Frank, John Cooper said it beautifully.
I'm inclined to agree with him on all his points. Check your prop stamp and see if you have the prop's history. Call some prop shops recommended by these guys and your FBO/A&P/AI and get estimates. The prices he mentioned match my memory from casually watching the reconditioning/repitching correspondence. Or, maybe, the price might have risen to what Bill said. You can find out tomorrow. The only downside to repitching to flatter is that it cuts down on your cruise speed at a given rpm. With my prop repitched to 7146, my climb was increased to tolerable and my Coupe's airspeed at 2400 rpm was almost exactly 100 mph. Being a timid and insecure type (as anyone can tell you), I continued to cruise at 2400 rpm (except for just a very few instances). Mind you, with a flat pitched prop, 2400 rpm isn't working the engine very hard at 100 mph. Several people including mechanics told me to go ahead and "let it spin" and run at higher rpms. Engine experts! * Is it bad to run the C-85 engine at more than 2400 rpm in cruise when you have a flat, climb prop? * If the plane cruises at 108 mph with the 7150 prop, is it OK to turn high rpm to cruise the same airspeed? * Would that cause lower or higher stress on the engine than flying 108 mph with the 7140 prop? Inquiring minds want to know! Ed Burkhead http://edburkhead.com East Peoria, Illinois ed -at- edburkhead???.com (change -at- to @ and remove "???")
