hinge per side from them. I'm not sure about the rudder. Dr. Dean and I may have been some of the first to go with three for the rudder, although two are probably fine in retrospect. More of that "beefing up" that I rail against...and I did a bit of it myself. All this stuff adds up to real weight in the end! Having said this, I've seen plenty of KRs with more than 1/8" of play in the top hinge, but never heard of one fluttering. Still, it shouldn't be that tough to get the rudder off to rebush the hinges. It's unlikely that the steel bolt is worn...almost certainly the 1/8" thick aluminum would be the wear item... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> fuel tank for kr2s
Stan wrote: > My plans arrived and I am reading the manual. Quick question for the > group. Some have made the stub wings fuel tank directly in the wing > from fiberglass and others have made them from aluminum. After hearing all the time, pain, and cost that Dan Heath went through to build his aluminum tanks, I'm still using vinylester, foam, and fiberglass. I built an 8 gallon wing tank in one day (way less than eight hours of actual work) a few summers ago, and it's never leaked a drop. Vinylester is impervious to ethanol and autofuel, and I've never had a problem with it, despite running at least 5000 gallons of it through my tank. There is something to be said for aluminum...generally if it doesn't leak in the beginning, it likely never will, and you don't have to worry about what kind of fuel you're putting in it, but you may discover issues with the sloshing compound later on. But I'm sold on the speed and simplicity of the glass tanks. There are links to the tanks I've built so far at http://www.n56ml.com/kft.html http://www.n56ml.com/kft.html and http://www.n56ml.com/900hour/ The last one shows how you make a "ledge" to set the top on as a last step. Once you have ledges all the way around the top, put a generous bead of flox on it, all the way around, and then press the top in place and weight is down at the ledges to insure a good seal. Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Fuel capacity
Paul Visk wrote: >> Yesterday I filled my out board wing tank and found it holds 10 gallons. With my stub wing tanks of 4 gallons each. I want to add a 10 gl header tank to help with cg. Total of 38 gallons. What are some of fuel capacity of some of the bigger tanks out there? I'm thinking this might be a little to much. I'll be putting on a 3.0L Carvair.<< My 3100cc Corvair burns right at 4 gph running 160 mph economy cruise. I could burn more, but the engine is very happy at 3150 rpm, and any faster starts burning way more fuel than the speed increase warrants. So 24 gallons is 6 hours of flying, maybe 5 if you consider the higher fuel burn of climbout and the half hour required reserve. Neither my back nor bladder would stand much more than four hours, so that's plenty for me. Keep in mind that any fuel capacity that you have will count against your gross weight, which is another reason I deleted my header tank entirely, even after having built it completely. Keep in mind that the bigger your header tank is, the more difficult your wiring behind the panel will be to access. I've put a lot of hours on N56ML with no header tank at all, and I've never missed it. Three eight gallon wing tanks gets me there just fine... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> "new" airfoil sweep
Duh...504x, not 405x! At least I got RAF48 right. For more on this airfoil, including free template download, see http://www.krnet.org/as504x/ Mark Langford ML at N56ML.com http://www.n56ml.com
KR> "new" airfoil sweep
Jon Kimmel wrote: >> Something I found interesting with the new airfoil is that it looks like the sweep is different than what is in the plans.<< The sweep is different because the airfoil shapes (AS405x and RAF48) are different with regards to thickness vs coordinates, so to make the airfoil fit the stock dimensioned spars, a slight fore/aft adjustment had to be made to get the best fit compromise between airfoil and front and aft spar dimensions. This was done at root and tip and then cross-sections were cut through the wing model at the Y-axis template locations to define the scale and spar locations at those cross sections. The term "new airfoil" seems funny now. It's been so long since I made those templates I'm starting to forget the details! It was inevitable, but time has proven that it's a worthwhile improvement, despite the naysayers It'll take a few beers to make me finish that sentence at KMMV! Also, Richard Mole, an English aerodynamicist and good friend, did a "full blown" analysis of the KR2 at about the time of the new airfoil inception (20 years ago now!) and concluded that the aft 2" of the CG range was unsafe. This was many years after the first KR2 pilots concluded the same thing, the hard way. This was done in way more detail than is usual, including stability derivatives and considering a lot of characteristics specific to the plane. I think his words were something like "I sure hope nobody's tried to fly one of these with the CG that far aft!". Anybody wondering how far forward you can fly a KR, consider N891JF. Jim Faughn set the CG with him and full fuel right at the forward end...exactly on it. It's not a handful in smooth air, and will do the phugoid thing all day, as long as it doesn't drift off left or right. Needless to say, it requires some nose-up trim to keep it level, but it still turns in some respectable speeds and efficiency, even with the RAF48 airfoil. Mark Langford ML at N56ML.com http://www.n56ml.com
KR> the NEXT KR Gathering, 2016
Craig wrote: > Hope someone form the right coast or near there will make a pitch. I think Larry Flesner will make a pitch for Mount Vernon, and unless somebody has something considerably better, I'll vote for it, and I'm the guy that wanted it to move around a bit. But once again, here I am about to travel to Oregon for a Gathering, and I wouldn't likely have visited that part of the country without the incentive. I think Mount Vernon is such a good place, and so centrally located, it's just about the perfect Gathering location, but I also think it should move around. Chino was an excellent choice, given it's practically the birthplace of the KR, and I expect McMinnville to be pretty cool too. But I'd be fine with going back to Mount Vernon next time around. It all depends on how the folks at the McMinnville Gathering vote! By the way, I meant to name this thread "2016", rather than "2017". I don't even know what year it is anymore... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> KR2 articles in Sportsman Magazine, Newsletters
In today's EAA "e-Hotline" newsletter, there's a link to some recently posted Sportsman Magazine articles by Jack Cox, including three KR articles. See https://archive.org/search.php?query=sportsman%20pilot&and[]=subject%3A%22KR-2%22 for that. If that link doesn't work, try http://spirit.eaa.org/ehotline/issues/150813.html. And for those who've recently joined KRnet, there's a great stash of 287 KR Newsletters at http://www.krnet.org/newsletter/ ... -- Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Triple Tree
I guess I have to correct my post. LAST year it coincided with the Gathering, but not this year, apparently. There is something about a gorgeous 7000' x 400' wide grass runway that appeals to me, everything else aside. Next year for sure! Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Triple Tree
I planned on going this year and last, but the Gathering coincides with Triple Tree again. Maybe next year we can avoid that... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> the NEXT KR Gathering, 2017
As we all know, the location of the next KR Gathering has traditionally been chosen by those who are attending the current Gathering, as one of the last orders of business at the Banquet. If somebody is planning on volunteering to host the Gathering somewhere next year, please consider the responsibilities that are associated with it before volunteering. For example, you should be doing a lot of homework regarding local EAA and/or airport support. Larry laid out the many considerations in his recent email (below), so a review of his post would be a smart move. Regardless of the location, whoever makes a pitch should give us a "heads-up" at least a week or two before the Gathering so that attendees will have a chance to "vet" the proposed location ahead of time, rather than having to take the word of the pitch man at the Gathering, and voting on it ten seconds later. We have the Internet now...might as well take advantage of it. I was a big proponent of moving the Gathering around, even as far as Chino, despite Mount Vernon being the perfect place for it. I enjoy flying to different places and seeing different parts of the country, and moving the Gathering around was a great way to do that. Before we "settled down" at MVN, the Gathering was typically held for two years in a row at various places around the country, although admittedly mostly in the central and east, rather than the west. I missed Chino but expect KMMV to be every bit as good, and I'm looking forward to it. Having said that, I'm fine with MVN being the chosen airport every second or third year, and we're coming up on the third year. I was very much looking forward to flying N891JF out to the Gathering, but given that the swallowed valve affair completely killed the engine, several car issues that are consuming all spare time (ever do a valve job on an 5-valve-per-cylinder Audi 1.8 Turbo engine?), and the ever-looming JOB, I haven't touched the KR since returning from OSH. I'll be at KMMV via Delta airlines, however. See reminder from Larry Flesner, below: -- Anyone considering hosting a KR Gathering needs to consider the following items. Some are requirements and some just make for a better event. - The desire to act as host for up to 150 people from all points of the country and possible international visitors. - Ability to plan and organize multiple functions for a large group, i.e. housing, meals, meetings, awards, banquet, merchandise sales, etc. - Complete co-operation and support of the local airport and the community. - Facilities: airport with multiple runways would be nice, not required, non towered airport preferred, hangar facilities for KR's a plus, ramp area large enough to handle KR's and visitors, terminal with restrooms and meeting rooms, restaurant on field a big plus, camping on airport a major plus. Not every airport is "ideal" for a Gathering but many airports are adequate. Your desire to host can overcome other facility shortcomings. Finally, I was lucky to have $1800 passed along from Steve and Linda Bennett so I had no out of pocket expenses the first year I hosted. With the support of the KR community we grew the financial account to $5000 over the nine years at Mt.Vernon. $4000 of that was passed to Steve for last years Gathering and the last $1000 went to Dan for this years Gathering. I've not seen a report on last years Gathering and, not knowing how successful this years event will be, there may or may not be up front money to support the event. Consider the possibility of needing up front money for hats / shirts, banquet facilities, and the like. None of this should discourage anyone from wanting to host a Gathering if you have the desire and adequate facilities. The KR crowd can have a good time anywhere as long as their basic needs are met. Questions?? Larry Flesner 9 year Mt.Vernon, Illinois Gathering host -- Mark Langford ML at N56ML.com http://www.n56ml.com
KR> KR engine mount?
I received the email below from a guy that is looking for an engine mount for his KR1.5. It sounds like the one on N891JF, which isn't for sale, and doesn't help him. But does anybody have a mount like this for sale? If so, please contact me and I'll forward your contact info to him. Thanks, Mark Langford ___ I'm still in search for a VW mount that is a bolt-up to the four each 4-stud attachment points.The Great Plains mounts shown in their catalogue have single bolt attachment feet, not the quad feet that I need to use the present stud patterns. The upper firewall attachments are 22 1/8" apart , the lowers 23 1/8". Upper to lower spread 13 3/8" (center to center) Do those figures bring anything to mind? Thanks again, Keith __ Mark Langford, Harvest, AL ML "at" N56ML.com www.N56ML.com
KR> Bulkhead fuel fittings
Oops, meant to say 3/32" plywood reinforcement, rather than 3/16". Every extra bit of weight matters... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Bulkhead fuel fittings
It occurred to me that you may be planning on using the spar as a mount for a fuel selector valve (which I would also leave out...but that's just me). Even then, I'd find a different way to mount it, such as reinforcing the web with another small piece of 3/16" plywood locally, or an angle bolted with about three #8 screws to the web and/or spar cap. I have dual wing tanks on N56ML with no selector or "off" valve, and that has worked quite nicely...never hiccuped a single time for lack of fuel except once as a test...when I deliberately allowed one tank to run dry to see how it would recover. Recovery was almost instant, so it was a non-issue. Mark Langford ML at N56ML.com http://www.n56ml.com
KR> dropped valve
Dave Feiger wrote: >> If I do a rebuild I will use the Manley SS exhaust valves; shied away in the past thinking that they would be softer and more apt to burn??? << There are some cheap 304 stainless valves out there that will mushroom quickly on the tips if you don't use swivel feet, but if you buy Manleys you won't have that problem (although I wouldn't run a VW engine without swivel feet). I've been running Manleys in my 2110cc '74 Karmann Ghia since 1978, and that engine now has well over 200,000 miles on it. This is based on 35 year-old information though, so some research as to exact material strength is probably still in order (disclaimer). and Earl Klinker wrote: >> Was this the #3 exhaust valve? In my case it was number two. The deal with number three only applies to cars because the oil cooler obstructs the cooling air to the number three cylinder, which is not applicable to most aircraft engine installations. Having said that, temperature balance depends on the cylinder baffling. Number one and three would run hotter than number 2 and 4 without some baffling to prevent it, so there is some truth to that, because they are at the rear and are fed air that's already been warmed by 2 and 4 out front otherwise. Balancing out the temps is something done during early flight testing, but does require four CHT probes. CHT probes under the spark plugs will read a LOT higher than probes under the head studs, but it's apparently debatable as to which one you should go by. I choose to go by my standard on the Corvair (and the probe location that spark plug CHT probes are designed for), under the plug. If you want to feel good about your CHT temps, the head studs are a great place to put them! And with only one CHT probe, you're pretty much clueless as to balance. As for Microbuses, I worked at Prestige Motor Cars in Las Vegas (the VW dealership in town) for two years around 1980, and during the summer the VW busses would be lined up at the gate on Monday morning...victims of the heat, climbing the mountain from California, and then coasting down the NV side pulling a high vacuum. That produced a lot of sucked valves. I should have known better and replaced those valves (whoever made them) with the forged stainless valves I had on the workbench. That one's on me, and if nothing else, should be a warning for others... Mark Langford ML at N56ML.com http://www.n56ml.com
