[bhieb]

This thread is very timely. I'm having my 421 tripower rebuilt and I'm looking for a way to prevent engine paint from burning off the exhaust crossover part of the intake manifold. It seems one way to do that Is to block off the exhaust crossover port, which I presume also means removing the heat riser valve from he exhaust manifold?

But is there another way? For example, has anyone had success using specialized paint, like the high temp version of POR-15 (https://por15.com/products/high-temp) perhaps as a primer, and then covering this base coat with regular engine paint? The high temp POR-15 is supposed to tolerate up to 1200 F. Anyone know how hot the exhaust crossover gets?

Brad

[Schurkey]

Originally Posted by bhieb

I'm looking for a way to prevent engine paint from burning off the exhaust crossover part of the intake manifold. It seems one way to do that Is to block off the exhaust crossover port, which I presume also means removing the heat riser valve from he exhaust manifold?

Yup, the heat riser has to be disabled if you block the exhaust crossover through the intake manifold.

Therefore, at best you'll need choke adjustment to make-up for the lack of heat on the bimetallic coil.

Originally Posted by bhieb

has anyone had success using specialized paint, like the high temp version of POR-15 (https://por15.com/products/high-temp) perhaps as a primer, and then covering this base coat with regular engine paint? The high temp POR-15 is supposed to tolerate up to 1200 F. Anyone know how hot the exhaust crossover gets?

I'd be surprised if 1200 degree paint will be sufficient under heavy throttle without blocking the crossover.