Ultima Overheating solution?

[karlo]

Following posts on the cooling issues of the Ultima I recently talked to drag racer/oval racer, that has $30k in his motor. The biggest reducing in heat for his engine was therma coating the exhaust ports on his alluminum heads. There was a 30f degree cooling effect!!! Cost $400 for the set. Coating the exhaust ports AND coating the headers made the performance and durability invaluable for him.

[greenv8s]

Coating inside the heads themselves? Didn't realize they did that. Does it make much difference compared to just doing the headers?

[davefiddes]

You can get lots of engine bits ceramic coated: the exhaust ports, intake ports, valves, heads and the piston tops.

Heat transfer is greatest where the temperature differential is greatest. Coating the parts of the combustion chamber stops bits of the engine from overheating. It also keeps the heat in the combusion process thereby increasing the pressure and thus power. One of the main reasons for coating the combusion chamber is to reduce localised hotspots that are causing detonation. In theory this allws you to run more aggressive ignition timing, higher compression and other good things...

[greenv8s]

davefiddes said:

One of the main reasons for coating the combusion chamber is to reduce localised hotspots that are causing detonation. In theory this allws you to run more aggressive ignition timing, higher compression and other good things...

Why doesn't that have the opposite effect? I would have expected the outer surface of the ceramic coating to end up a lot hotter than the bare surface of the head would have been? Or does it have time to cool between consecutive firings?

[BogBeast]

I asked a similar question a little while ago on this thread:

www.pistonheads.com/gassing/topic.asp?f=66&h=&t=20433