Conversation Between DP-buggyboy and human213

I'm not sure how long it would last with stock valvetrain and a large carburetor. Once the valves float enough to contact the piston, the top of the valve stems will let go pretty quickly. From there, the valve will drop down into the combustion chamber and destroy the head and maybe the piston. I had that happen when I tried the stock FS52 springs. It didn't take long at all.

The new Alpha engines are better suited for high-RPM and high output though. They are short-stroke engines and the conrod is much beefier than the older Surpass engines. They have more cooling surface area too. The valve pockets and ports are also much smoother, so they should flow better.

For sustained running, I'm not sure you could get away with much over 15000 on a bigger 4 stroke. For use in an RC car though, my Alpha and even the old FS52 would get over 20000. That was using the 40C cam and valve springs/spring seats, a V-spec carburetor, and a pretty wide-open exhaust. I'm not thinking you could make any power over about 12000 with the stock airplane valvetrain and carburetor. It might rev that high, but the power would peak around 8000 to 10000.

Hmmm.. I think this is how I reply on this new RCTech.
The clutch I use for the GT2 is just an MIP GT2 clutch, and I install it backwards. Other than that, it just uses an 1/8 scale size clutch bell or GT2/nitro TC3 clutch bell. It seems pretty linear, but there's not much slip. You might be better off adapting a heli clutch though. I know they're much different than car clutches. If you're a machinist and have access to a lathe, it wouldn't be too hard to do.

As far as a straight-pipe exhaust for the Alpha 56, open header makes the most power. It's LOUD, but will run better wide-open. Less back-pressure makes more power when it's revved out.
-Damon