Anything from RB will be outstanding, I have been racing their motors since 2002.

OS big blocks (of the V series) don't tend to last too long and have a trend of bearing and connecting rod failure. I used to race them until I found RB and now won't ever look back.

Novarossi P5x's have outstanding power and seem to require little in the way of tuning having raced against them a lot but I have never owned them. I seem to stay neck and neck with them on the straights though with my unmodded RB S72 so they do have good power but not to the point of uncontrollable.

I have no experience at all with the sirio motors other than what I have heard and it was rediculous power but not to great on reliability and tuning.





For cheap and fun, nothing beats an OS RG with a Nova head though.