Cracked intake

Jordan Bergsma · Jun 13, 2011

My 77's intake's gone and cracked on me. The manual says don't try weld or braze them, but i figure its worth a shot before I shell out $200. Will I hurt anything by welding it? I know to drill holes at either end of the crack and weld in short bursts to give it time to cool, but what is the reasoning behind the manual telling me not to weld it?
TIA!

Uploaded with ImageShack.us

Uploaded with ImageShack.us
Uploaded with ImageShack.us

Uploaded with ImageShack.us

chucksoliver77 · Jun 13, 2011

Jordan, why don't you grind it out a little and use jb weld on it? just an idea i had, chuck

Anonymous-0 · Jun 13, 2011

They don't recommend welding/brazing it because it could crack even worse if the proper procedure wasn't used. I think if it was preheated to the right temperature and really slow cooled, brazing would be the best option because there's no heat involved on the intake manifold. Wrapping it in a fire blanket or burrying(sp) it in dry sand would slow cool it. You could preheat it in the oven and put it back in to slow cool it if you didn't mind sleeping in the dog house for a few days. LoL The oven might not get hot enough to preheat it though. I'm sure there's lots of info on the internet or someone will recall the right preheat temperature.

Anonymous-0 · Jun 13, 2011

I might be wrong; but I don't think a crack in that area allows air to get in. I think it goes to an empty chamber. Someone please correct me if I'm wrong.

denny-o · Jun 14, 2011

Having just gone through a big weld project and having porosity problems, let me second the idea of V grinding the crack and using a filled epoxy, like JB Weld, to seal it...

super 55 · Jun 14, 2011

I have a 1948 Chevy two ton with a 235 engine in it. I tried to find a manifold without a crack in it and gave up. I bought a spray welder and fixed it with no problems. I took it into the local machine shop to have magnafluxed and there were no cracks. In fact they sent another fellow to me just to have it done on an old Oldsmobile manifold. I am not even a pro welder. If you have a shop around that does spray welding, I highly recommend it. I drilled holes at the end of the cracks, welded it, cooled it in a bucket of sand and then ground it smooth. I also used a needle peening tool to make it look like cast. Can hardly see the weld.
Spray weld pics

A.P. · Jun 15, 2011

You are correct. Unless there are other problems with the manifold or modifications, this should not be a problem. Just drill out the ends of the cracks (or not) to prevent it from cracking further.

Don-Wi · Jun 15, 2011

Ran our 1600 for years with a crack there before replacing it.

Donovan from Wisconsin

Mike Bock · Jun 16, 2011

you need to split the intake from the exhaust manifold ,good luck on them bolts ,and clean out rust dirt etc, that swelled up and cracked manifold from inside if tou put a plate between intake and exhaust manifold the crack will not hurt a thing

Cracked intake

Jordan Bergsma

Member

chucksoliver77

Well-known Member

Anonymous-0

Well-known Member

Anonymous-0

Well-known Member

denny-o

Member

super 55

Well-known Member

A.P.

Member

Don-Wi

Well-known Member

Mike Bock

Member

Similar threads