Debra
04-27-2007, 04:34 PM
I recently bought a Webra 91 engine with geared reduction unit.what I would like to know is what does this engine equal ?
Its new in the box and the engine has a slider carb.the carb has dynamix stamped on it. the engine crankshaft gear is 26 teeth and the lower reduction unit had 49.
I want to use this engine on some type of airplane , but have no idea what size airplane will take it. appreciate your in put on this engine.
I enjoy your engine clinic and your information is real handy. keep up the great work. --W.
Dear W,
With a 26 tooth drive gear and 49 tooth reduction gear this equates to a prop reduction ratio of 1.88:1, or not quite 2:1. With this reduction ratio the engine is going to turn a big prop at low rpm. As an example, if the engine
is turning 13,000, rpm which is the range in which most sport 2-strokes develop their best torque. the prop will be turning 6,915 rpm. Prop wise, I would have to guestimate something in the 16 x 8 - 10 range. This should, in turn, handle up to a 120 size aircraft in the 12 - 15 lb range.
Yours,
Clarence Lee
Its new in the box and the engine has a slider carb.the carb has dynamix stamped on it. the engine crankshaft gear is 26 teeth and the lower reduction unit had 49.
I want to use this engine on some type of airplane , but have no idea what size airplane will take it. appreciate your in put on this engine.
I enjoy your engine clinic and your information is real handy. keep up the great work. --W.
Dear W,
With a 26 tooth drive gear and 49 tooth reduction gear this equates to a prop reduction ratio of 1.88:1, or not quite 2:1. With this reduction ratio the engine is going to turn a big prop at low rpm. As an example, if the engine
is turning 13,000, rpm which is the range in which most sport 2-strokes develop their best torque. the prop will be turning 6,915 rpm. Prop wise, I would have to guestimate something in the 16 x 8 - 10 range. This should, in turn, handle up to a 120 size aircraft in the 12 - 15 lb range.
Yours,
Clarence Lee