Debate about Mark Langford's 3rd crank failure

Discussion in 'Corvair' started by Will Aldridge, Jan 23, 2012.

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  1. Mar 28, 2017 #241

    Bill Clapp

    Bill Clapp

    Bill Clapp

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    Iv been flying corvair powered aircraft since 2004 and have well over 1000 hours behind them. One crank failure very early on before nitriding. Never had to shut it down. Now I use either the GM forged crank with nice radii, nitrided, with our IFB bearing system and clocked (90 to #6 throw). Our 120 uses a brand new, hot forged, couterwieghted and stroked crankshaft. Not a problem so far on the many engines we have built and flown to date. I have not used harmonic balancers either since 2006. Our hub load is much lighter and the bearing much more significant that the WW or SPA versions. There was another recent crank failure due to the internal threading of a WW safety shaft . Drilling and taping the inside of a crank introduces stress risers internally and an avenue for failure. I have believed for years that my design is as good as it comes for the design of the engine without overtaxing the original parts or the budget. Only more time can prove that decision wise or foolish. With thousands of hours on our systems it seems to work well. I have hundreds of hour personally behind my products and trust them as much as any other aircraft I fly. That being said, there is still nothing better than being a safe and carefull pilot, being as prepared as able for the capabilities of yourself as pilot and the aircraft you fly. I wond bank and turn a Zenith like I do my Saberwing ... stay within its capabilities. I also do my best to maintain the engine and airframe of the aircraft I fly to a safe level. It would do us all good to remember these tips....It is experiemental aviation though...explore and have fun....challange yourselves and your designs and capabilities....do is safely and wisely.
    Bill
     
  2. Mar 28, 2017 #242

    proppastie

    proppastie

    proppastie

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    Now that you mention it, I have seen factory built that has it so the prop only goes on one way, (1 larger prop bushing) and seen it specified in the manual where to put the prop.....getting old...wet wire computer needs time to access.
     

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