I will tell you but in celsious. Use this calc to make the celsious into Farenait if you want: http://www.towerhobbies.com/help/convcalcs.html

For a good engine temp i should say above 110 and below 125, BUT a good frienf of mine said that it must be 125 for the engine to running better, i don't know. I have my engines in 110-120 and i'm very ok. Wait for others to tell you, but yes above 200 farenait is good, of course be down of 270