Not a speed plane but....
 

the excelleron 50. http://hobbypeople.net/gallery/127564.asp

what ya guys think would be better.. a magnum 52 xls would haul this nicely or should i beef it up to a 60 size 2stroke?

RE: Not a speed plane but....
 

with a Jett on the front, there are no buts

kc

RE: Not a speed plane but....
 

Wise-ass

RE: Not a speed plane but....
 

Razor you don't post in the Extreme Speed Prop forum if you're looking for pattern advice do ya?? [8D]

kc

RE: Not a speed plane but....
 

Magnum will turn up some R,s with small prop. run it rich on bench cause it will unload in air. Then put it in a dive to make it scream. Best of all you can buy two XLS 52,s for the price of a good 61. So you can afford to burn one up. I wonder what would happen if you took the cylinder out and took 10/1000,s of an inch out of the top of the exhast port to retime for higher RPM and smaller prop 9x9 or a pylon prop.

RE: Not a speed plane but....
 

you'd end up loosing power because your extended the exhaust duration doing so, unless you brazed the bottom up as well.

kc

RE: Not a speed plane but....
 

You could take the timing event numbers from any high performance engine and work them into a cheaper engine. Without starting out with high quality bearings, it is kind of a crap shoot. Raising the middle third of the exhaust port is a trick in favor with some C/L speed guys. You lose torque and gain revving ability......plus raising the port is SOP if you want high gains with a pipe. The carb is most likely restrictive if it allows a low idle, good throttle response....so open it up to match a like sized competition engines'. Lightening the piston and oval shaping the rod will reduce enough weight where rebalancing may be needed by removing some metal from the counterweight, but will really allow the parts to rev with less stress. On the piston you can raise the skirt that is on the boost port side, this will unshroud that passage [at BDC] as well as remove weight from the piston. Down inside the piston there is always dead weight to be found. By the time you're done doing all this and buying all the equipment to do it, you might have been better off just buying a competition engine, though.