Thermal coat on exhaust ports?

[JeffG]

Is it a worthwhile expense to thermal coat the exhaust ports on iron heads? Anyone have any experence with this (before and after)?

Thanks in advance,

 

[bruce]

Originally posted by JeffG
Is it a worthwhile expense to thermal coat the exhaust ports on iron heads? Anyone have any experence with this (before and after)?

First thing the exhaust ports need, is some bar stock cut, and driven into the EGR ports, and then ground down to form a decent port.

Then coat them.

Seems to have helped on one engine I did it on.

 

[JeffG]

Thanks Bruce. Heads are Champ Irons. The EGR port has been filled, but was drilled to maintain functionality (CA. smog).

I figured it would keep heat out of the cooling system and into the exhaust track where it's useful, but with a relatively short port I didn't know if it was worth while to do.

Thx again,

 

[bruce]

Originally posted by JeffG
I figured it would keep heat out of the cooling system and into the exhaust track where it's useful, but with a relatively short port I didn't know if it was worth while to do.

Most people miss the heat into the cooling system connection. I wonder in part if the holes are so extensive in order to speed up betting some heat into the motor on a cold start. If you watch the EGT, at a cold start, it only takes seconds for it to start reading signifigant temps..