Congrats to your success. You know Sept 18 is just around the corner. MVN is gonna be fun.
On Nov 26, 2017 6:53 PM, "n357cj via KRnet" <krnet@list.krnet.org> wrote: > Hey Guys, > Back near the end of May I decided to pull the engine for an overhaul > for a couple reasons. For more years than I can remember I have had a oil > leak which I knew was from a crack in the block. While this may sound very > on safe it never became a structural issue but only caused me a large > amount of cleaning and adding a quart every10 to 12 hours of operation. > This past winter it became apparent that the leaking was increasing to the > point that it became a real irritant. The thing that made the deciding > factor was during a afternoon flight I noticed a drop in oil pressure while > nearly a hour from home. I never lost pressure but the lowered pressure was > a another cause for concern. I always felt that an accident is a build up > of 3 mistakes and I had 2 already. > I had a block preped by Roy a few years ago and I had a store pile of > parts so I figured a several week turn around and be right back at it. > Well, that didn't work out so well. Through a number of comedy of errors > (not really funny) and 4 separate tear downs and test runs and even a > couple test flights, I finally have everything running great again. The > first big deal was I knocked the block off the work bench when it was > short block assembled. From there i convinced myself that it had distorted > the block and it was trashed. MArk Lankford came to the rescue by sending > me his 3100cc block. I built that all the way up and mounted it to the > plane. I knew that it was very tight build. It proved to be to tight with > high oil temps and scorching a bearing that was tight. So back off the > plane and tear down again. I tore the high volume oil pump apart again and > looked the gears over again. There was no sign of wear at all but using a > magnifying glass I noticed that there were some circular scores just above > the drive gear. The drive gear is a pressure fit to the shaft. It appears > that the gear when up to temps became loose on the shaft and would slip > some. I replaced the drive gear and hoped I had this resolved. > Over this period of time I re-evaluated the case that I had dropped > from the work bench. Other than a dent in one corner of the casting I could > not find any misalignment or damage at all. I re-installed 2 different > cranks and cams to torque and found that the cranks run perfectly true and > free. So I took everything back off Mark's case and started to rebuild mine > again. At least Mark's is all cleaned, painted and ready for him to start > his rebuild. > I built this one up again and mounted it to the plane again. This time > it seemed to go together OK. A couple more weeks altogether and mounted it > back up to the plane again. It started up OK and timing was checked. > Something bothering me...It didn't sound quit the same. I did a test flight > of about 20 minutes around the pattern and it still bothered me. I had one > head temp that was a bit high. But worse yet I had oil all over things > again... That just isn't going to due again. I cleaned the engine all up > again and put the dye in the oil that ultraviolet light shows. I ran the > engine on the ground up to temps for about 15 or 20 minutes. > My son and I pulled the engine again, took it home back on the bench > and search out the oil leaks with a black light in the dark. To my surprise > none of the leaking was coming from where I thought it was. I only had one > O ring on one push rod tube that was leaking a bit. All the rest was coming > from the edges of the top cover. Well at least it was an easy fix for that > part. The noise that was troubling me was the next thing. I just had an > uneasy feeling about the valve adjustments. When I pulled the cover on the > right side I found the middle rockers loose on the push rods. I had miss > adjusted a least one set somehow (inept or incompetent come to mind) I did > not even bother checking any others. I pulled both heads off, push rod > tubes pulled out the lifters. I took each lifter apart in order and drained > them and replaced them in order. Reassembled the right and then the left > sides with all new O rings again. I carefully adjusted the lifters in order > and repeated to verify. > The oil with the dye was left in the oil pan just in case I discovered > leaking again when it was back on the plane. The engine went back on again > yesterday. Everything went well which made the process feel better. Nothing > seemed to be nagging me this time. I finaled everything out this morning > and with my son at the throttle we checked the timing again. The engine > fired right up with just a couple cranks and ran very smooth. Nothing > bothering me this time... sounds great and seemed like it had great power. > After a few minutes of running and warmed up there was no obvious oil leaks > either. > I got everything all cleaned and back under cowl. Started her up again > and did a bit of taxi. Really acting great now and very good power. I > decided that the only way to really find out was to fly. The take off was > good with all temps being very normal as compared to the past 12 years. I > flew for an hour with one full throttle run at 3000 feet just to see what > happens. Like I said the power seems really good. At 3250 rpm she was > bouncing the true airspeed at 183 to 184 mph a solid 3 to 4 better than i > have been able to achieve before. > I didn't mention the details of what was actually done in the rebuilds. > The main bearings and rod bearings were replaced. The exhaust valves > replaced. All valves were lapped. pistons removed and inspected, rings > inspected cleaned and re-installed. New fifth bearing shell installed. New > plugs. New oil pump gears. New silicon exhaust gaskets. New cylinder head > and base gaskets. Mostly all new instrument sensors. all new gaskets. New > bypass spring and piston. Replaced spark-plug wires. Lots of cleaning and > rechecking every part for condition. All in all if it wasn't for the oil > leak that has plagued me I would not have been afraid to have run this > engine to 1500 hours or beyond. > There was a period of times during the past 6 months that i was ready > to call it quits, This rebuild was about the most frustrating thing that I > have ever done. I fully admit that several of the things that went wrong > were fully and completely of my own making. But I flew my plane today and > man oh man does it make it all worth while. > Keep building guys, > The sky is waiting, > Joe Horton, > N357CJ > > > _______________________________________________ > Search the KRnet Archives at https://www.mail-archive.com/ > krnet@list.krnet.org/. > Please see LIST RULES and KRnet info at http://www.krnet.org/info.html. > see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change > options. > To UNsubscribe from KRnet, send a message to krnet-le...@list.krnet.org > _______________________________________________ Search the KRnet Archives at https://www.mail-archive.com/krnet@list.krnet.org/. Please see LIST RULES and KRnet info at http://www.krnet.org/info.html. see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change options. To UNsubscribe from KRnet, send a message to krnet-le...@list.krnet.org
