Club Homepage Forums Classified Ads Buy & Sell - Everything But Airplanes Looking for a 0-200 rebuilt crankshaft

Can anyone explain to me how this STC would work with an already OH'd (ground to .020) but 0 SMOH engine? Is it just a paperwork process or is additional disassembly and/or parts necessary?

Thanks.
Jim

The TCM limits are 0.010.
That company has a STC to turn down to 0.020, and uses undersize bearings.
Once the crank goes beyond that, its junk.If someone was overhauling an engine, and the crank measured 0.020, they could use the STC to continue service, but why you would spend all that money on an overhaul with a crank essentially almost gone is not something I would do. That's like reusing EVERYTHING in your "overhaul" so long as it met the maximum limits.

Agreed, Brian and I hope people understand your statement.

While that's legal, it's also unwise.....very unwise.



Jim

The hangar neighbor next to me has a Luscombe with an 0-200 on it. They just experienced 2 stuck valves, did the rope trick, and the valves stuck again. Also the engine has been on at least 3 other airplanes ( including a homebuilt) before it found it's way to the Luscombe. They have now sent the engine to LYCON for an overhaul.
They told me the cost is going to be around $18K, and does NOT include new cylinders. I guess that is the going rate these days.
So, why you would invest in an engine with a crank DOUBLE the limits of TCM just seems unwise.

20 under is fine...the bearing cost about $800.00 is the main difference. But...if you can find a standard or 10 under crank...that is more better. Superior does good work and you should get good service from a 20 under crank...but it will likely be the last overhaul for that crank. 20 under may seem unwise...but in reality it is a serviceable crank and the structural integrity of the crank is all there and there is no compromise to safety

Interesting discussion, thanks for the info guys. This was more of an educational inquiry for me, not something that I am personally considering. I saw a freshly OH'd O-200 advertised as "experimental only" and was curious as to why it would carry this limitation with the STC available. I presume that the owner had intentions of hanging it on an experimental airframe and didn't need/want the extra cost of the STC.