I have a friend and neigbor with the C85/0200 mod. He claims no increase in top speed, but it climbs like a homesick angel now. I will have to ask him what prop he has.
--- In [email protected], "bigbrownpi...@..." <bigbrownpi...@...> wrote: > > I'm very interested in how the 7148 will work with my Don's Dream Machines > C-85/O-200 STC engine. I'm expecting slightly better cruise speed since the > engine can put out around 93 HP at the 2575 RPM limit. Even cruising at 2400 > RPM, I should be putting out more HP than a C-85 at the same RPM, while 2400 > is the equivalent of 75% economy cruise on the O-200. But where I really > expect to see a difference is climb performance. Not only will the engine be > producing more torque, but I should be able to climb at a higher RPM than the > 2100-2200 I normally saw with my old C-85. > > Even though the 'coupe has a reputation as a "clean" design, I really think > our big fat wing is what limits the speed potential of the airframe. (That > and the Vno and Va limits!) > > Dave > > > > --- In [email protected], "Donald" <DonGeneda@> wrote: > > > > > > > > Where I get lost in all that, is the figures get skewered by available > > horsepower, drag, and such. In theory one could get some high number > > pitch, and cruise 150 mph in a coupe. I wonder if someone has ever made a > > chart, listing takeoff distance, climb rate, and top speeds, perhaps on a > > chart so one could make better choices. > > For instance I am told that I will be quite disappointed with my McCauley > > 71 by 51 on the C85 engine, but I hope it will cruise with the big boys. > > > > . > > --- In [email protected], "Ed Burkhead" <ed@> wrote: > > > > > > > > > Larry, > > > > > > I presume you have an O-200 in your Coupe? The STC for putting the > > > O-200 in Coupes calls for the regular C-150 prop to be used. (Many > > > installations on LSA eligible 415-C and 415-CD planes used that STC as > > > "accepted data" even though they didn't actually use the STC to > > > authorize the installation.) > > > > > > On a Coupe, the pitch called for makes it a climb prop with a cruise of > > > only about 108 mph but with quite good climb. Sorry I can't remember > > > which pitch is called for in the STC. > > > > > > The first number is the length of the prop. The second number is how > > > many inches forward the plane would move (with no slippage) on each turn > > > of the prop. (Slippage usually runs around 5%. > > > http://edburkhead.com/Ercoupe/enginepropeller_efficiency.htm ) > > > > > > Thus, a pitch of 50" goes forward farther than would a 48." The flatter > > > 48" is better for the low speeds of a climb so it gives you greater > > > climb. > > > > > > Ed > > > > > >
