RE: Wich Fuel to use?
Won't win any races using airplane fuel??? Would you like to see all my boat racing trophies? I raced Namba class A hydro, Class B hydro and Class A outboard. Used 15 to 20% nitro with 18% oil. Boat racing is just as demanding on engines as car racing. As a matter of fact, I even used a OS21VF-C in my A hydro. That is a CAR engine. We used them to eliminate the hassle of water cooling. With a tuned pipe they turned around 26,000. That was on AIRPLANE fuel as you call it.
Don't tell me that car racing is all that different from boats. Boats can be worse especially if you lost the water cooling. Or you blew off and had no load on the engine. With a tiny prop and tuned pipe response was almost instant. That's why we all ran RPM titanium rods.
Oh and I used those same Car engines in CARS using the same fuel. Worked just fine. I still have 4 of those engines new in the box. I bought them 8 to the case diestly from Japan