WhiteRook

My Feedback: (38)

i own a BGX 3500 THAT has some slight scoring on the piston , in the area of the exaust port,
the ring looks fine and the compression seems to be good, is there any cause for concern?

Bax

My Feedback: (11)

Maybe, maybe not. The scuffing you see is the result of lean running. The piston swells a bit at the hot spot and squeezes out any lubrication. The scuffing/scoring is hte result. If you don't do it again, then you may be able to live with it. If not, then the piston/cylinder fit will erode to the point that the engine won't run well at all.

WhiteRook

My Feedback: (38)

BAX they recomend 5% -10 percent nitro and 18% oil, what is the best fuel for these engines?
also, whats the best prop for this engine? and RPM, its going in a giant warbird.

THANKS

Bax

My Feedback: (11)

We'd suggest a 10% fuel with no less than 18% oil content. On the test stand, we use an APC 18 x 6 or 18 x 8 propeller, and expect the engine to turn about 8,000 RPM, plus or minus. The stock muffler is fairly restrictive, so other types will allow more RPM.

Any propeller that allows about 8,000 RPM when leaned to just rich of peak RPM on the ground, and flies your airplane the way you want, is the correct propeller. You match the prop to the engine to get the RPM you want, and then see how the model flies. Try different prop diameters and pitches that turn the same RPM and see how the model flies with them.

We don't have specific propeller recommendations for particular airplanes.

WhiteRook

My Feedback: (38)

thanks Bax