[Starting a new thread. The reply nesting level in my mozilla window was getting freaky.]
Vivian Meazza wrote: > The engine I'm trying to specify developed 1140 HP at engine > revolutions of 2850 rpm at a boost pressure of 9 psi. It was fitted > with 1:0.477 reduction gearing, which I think means that the > propeller turned at 1360 rpm. Hrm, 1360 RPM is very slow for a cruise value, just over idle speed for a smaller plane. Likewise, 2850 RPM really isn't that fast for a piston engine. It's at the top end of ungeared engines like a Lycoming O-360 or whatnot, but not really very fast for four stroke engines as a whole (my Saturn redlines at 6000, for example). Is it possible that the 2850 number is a *propeller* RPM at max power? Then you'd get a max power engine speed of 5975, which seems plausible to me and avoids the problems with solving for a propeller which "cruises" at a pitch where normal props would be windmilling. Does anyone have good info on whether the cockpit engine speed gauge in a Spitfire (which is presumably what most sources will quote for "RPM") reads engine or propeller speed? Andy _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
