I put heat in my motor ,about 170 to 180*'s about 30 - 45 mins before I run then let it cool. I've never had a motor that liked to run under 155ish so I always stage at 160 to 170. With that being said I will not stage until I get it back down to 180. It only takes a second or two to go from 185 to 200 in most race cars. I use to worry about mine when it hit 200-210+ on the return road, but have had to do it a lot. NASCAR motors run at 240*'s all the time, but I'm not going to let mine get near that hot.