Center of mass on an airframe
Has anyone tried to use a crankshaft extension, or machined a longer crank to mount the motor and move it back to centralize the center of mass? Or would the stress and vibration be too much for it or the airframe to take?
I once examined a fairly large P51 (might have been 1/4 scale) powered with a good size gasser, with the engine mounted well back in the fuselage, prop shaft fitted with a pulley wheel which drove a substantial belt (~ 1" wide) which drove a shaft which extended maybe 12" out to drive the prop. In other words, the engine was shifted back maybe 12" from where it would be with the prop fitted directly onto the engine prop shaft. The power transmission unit was a commercially manufactured product, with a nameplate on it (not a home-made device). I made a "mental note" of the mfr name, but can't find the note anymore. It was something like "Acme Power Transmission Products" located in Massachusetts.
The fuse was in the back of a pickup, and I never did find out who the builder/pilot was. I was curious as to how this rig was balanced and damped against vibration. The installation looked pretty solid. I would like to have seen it fly, but didn't happen. My recollection is that it was not a straight ratio, but speed reduced maybe 5/4 as a guess, which would have torqued a bigger prop.