I built a sbc 400, wanted to just re-use the current exhaust manifolds which were stock and the crate 350 that I pulled out. Shouldn't these old exhaust manifolds bolt right up to my new sbc heads? I can get 6 bolts of the eight started and nearly snugged, but the last two seem to be about 1/16-1/8" short! I tried moving, jiggling, starting at both ends but really don't know what to here. Any experience with this? Anyone?
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.
Sbc Exhaust Manifolds don't fit!
- Thread starter rman45
- Start date
Cornfield creations
1/2 ton status
Manifold shrank. You can try a manifold stretcher but they usually snap the manifold. I have drilled out the holes a little bit bigger on a set and played with it some and it worked out.
Ditto, they make a spreader, I haven't used one, but I've heard results are less than desired most of the time.
I have a manifold spreader and it only works for nudging the manifold very small amounts if it needs to be spread more than maybe .040-.050 the manifold is going to crack I can almost guarantee it!
The best thing to do is to like stated earlier by Mr Cornfield Creations is to drill out the holes a little larger. I keep a good sharp 1/2 inch drill bit around for just such occasions.(READ- every focking time I have to install a set of manifolds on a SBC) Yeah, its that big of a problem!
The best thing to do is to like stated earlier by Mr Cornfield Creations is to drill out the holes a little larger. I keep a good sharp 1/2 inch drill bit around for just such occasions.(READ- every focking time I have to install a set of manifolds on a SBC) Yeah, its that big of a problem!
Cornfield creations
1/2 ton status
Yeah when I ran into that the first time I also thought I was nuts. It's one of those mysteries.
I bought my manifolds form www.1aautomotive.com to replace the headers that were on my truck when I got it. They fit and had all the right holes for air pump and came with plugs in them you could take out. Paid $60 each from them and they sell on eBay for less than web site. eBay user page for them http://myworld.ebay.com/www.1aautomotive.com
only if you like you manifold MORE warped than it all ready is. I'm not kidding, I heated one up once trying to do just that and I watched it twist up a it cooled. Another $45.00 down the drain. The focking thing warped almost .125 right before my eyes. it wouldn't sit flat against a flat surface at all after that.
smalltruckbigcid
1/2 ton status
The trick is to bolt it on snug but not to tightly and then heat the inner part of the bend so you can slide the bolt in.
4xcrazy
3/4 ton status
the manifold spreader works just fine, i have used them before, start the two center bolts, install the spreader on one side, and spread until you can get the bolt in, in small increments.
you really won't need to spread them that much, once you get it on, you'll see.
you really won't need to spread them that much, once you get it on, you'll see.
Yes!
Hell yes!
FRIZZLEFRY
1/2 ton status
Heat the manifold cherry red where you want it to stretch when you use the spreaders and you wont break the manifold 
I usually need the spready and a good deal of heat. Crank the spreader slowly in small increments, and burn that inside bend/bends
Good thick gloves are nice!
Oh and most of the spreaders i have used are pretty crappy. buy two in case the first one won't survive long enough to do the second manifold.
Good thick gloves are nice!
Oh and most of the spreaders i have used are pretty crappy. buy two in case the first one won't survive long enough to do the second manifold.
