The Stovebolt Site Forums The Shop Area Engine Shop 235 Exhaust Manifold

I'm tearing the head off my '62 235 (burnt valve). While I have it apart, I thought I may as well change out the cracked exhaust manifold.

I've heard you should change out the intake along with the exhaust manifold so that you end up with a paired set to help prevent future exhaust manifold cracking.

Advice would be much appreciated. Thanks!

Glen

what i did, was have the manifold mating surfaces machined flat and used new gaskets. you also have to tickle the manifolds into place. this system worked for me and left no leaks.

True, the gaskets can be a little forgiving if the manifold mating surfaces aren't square.
I think the problem you could have, is if your old manifolds have been remachined at some point.
A remachined intake with a fresh new exhaust may be difficult to fit as a set since they fit in two places... against the head in one vertical plane, and to each other in a horizontal plane.
If you tightened the bolts to the head first, you may have a gap in the horizontal. When you torque those bolts, you would then be putting stress on the castings. This could eventually cause a failure... like a cracked manifold.
From this, I can see why it might be preferred to replace both parts.
I liked the "tickling" term. It means to me, that you tighten gradually, the vertical plane and the horizontal plane similar to the bolts on a head... in a type of sequence. Then at least, you'd be averaging the unsquare error to both planes.
You'd still have stress on the castings though.
If it were in my budget and to insure I had no problems, I reckon I'd replace both parts with new.
Just thoughts...
Jerry

Thanks guys. I'm half contemplating just living with the noise. Wrecker here wants $200 for one.

Pick up the used one, put it on, don't tighten it up, not all the way just enough to get the Intake and Exhaust both close then tighten the two together, take them off still attached together (Tight so they can't move) and to the machinist and have him plane them down together...

I like that idea. Thanks! (If I can find one for under $200!)

Try posting an ad in the "parts wanted" section of the forum.
https://www.stovebolt.com/ubbthreads/ubbthreads.php?ubb=postlist&Board=17&page=1
I have had good luck there

depending on where and how bad the crack is you could have it repaired by having it spray welded. i have had a few things repaired that way with success.