I'm using my OS32sx-h in my Gremelin combat plane. And I was wondering if the only difference between the sx and sx-h is just the bigger head for cooling and the location of the needle valve. If you know of any performance diff please let me know. I've heard there could be a porting difference is this true. Also when I run it up to full throttle with a 10x6 I'm only getting 7760 rpm this seems low. Any opinions

A 10X6 is a bit heavy for a .32. Try a 9X6, and you should see a large improvement. It might turn a 10X5... more likely a 10X4... we mostly use 10X6 on .40 engines.

I run a 10x6 MA an my .32 sx at 13000 RPM, I would have to say there is a prob somewhere.(15% fuel).

Not knowing about Heli engines I would guess that the SX H should be just as good as the SX. I tried different props, both APC and MAS. The engine seems to liike it better when it gets to rev up and it prefers MAS props. The best all around performance I obtained with 10% nitro was using a MAS 10-5 prop. Then I would consistantly get 14,200 rpm. If your only getting 7760 rpm something is really wrong!! I just can't guess what it might be from here! You aren't trying to use car fuel or something like that are you?![8D