Ok heres the kicker , i took my venture cp 30 , and i put a 51 os in it , yes i did . had to do some mod`s on it to make it fit , got it in , running ok , but im running hot, im 1 1/2 clicks out and its ok in a hover but when i 3d then its starts getting hot. and 2 turns out to rich for a hover , i havent found my proper setting yet now i havent broke it in all the way. and i dont want to keep the engin hot breaking it in that way.Yes i know the fan shroud is only for a 30 and im running cool power 30% .
I was wondering if they sell a Mod Head on the 51 OS that is bigger and help it cool better?
And any advice on breaking in an engine , i been hovering on a half of a gallon of nitro , but man i get bord :0) then bring on the 3D, but on my other engine i was told just run it rich and fly it .

thanks for the help.

What is your head speed?

i have no clue about that, since im new into heli's i herd theres like some way to find out but ... I have no clue. im sure you can tell me how to check it? :0) what do i need my head speed at ?

If your over reving the engine that will heat it up fast, you can use a MA skytach. I don't know the gearing of that heli but 1650-1700 would be a good range. The high nitro will keep that engine running hot also, if you stick with the 30% try running the high speed needle much richer say 2- 2 1/2. At that setting the engine will heat up but wont go lean.

My best recommendation is to put a 32-39 size engine in since that is what the heli was designed for.