Called Memphis Propeller 800-844-7767. Fixed pitch prop: Repitch $150 to $175 Overhaul $550 Bill
To: [EMAIL PROTECTED]: [EMAIL PROTECTED]: Fri, 9 Nov 2007 11:30:57 -0500Subject: RE: [ercoupe-tech] Climb prop and recommended cruise rpm with C-85 >Or, maybe, the price (to repitch) might have risen to what Bill said.My $200 >was to repitch. Bill's $400 was for an overhaul and repitch.* Is it bad to run >the C-85 engine at more than 2400 rpm in cruise when youhave a flat, climb >prop? No. first off, the engine is approved for CONTINUOUS operation at 2575 >RPMat maximum throttle, i.e. 85 hp. BO times take this into consideration, >so,basically, any power setting up to full power is expected to reach TBO.What >determines power output is RPM combined with manifold pressure.Flattening the >prop results in lower manifold pressure and hence lower powerat a given RPM.* >If the plane cruises at 108 mph with the 7150 prop, is it OK to turn highrpm >to cruise the same airspeed? Yes, up to red line. Beyond that you are busting >the regs.* Would that cause lower or higher stress on the engine than flying >108 mphwith the 7140 prop?Good question. I don't know if you could make 108 >RPM with a 7140 and stayunder redline. On the other hand, you might not make >108 mph with a 7160either, but your manifold pressure would be a lot >higher...Bottom line, at 2575 RPM with a 7140 your manifold pressure and hence >poweroutput would be pretty low unless you were hanging the plane on the >prop.Regardless, a normally aspirated engine running at or below red line >willnot make more than rated power.Regarding higher RPM's bear this in mind: >The same rotating parts as theO200 (essentially) are used in the GO-300 which >is redlined at 3200 RPM(continuous)...John Cooper, A&PSkyport ServicesPO Box >2494996 Delaware TnpkRensselaerville, NY 12147518 797-3064Fax 518 >797-3865www.skyportservices.net _________________________________________________________________ Boo! Scare away worms, viruses and so much more! Try Windows Live OneCare! http://onecare.live.com/standard/en-us/purchase/trial.aspx?s_cid=wl_hotmailnews
