The Stovebolt Site Forums The Shop Area Engine Shop exhaust manifold 235

1954 chevy 3100 235. Tired of the exhaust leaks I pulled off the intake and exhaust manifolds. Though it might be nice to not fill the cab with poison gas every time i take her for a spin Found a pretty good exhaust man. at a local boneyard, at least its way better the the pitted one i had. Been looking around online and from time to time i see pics of 235's where they've replaced the two outer mounting studs with actual bolts to better pull the exhaust manifold in to the head. Thoughts and experiences?
Mark

Really dumb idea. The designers put those studs there for a good purpose. The end studs are there to allow the manifold to expand and shrink without warping or cracking. Have a machine shop mill the manifold or use a big belt sander to flatten the gasket surface, and leave the intake/exhaust connector bolts slightly loose until the assembly is firmly bolted to the head. A Remflex gasket is also a good idea. It's thicker and more durable than an OEM gasket.
Jerry

I'll second the Remflex suggestion, they are an outstanding product:

https://catalog.remflex.com/

thanks

Blackjack 54 That is such a good name for a truck ,a lot of them use the name of who it came from,My winch truck is Ed that way,nother one is Marion old farmer next door, thought I might try to letter some of that stuff on with like whitewash (lime and water) see if I could do it. Then if it bombed just wash it off ! Well spring is coming,need to get my 48 2-ton out and spread some gravel on this mud !

I put a bolt in the rearmost position on a Fenton setup with the engine out of the truck. Otherwise it's a three-hand job to mount the manifolds and gasket. I left the bolt in. A short while later, with the engine in place, I needed to remove the manifold to fix a leak and had to grind a 9/16 wrench specially to be able to nibble away at that bolt. It would be next to impossible if the bolt was rusted in place or if the head was mushroomed. What with the grinder time and nibble time it turned into an all afternoon job. I did not put the bolt back in.

My son named her Blackjack cause everytime you get in its a gamble so he sez

gotcha.. good info

Blackjack 54 Remember those tin things on the manifold bolts of like a small block 283 ?? They used those because of a low torque setting on especially the outer bolts so the manifold could scoot out when it got hot. Well when rodders came along and wound those to their limit it would blow the gaskets out,hence that age old problem exhaust leaks !!

I have no idea what tin things you mean, but I am intrigued. Any details or proper name I could use to do more research?

He's talking about the sheet metal locking tabs that were installed under the original small block exhaust manifold bolts. Once the bolt was torqued, a tab was bent up onto a bolt head flat, supposedly to keep the bolt from loosening up. They were worse than useless. Most of us who made a living wrenching on Chevy engines back then had a 9/16" deep socket with a bevel ground on the end so we could hammer it onto the exhaust bolts and release the locking tabs.
Jerry

Fibonachu It was a "U"shaped piece of metal that went on both bolts at the outer port of both ends of both manifolds. These then had tabs bent around the bolt heads of 8 bolts so they couldn't come loose. If you notice those bolt holes in the iron manifold are bigger than the bolt so it could expand when it gets hot.