It's easy enough to figure out which engines are considered the "best", (just check their prices on Amain ((as a yard stick)) ) but you also need to keep in mind what you're looking for in the engine. It depends on where you'll be driving your buggy as well. Is it a huge track with long straights? Or is it small tight and technical? Maybe it's a medium sized track that you need and engine with good overall traits. These are factors to keep in mind when getting a new engine.

Top of the line engines include OS, RB Concepts, Novarossi, etc...I'm sure loads of people will throw more names into the list. Also keep in mind that you can send these engines off to get modified to even further enhance performance for what you want the engine to do.

Have fun man.