----[Please read http://ercoupers.com/disclaimer.htm before following any advice in this forum.]----
John; Since I haven't opened my engine up, I'll anticipate that the 1100hr -.010 crank will be out of limits. If such is the case, my plan is to step up to the 0-200 crank STC. What props are listed with the STC for that combo? Are there various STC holders you make a recommendation on this mod or is there only one guy? Another thing, since virtually only the case is used, would it make good economic sense to find a runout 0-200 and scavenge the parts from it? (Crank, cam, rods, lifter, pistons cylinders.) Thanks Al ----- Original Message ----- From: "Skyport Services" <[EMAIL PROTECTED]> To: "William R. Bayne" <[EMAIL PROTECTED]>; "COUPERS-TECH" <[email protected]> Sent: Wednesday, January 05, 2005 4:02 PM Subject: Re: [COUPERS-TECH] HP questions > ----[Please read http://ercoupers.com/disclaimer.htm before following any advice in this forum.]---- > > > At 04:38 PM 1/5/2005, William R. Bayne wrote: > > ...If this was my McCauley prop, first I would check the plane's > > paperwork and see if there is a 377 or one-time STC for this prop to be > > on this airframe and see if acceptable static rpm limits are given. If > > so, I would get a Helmuth-Chadwick balance done (with proper spinner > > mounted) and worry no further, presuming present static rpm is within the > > stated range.... > > The issue is not balance. It's harmonics based on the power pulses and the > resonance of the casting, combined with the same characteristics of the > rotating mass, especially the crank. The crank and prop together have a > resonance that must be considered. > > That said, I retract my original "cry wolf' statement. There are some > interesting boundary conditions wrt rpm limits and the O200 crankshaft when > combined with the C85 prop, but that's not important right now... > > The McCauley 1A/B90 prop is certified for use on the C85 for lengths from > 70" - 78" and RPMs up to 2600. As long as you respect those limits and > don't have an O200 crank, you're likely safe, albeit not legal... > > John Cooper > Skyport Services > PO Box 249 > 4996 Delaware Tnpk > Rensselaerville, NY 12147 > 518 797-3064 > > ========================================================================== == == > To leave this forum go to: http://ercoupers.com/lists.htm > Search the archives on http://escribe.com/aviation/coupers-tech/ > > > > ========================================================================== ==== To leave this forum go to: http://ercoupers.com/lists.htm Search the archives on http://escribe.com/aviation/coupers-tech/
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