I've been using MVVS since iron curtain days and they are super engines in all respects! Their 2.5 diesel is a bit heavy but the .40, .49 range of engines are very powerful. Since they went to the rotatable cylinder ( so that you could decide where you want the exhaust to exit) I've heard of crankcase leakage problems due to the thin walls on the bypass ports, however I have not experienced this problem. I would give them 2 thumbs up!

Max