This thread is for everyone else but me to describe what conversion engine they would build if they had a clean slate and a reasonable amount of money to build it. The rule here is that you can only select one power adder to build it. That means you must limit your engine to using either a supercharger, a turbo charger, or a reduction drive of your choice, or nothing at all but the engine. It's your choice. Hypothetically we can shoot for 200 HP or thereabouts as I feel that most builders would be happy if they had a 200 HP certified engine fall from the sky and land under their Christmas Tree. Maybe that wasn't the best choice of words for an aviation site, but you get the idea. The rules are loosely applied except for using only one power adder. You can build more or less HP if it suits you . The idea here is what do you think is the best way to economically build a conversion engine. Would a turbo engine be a better choice than just a reduction drive and WHY? Does a supercharger work better than the other options, or suit a specific need or situation for you...and WHY? What do you think you could build it for$? Are smaller engines at higher power levels the way to go....and how best to get there. What do YOU think is the best setup? After this initial post, I promise that I personally will not participate in the thread and offer any second guessing. I just want to see if everyone agrees or why they see a different method as the best way to go When comparing the different ways to attain the power they desire.