Engine Temperature
Safety Car
Joined: Jun 2001
Posts: 4,004
Likes: 2
From: Severna Park Md
Re: Engine Temperature Revised (jpatrick636)
The more power produced the more heat produced and the greater cooling capacity required. I would say around 180 degrees is a good op temp if you can keep it there. it all depends on the setup really. Some engines may do better hotter and some may do better cooler. But 180 is a good average.
Thread Starter
Drifting
Joined: Jul 2003
Posts: 1,253
Likes: 1
From: East China MI
Re: Engine Temperature Revised (Jvette73)
Thank you for the response. After installing a BeCool radiator with dual Spal Fans and Evens Coolant, I found I could control the temp all the way down to 165 as long as The air temp was not above 85. This led to wonder what was ideal.
Race Director
Joined: May 2000
Posts: 12,712
Likes: 2,270
Re: Engine Temperature Revised (jpatrick636)
Commercial gasoline contains about 19,000 BTU per pound, and a typical engine running WOT near the torque peak will convert about a third of this energy into useful work at the crankshaft. Of the remaining two-thirds about one-third goes out the exhaust and about one-third is dissipated by the cooling system. Of course, at idle, ALL the fuel's energy either goes out the exhaust or is dissipated in the cooling system, because the crankshaft is not doing any work.
The cooler the jacket temperature, the more energy the cooling system will remove and this is usually subtracted from work at the crankshaft, however, higher jacket temps can promote detonation, so somewhere there is a tradeoff, and it's typically about 200-210, but may be higher for aluminum engines.
It's also important to have a proper ignition map, which includes proper idle and part throttle advance, which means a vacuum advance that is properly matched to the engine's manifold vacuum characteristics. A proper ignition map for all engine operating conditions will minimize heat transfer to the cooling jacket without developing hot spots on the combustion chamber surfaces that can foster preigntion and detonation.
Duke
The cooler the jacket temperature, the more energy the cooling system will remove and this is usually subtracted from work at the crankshaft, however, higher jacket temps can promote detonation, so somewhere there is a tradeoff, and it's typically about 200-210, but may be higher for aluminum engines.
It's also important to have a proper ignition map, which includes proper idle and part throttle advance, which means a vacuum advance that is properly matched to the engine's manifold vacuum characteristics. A proper ignition map for all engine operating conditions will minimize heat transfer to the cooling jacket without developing hot spots on the combustion chamber surfaces that can foster preigntion and detonation.
Duke
