Thanks, that was a help. Figured on a 52 pitch, the MPH would be 118.1818 mph @2400 (in that perfect world) That would mean my 71/50 at 2400 would go 113.6363 mph, I thought it would be faster somehow. Now lets figure in the difference in efficiency between different lengths of props. Gotta make a difference!. Also, with an Ercoupe, there should be some fairly standard of efficiency since the drag would be fairly constant. This is fun!
--- In [email protected], Bill BIGGS <webacr...@...> wrote: > > > The 48" pitch refers to the theoretical 48" the prop (and thus plane) moves > thru the air in one revolution. > > > > So 48" x 2400 rpm=115200 inches per minute x 60= 6912000 inches per hour / 12 > = 576000 feet per hour / 5280= 109.09 miles per hour. > > > > This is in a perfect world. > > > > Bill > > > > To: e...@... > CC: dongen...@...; [email protected] > From: ercou...@... > Date: Mon, 25 Jan 2010 17:42:51 +0000 > Subject: RE: [ercoupe-tech] Re: PROP PITCH > > > > > > > > So far, the replies I have read speak of a change in RPM. My question > related to two props with different pitches turning at the same RPM. The > replies related to a change in rpm. It is common sense that to move just to > move the same amount of air, a 48 pitch would need to turn more rpm than a 51 > pitch. Sooooooooo, in order to have better take off characteristics, the 48 > pitch must be turning at a considerably higher RPM. My Coupe is in the > reassemble stage, else I would put on different props and do the > measurements. There must be someone out there much smarter than me that > knows of a formular that calculates the difference in air movement. Hold on, > I erred, correction, there are many out there much smarter than me. > Lee Browning > > > > > ____________________________________________________________ > Banking > Click here to find the perfect banking opportunity! > > > > > > _________________________________________________________________ > Hotmail: Trusted email with powerful SPAM protection. > http://clk.atdmt.com/GBL/go/196390707/direct/01/ >
