Wow, lots more good stuff. I hope others are not being bored by a newbie asking lots of questions. Mine is an 85hp model, and so far I have not found another C that has had a field approval for an 0200. Many SAY they do, but they are actually STC types in a D model, or the STC for some 0200 parts in the ol 85.. If anyone has a field approval of an 0200 in a C, I would dearly love to have them share their paperwork. I actually have two sets of pants, I bought a new set of Skyports with STC prior to getting a plane, then finally bought a plane with pants! Skyport CLAIMS a 3-5 mph increase with the pants if I recall correctly. I don't have the draggy lights in the gear jobs. Unfortunately I must stay within the Sport Pilot realm. My plane has wingtip lites, belly strobe, and a (skyport)landing light in the left wing only. I choose to keep that weight, I have in the past let daylight run out on me, so Sport Pilot or not, I like lights to get home on! I do have the venturi, think I will lose that soon too.
--- In [email protected], "Ed Burkhead" <e...@...> wrote: > > > Don, > > Ah, you bring up such interesting issues. > > So, you're based at a 5,000' airport? Here's another thought for you - > you might want to consider swapping out your engine for an O-200. It > won't fly much, if any, faster. But it'll climb a lot better. > (Naturally, this depends on the prop you choose and get approved.) > > Yes, it is possible to mount an O-200 on a 415-C or 415-CD. There is an > STC for putting that engine on a 415-D but some people have gotten > approval for the engine on a C or CD. > > In the long run, that may be a very good idea. > > Until you do that, I'd strongly urge you to fly from the high altitude > aiport with a 7146 prop (assuming you have a C-85). > > And, make sure your mixture control works properly. Some idiots will > tell you the Stromberg carb mixture doesn't work. The Stromberg mixture > DOES work just fine (albeit slowly) if it is properly cleaned and hooked > up. Make a change and wait a moment to see the results. With a high > accuracy EGT I was able to tune it to 10° accuracy. If you have the > Marvel-Schebler carb, that is OK. > > As for speed mods, well, there haven't been any. The Coupe is a fairly > sleek airframe which explains its cruise speed with a small engine. (It > also makes aerobatics extra deadly as the plane gains speed REALLY FAST > when the nose is pointed down. Aerobatics of any kind are blamed in > most of the very few in flight break-ups we've had.) > > The Alon canopy is sleeker and accounts for, I think, about a 7-10 mph > airspeed gain (though the Alons also have the slightly larger C-90 > engine). Alons could out climb me and fly 15 mph faster than my Coupe - > but they're not eligible to be flown by Sport Pilots or PPfuSPp. > > The Kinney wheel pants were designed without benefit of computer > aerodynamic design software or even a wind tunnel. They provide > virtually no increase in speed, just in weight. But they do look cool. > > The landing gear mounted landing lights are said to make a lot of drag. > > First, I'd consider putting the landing lights in the wings or cowl. > Moving them to the cowl would be cheaper. Putting one landing light in > each wing maintains the bank information other planes get when you are > tracking toward them - and it's dramatic as you'll see when a Coupe with > gear lights flies toward you. I'd like to maintain that appearance to > magnify your flying safety. > > But, if you are going to fly SP, you might keep the position lights and > strobes but lose the landing lights - you are not allowed to fly after > the end of civil twilight, anyway. > > Venturis hanging out the sides also provide significant drag. For speed > mods, I'd next recommend you change to instruments you can run without > venturis. > > Getting rid of any nose gear snubber cable (added later and repudiated > by the designer) and restoring the nose gear fairing adds speed. Just > adding the fairing to the properly extended nose gear adds one (1) mph > by careful measurement of the designer. Planes with the snubber cable > also have the sissors hanging out in an optimally bad manner. Planes > with the snubber cable AND the fairing reflect a substantial error on > the part of the owner as the fairing would then scoop air and make for > BIG drag. > > An opportunity for real improvement would be good, aerodynamically > efficient wheel pants. This is difficult to design due to the trailing > arm of the main gear. But, very light, very efficient wheel pants might > add several mph to the plane. No one has yet attempted this. > > Modifications of the wings may smack up against an FAA wall. You would > certainly have to have a really extensive engineering analysis, possibly > with an extensive flight test regime to prove the safety of the mod on a > plane that is special. As the only plane flying in significant numbers > that is certificated as "characteristically incapable of spinning," the > Ercoupe is special aerodynamically. Changes to the wing might be > prohibitively difficult. Perhaps the wing tip might be possible. > > Even the fairing between the wing and the fuselage was an integral part > of the spinproof certification as was that small ridge at the leading > edge of the wing near the fuselage. > > Perhaps the cowl shape could allow for some speed mods. Don't forget to > take engine cooling into account. And, don't lose the engine cant to > the right and downward. > > Well, there are some starter ideas. Please keep us posted on what you > get approved and installed and how much difference it makes. We'd all > like to be faster if we can afford it. > > Ed >
