Mark, well said. From my engineering days, I was so frustrated by Product Assurance types that always wanted to wait for more databefore accepting the obvious.. Our "experimental " category is supposed to be a learning process, using past good practices wherever possible. Nitriding cranks is a perfect example. I had a Jodel D-11 with and engine older than I was (that's old). The new buyer had the crank ground and polished, (and it'll bet not nitrided). It failed very shortly after the "automotive" overhaul, and the aircraft was destroyed landing in a cornfield.
It would be interesting to know if it's acceptable practice to yellow tag a reground crankshaft without nitriding. W Wynne certainly makes a real effort to understand and report. Thanks, William. Ron Freiberger mail to ronandmar...@earthlink.net EAA Tech Counselor #4125 Mark said; Having read the comments of engine experts (aircraft, heavy equipment, etc) in the field who's first question was "are you sure that crank was nitrided" (see http://home.hiwaay.net/~langford/corvair/flexplate/problem.html ) is all I need to know. It's considered standard practice in industries in which maximum crankshaft longevity is expected. It's guaranteed insurance of significantly more fatigue resistance for the crank. The reason William didn't use 5 cranks of either type is because he doesn't HAVE 5 nitrided cranks to check, and it would be irresponsible to sit around waiting for them. But seeing 7-8 cracked or broken cranks (most of them in KRs) in the last year is enough for any logical thinker to conclude that there is a problem that needs fixing, and a $50 nitride job is a pretty good step in the right direction. If he kept quiet on this issue it would just be a matter of time before he had a broken crank that didn't just result in a forced landing and a trashed engine, but would involve totalled airplanes and/or deceased friends... Mark Langford, Huntsville, Alabama see KR2S project N56ML at http://home.hiwaay.net/~langford email to N56ML "at" hiwaay.net _______________________________________ Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net please see other KRnet info at http://www.krnet.org/info.html
