SpeedRacer,

I just checked my records and discovered that the new Rossi 240R60, which is the long strokewith 10mm carbhas tested at 13,400 rpm with the JS-90, APC 11x9 prop,and 5% Omega. This compares to 13,000 rpm for the older Rossi 60 short stroke and 8mm carbwith the same APC 11x9 prop and full length Mac pipe and header. Ialso tested the older Rossi the same day with the JS-90 and the same prop and got 12,500 rpm. For what it's worth, this prop is about 15 years old. I don't know if the current APC props are exactly the same.

You could pull the head on the Rossi and measure the bore and stroke to determine if the Rossi is short or long stroke. I recall SG selling rear exhaust 61's about two years ago but cannot recall for sure but I don't believe they were advertised as long stroke engines. The current 60 side exhaust engine is the 35R60E which is a short stroke engine with a bore of 23.9mm and stroke of 22mm.

You might try this in the air and see how it works. By the way, what is the name of the plane you are racing? It looks fast sitting on the ground. Keep us informed how this works if you try the 11x9.


Danny