Originally Posted by atr4tigers
How critical is engine temperature to optimum performance on any nitro engine? What should the temp be for an OS 12 on a hot summer day with ambient temp about 90 degrees?
I think a little too much is made of engine temperature. Most people will tell you that a .12 engine should run in the 230F-250F range.
You ask a good questions because outside temperatures and humidity play a large role in engine performance and temperature. Another factor is the glow plug that you are using (ie. #5 or #6 will be hotter than #7). Also gearing can be a factor (ie, short techinical tracks requiring torque vs. large open tracks requiring more top end)
All in all you will most likely see average to good performance from your engine when temperatures reach 230F-250F (assuming clutch and two speeds are set properly). However, I would recommend using the temperature only as a reference. If your engine is running 270F and it does not stall, lean bog and is still blowing smoke....let it rip. Tunning to temperature will most likley leave you frustrated and under powered.