charles harbert wrote:

  H.P. Coatings in Oklahoma City

says they don't recommend internal coating because it don't last.
Question 1:  Who has experience with multilayer thermal coatings for 13B

applications and Question 2:  Has anyone got any info on internally
coating the exhaust manifold, especially with a turbo.

I've seen complete coatings (inside and outside) on exh manifolds, but I was
told not to do it (upstream of the turbo) because if a piece comes off, it could
destroy your turbo. Rotary exh temps run up to 1,700+ degF, especially with high
turbocharging. I used Inconel for the exhaust manifold, and thermo-coated the
exterior. For a NA engine, if you could get it to stay on internally that would
be ideal because there's a lot of heat to shield inside the cowls. I suspect
that p/o the problem is the different expansion rates for the metal manifold and
the ceramic coating.

Chuck somebody asked the name & phone # of your machinist that upgraded the Ross
gear box with a thrust bearing. Is he interested in doing a few more?

Paul Lamar

 
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