All engines run better above 200 degrees, at least anything made since the mid-1970's. People who insist on keeping an engine down below 180 or so don't understand that the parts are designed to have the correct running clearances above that point, and as long as the coolant doesn't boil THE ENGINE ISN'T OVERHEATING!
Engines made since the mid-1980's are intended to run a minimum of 195 degrees, since they were designed to run a thermostat that opens there. In traffic, an engine with a good radiator and a 195 degree stat will get up around 220 and stay there until the road speed increases. There's absolutely nothing wrong with running there as long as the temp doesn't go high enough to boil, 250 or so with a 15-lb. cap.
An old stovebolt with a 7-lb. cap needs to stay down around 180 or less, but a short time above 200 won't hurt anything. A 7-lb. cap will raise the boiling point to 225 degrees or so. That won't hurt a 235, or even a 216, as long as it doesn't stay there for an extended period of time.
Jerry
Last edited by Hotrod Lincoln; 08/26/2008 4:41 AM.
