RE: High power sport engine
Well, based on what I saw today, I'm not super impressed. Airraptors 46FX modified turned an APC 9x7 at 17,000rpm on the 3rd run on 5% nitro 20% oil. Ran my TT 46 pro right after and got 16,500rpm on the same prop, plug, and fuel. The TT hasn't run much this year, last summer I was getting 16,800rpm on the very same prop, plug, and fuel.
Considering the amount of work done to this engine to get this result, it's not worth doing IMO. I could make up the rpm difference with more nitro. I'm sure if I ran the dickens out of it I may have seen better results. Maybe.