The Stovebolt Site Forums The Shop Area Engine Shop Heat valve in manifold

1953 gmc pickup 228 engine:
My heat valve seems to be loose on the inside of the manifold (it flutters around easily) and the outside (weight?) barely moves when I tap on it with a hammer. There seems to be lots of advice on how to free up the valve with lube or kerosene, but is there a way to tighten the valve to the rod on the inside so its movement is the same as the valve when it turns instead of the tongue piece fluttering around freely? Thanks!

You would need to remove the manifold and either install machine screws to hold the flap valve to the shaft and peen the ends of the screws to keep them from backing out, or tack-weld the flap to the shaft. Be sure to position the flap properly before securing it to the shaft- - - -it's going to be a one-time opportunity to get it right. I've fabricated flap valves and shafts from stainless steel for a long-term fix.
Jerry

Thank you, this is helpful!

If it is like my 235 the weight is threaded on the shaft as well as a pin . There are bushings we’re the shaft goes through the manifold and the flap inside the manifold is welded to the shaft.

I rebuilt this one on a 1949 GMC 228. It was stuck and with new bushings and a stainless steel shaft it worked as it should after being re-assembled. The photos will give you a good idea of what's going on inside the exhaust manifold.

Wow this is extremely helpful. Thank you for taking the time to add the pictures!

From the photos you can see that welding the flap onto the shaft is a one-way street. If for any reason you or someone else has to remove it, there will be bad words bouncing off the walls of the shop. The factory apparently had anticipated a repair and used screws or rivets.