Inlet manifold heat control question

[Nigel Bailey]

Well, I've got the manifolds off and split without breaking anything (so far)!  The plate in my exhaust manifold that directs exhaust gas under the inlet manifold has long since frozen in what looks like the closed position and there are various parts missing. As I live in a warm state in Australia, I was aiming to have this plate closed permanently anyway. My question is, judging by the picture, it almost looks as if some of the plate has been trimmed-shouldn't it close fully against the inside of the exhaust manifold? Or is this the normal closed position? So need to decide whether I should let sleeping dogs lie and leave as is, or weld a new plate in there that fully seals off the space. All suggestions welcome! Thanks,

                                                                                                                                                                                                                                                                              Nigel

PS exhaust manifold will be ceramic coated after clean up to (hopefully) reduce heat transfer around the carb/fuel lines/pump.

[greg g]

Looks like some fiddled with that before.  The horizontal position equals most direct exhaust Flo with no deflection to the intake heat chamber.  On mine, I removed the flap, cut the shaft, brazed the holes closed.  Upon re assembly, I fitted a piece of thin stainless sheet stock and closed off the path to the intake. I am just starting to get a little past of an exhaust leak from some where in the area but I got 45000 miles on it before it started.  I run my car late into the fall when the weather gets below freezing. Never noticed any problems in drivability.  I do have my heater return line zip tied to the intake manifold but the heater needs to be on for it to make much difference.  

 

When you reassemble loosley again don't overtighten  put the manifolds together then snug up the fasteners for the manifolds to the block connection, don't overtighten.  Then finish up by securing the four bolts that hold the manifolds together. Again don't over tighten.  When you get a few heat cycles on the assembly you can go around and snug up any that need attention..  I think the torque spec is in inch pounds to allow for some movement as things he's and cóol.

 

 

 

 

 

 

[Sam Buchanan]

I removed the entire mechanism, plugged the holes, and installed a stainless steel block-off plate between the manifolds. Here is the method I used to plug the holes where the shaft used to be. I think it was a 5/16" bolt that was a good fit in the holes.

 

Edited January 27, 2021 by Sam Buchanan

[Nigel Bailey]

Thanks guys-much appreciated! Cheers,

                                                           Nigel