Brodhead Pietenpol Association

Original Posted By: "Clif Dawson"
I am getting my engine ready for WW Corvair College 20 in Michigan. I am dissemblingmy engine to put in forged pistons and nitrite the crank. The originalbuilder assembled the engine and ran it for about 5 hrs. I have logs of thosetest runs. I am finding some interesting things and would like input from someor you guys that are running corvairs especially if you have opened up yourengine. Here is what I found.When I removed the cast pistons one was notably discolored (#3 cylinder) The cylinderitself showed some signs of being hot as it has begun to rust slightlythrough the paint which is not true of the others. I am presuming they wereall painted at the same time. The coloring of the top of the piston shows that it was hot as well. The previousbuilder's logs indicated that during first hour of break in the rt head ran20F to 30F hotter than the other side. I don't know what cylinder the sensorwas on. The head also shows some signs of being hot and the fins are actuallymelted. This looks to me to be possibly from someone working on it with atorch or maybe trying to heat the nut to remove the exhaust manifold. There issome obstruction of air there. The heads were totally reworked before I gotthe project by Larry's Corvair Parts new valves, springs, and one seat welded,I am not sure what action to take here and I am looking for advice.Another issue. The rod inserts show a little scoring. You can just feel it withyour fingernail but the crank is smooth. I was surprised at that for only5 hrs. but have not pulled that many engines apart. I don't know if those surfacespolish out with break in as the inserts are much softer metal than the crank?There is also some vertical scoring on the cylinder walls and I believe the jugswere bored out to 30 over. again a surprise for only 5 hours. I am hopinga light hone will take most of it out.If you have any thoughts on these items please let me know. I am getting downto the wire to have everything ready for college 20. Having to find a new headat the last minute might be a problem. Attached are some photos that are alittle more graphic:I have attached some pictures to help with my explanation--------Jon Coxwell GN-1 BuilderRecycle and preserve the planetRead this topic online here:http://forums.matronics.com/viewtopic.p ... ttachments: http://forums.matronics.com//files/img0 ... __________

Original Posted By: Rick Holland
Why do fiddlers pick on banjo players?Because they can't pick on their fiddles.Always remember that the Banjo Player is the Fiddle Player's best friend.Without him the fiddle would be the most hated instrument on Earth...Clif> being a big fiddle player i like banjo jokes....>> if you throw a banjo player and a guitar player out of a plane at the same > time.... who hits the ground first ??> the guitar player of course....> the banjo player has to stop and tune> jeff> in the bluegrass state________________________________________________________________________________Date: Wed, 27 Apr 2011 20:52:19 -0600Subject: Re: Pietenpol-List: Corvair engine rebuilding

Original Posted By: Ryan Mueller
Subject: Re: Pietenpol-List: Corvair engine rebuilding

Original Posted By: "Jack"
Jon, Piston #3 is darker than the rest probably because of an air leak causing a leancondition in that cylinder. The air leak could be caused where the intakebolts to the head. If somebody put enough heat into the head to melt cylinderfins, there's no telling how warped it is without careful measurement. And whywould someone weld in a valve seat? Or do you mean that the head was weldedup so that a valve seat could actually be pressed in properly? Etiher way,the head got way too hot at some point. I'm not sure I'd use that head even ifthis engine was going into a real Corvair with 4 wheels. I'd also invest in some new bearing inserts if the current ones are scored. Evenif the original person who rebuilt this engine used quality parts in the rebuild,there's no telling about how clean the shop was where he did the assembly,or if he did the assembly work properly to begin with. But as Rick and Ryan already mentioned, WW is the ultimate resource for answersto your situation. He'll surely set you straight when you get your engine toCC #20.--------Billy McCaskillUrbana, ILtail section almost done, starting on ribs soonRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________

Original Posted By: "coxwelljon"
Subject: Pietenpol-List: Dan Yocum mentions slipping the Pietenpol with all 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________________________________________________________________________________Subject: Pietenpol-List: Re: Corvair engine rebuilding

Original Posted By: "tdudley(at)umn.edu"
A couple of days ago I posted with some problems that I was finding in my corvairengine that I am rebuilding. In particular one cylinder (#3) showed signsof having been much hotter than the other. I was concerned about what may havebeen the cause as my engine was supposed to have been overhauled according toW Wynne's manual. There were some things I wanted to change so I disassembledit. I found some problems which confirmed that I need to see just what theother guy did before me. I am getting ready to take it to Corvair College #20in a couple of weeks and re assemble it there. A couple of you suggested contacting W. Wynne. I tried both email and phone tono avail and also emailed Roy's Garage who is hosting the upcoming Corvair Collegebut no response. I was getting frustrated so I started searching on linein the corvair forums and found some pretty interesting info. I have attached2 articles about cleaning out the slag on your cooling fins. Those of youthat are building corvair engines should look at this, especially the illustrations.I took another look at my heads and found that the melted alum. that I thoughtwas from someone going wild with a torch trying to heat some bolts was in factleft over slag form the casting process. My offending cylinder that showed signsof being hot had no air flow through the head at all. I am working on minenow with a keyhole saw but have a long way to go. I'll bet I have a half cupof alum shavings from each head so far. If you don't know what to look forit is easy to miss this.I hosted my EAA chapter 2 weeks ago which included 3 A&P's and a tech councilor.They were really helpful even though none had work on a corvair engine. Ithink I am on the right track now with no major difficulties that a few hundredbucks won't remedy. I got the project pretty cheap so I guess I should expectthat. Just thought I would share what I have learned. Maybe I will meet someof you at Corvair College 20.--------Jon Coxwell GN-1 BuilderRecycle and preserve the planetRead this topic online here:http://forums.matronics.com/viewtopic.p ... ttachments: http://forums.matronics.com//files/head ... ___Subject: Pietenpol-List: Fuselage question