Converting a heli engine into a plank engine....

A plane is never as picky on engine as a heli and when planks are lacking power, the usual approach is not to upgrade the engine to a more powerful one in the class like what heli flyers do. Instead, plankers either down size the plank or up size the engine, either way, it is FUN. As such, even a worn heli engine can make a good plank engine as long as the air frame is of the correct size....

While the heatsink on a heli engine does seem quite a lot bigger, I haven't really found a problem with it on a plane. No issue with cooling(or rather over-cooling) or c.g..

Converting a heli engine to spin a prop is VERY easy. All you need are...

1. A muffler for plane engine, not because the heli one doesn't work, but because it looks ugly with the lump hanging out in the wrong direction due to header direction. For my tt50, I used the tt46 muffler. NO fancy tuned pipe or tuned muffler is required. The cast iron two piece type muffler will work extremely well and is just 1/10 of what shiny heli mufflers cost...

This is how it looks like with a heli muffler...UGLY

This is how a plank muffler looks like on a plane...it goes toward the rear, while a heli exhuast faces sideway...
2. Unforunately, the crankshaft on a heli engine is much shorter, so its almost impossible to use a spinner, so what you need is a prop nut. Its nothing more than a mini spinner that is threaded and act as a stopper nut to secure the prop. Different thread size for different engine. There are two types of material, one being the standard type and the other is the brass type that is a lot heavier and will help a tail heavy plane. Some smaller prop nut like what I am using requires a different starter cone(the rubber piece), not a biggie though...

3. Drive washer set, each engine has its own type of drive washer, available at your LHS for just a few bucks. I believe its called the collet set or something along that line...in any case, as long as a shop stocks spare parts(rings, pistons...etc) for a engine, they will definately have a collect set or washer set for it.

All the stuff required...drive washer set, prop washer and prop nut...

Prop mounted