You are going to have to make so many changes to any engine you choose, other than a purpose built engine specifically made for a high altitude UAV, why even bother paying extra money for a model application engine that will have to be radically changed away from its intended purpose? You're just wasting money. Better to find a utility engine candidate and start from scratch with that. Doing this should lower the price considerably.

Other than a compression release for starting, why do you need compression control? Never heard of such a thing in a two-stroke utility engine.

Leave the turbo and super chargers alone. They are only good for competition where your displacement is limited by rules and you need to develop more horsepower. Other than that they are just toys that add multiple failure points and little horsepower increase for their weight and complexity. If you need more power, use a larger, more powerful, engine. It's cheaper and more reliable. Probably weighs about the same too.

Fuel injection would be a good thing, if controlled with the proper program riding in the computer. Beats the dickens out of carburation.


Ed Cregger