Twin H Exhaust Manifold Heat Exchange

Browniepetersen

I am taking my Twin H exhaust manifold in to be cleaned and repaired and wondered if I should remove the heat flapper from the manifold.  I know it is to send heat back into the manifold until the engine heats up then remains open.  So what advice do you have, do I remove it or do I keep it and why,.  My engine is built to beyond 7x engineering.

RichardD

Any car with headers doesn't have it.  That should tell you something. In old times, counter weights were tied open.

Match ports to the gasket while at it. 

Ol racer

FYI

If your in a warm climate remove baffle especially with your Perf Mod's as RichardD said Headers dont have any restriction.....Ive cut off the baffle and left the shaft......As for port matching, just the Intakes would be most beneficial for Street.
(If you really wanted to do imatch gasket with the motor assembled, you could pack the ports with oily rags, then blend the outer edges of Block slightly with a Die Grinder),...

Browniepetersen

Got the manifolds back Friday and I must admit that the new method of cleaning these with electrical and bead blasting sure makes them look good.  I have read quite a bit about the engineering behind the baffle, and considering that I plan to drive it year round and seven months of the year the temp drops below freezing, I think I will keep it there.  Have a few cracks that I will start welding up today.