Bent manifold and best way to bend it back?
 

I've bent a manifold or two over time due to nasty wrecks and/or the pipe hanger coming loose. Basically, the two ends on the manifold are no longer parallel, so when the pipe is positioned as it should be in the car, the manifold is not squared up against the exhaust port like it should be.

I've been using a pair of screwdrivers to bend it back into shape, but I bet there's a better way to do it. Anyone?

*If my description is too vague, I'll draw a picture or something.

I've bent a pipe or two in my time. I use the freezer and water treatment. I fill my pipe up with water and cap the ends. Then leave the pipe in the freezer over night, in the morning as the water expands over night it pushes out the dents / bends and it's straight. Works like a charm.

Thanks for your reply, but this problem can't be fixed with the frozen water trick. I didn't explain the bent manifold very well. I made a quick illustration:

The Blue line represents a correct angle with the engine exhaust port.
The Red line represents the consequence of the bent manifold.
The Green line represents the chassis.

He's talkin about the header being outta shape...Not the pipe itself.


markr04...i use the ends of a pair of plyers with the rubber handle's and use the edge of the table to get them both sitting level...ive found some brands like to get out of shape A lot easier then other's. :nod:

And just for comparison sake, here's an illustration of a correct/non-bent manifold.

Rubber pliers handle... why didn't I think of that? That sounds a lot better than the screwdrivers I've been using. The screwdrivers have been putting bumps in the manifold, lol.

Thanks.

I have had it happed. Used 2 big 4 way gloplug wenches to do the same thing you did. Works like a charm and doesn't ding up the manifold at all. Actually they are a pretty nice tight fit in there!:nod:

Sounds like another good way.

I like to make how-to guides for these things. If I make one for this, I'll credit "Integra" and "JAMMINKRAZY" from RCTech.net.

When bending a header back there is a good chance for the metal to crimp or rip. here is something to try, i have done it this way before with okay success.

Fill the header with fine sand (silt if possible) really pack it in there. this will allow the volume to stay consistant. cap it off and bend it back using tools like a vise and clamping lever (not a hammer or other sudden pressure device) apply pressure in a smooth gradual way to bend it back. the chance for failure is always there when bending headers back but this eliminates more than other methods do.

hope this helps

interesting POV looper. :nod:

I watched two guys use heat and pliers. One would hold the manifold with pliers on each end. The other guy applied heat from a small butane torch to gradually heat the pipe while it was being straightened. Took several minutes, but it worked. The header was bent further than the illustration shows.

I fill the manifold with sand and heat it up, makes it easy.

I got the idea from a buddy that makes CORR trucks for a living. Apparently that's how they bend the tubing to make the chassis and cage.

I used two wooden dowels to bend mine. get them close to the same diameter as the header , you would be surprised at the ease and the amount of control you will have.I originally used this when I put a big block on my Revo.I had to open the radius a small bit so the expansion chamber would clear the side a bit.

I use a pair of knipex flat channel lock pliers to close the C & a big pair of transmission c ring pliers to open the c & a vice,torch & brass drift to change the plane or parallellizm if you like that word better.Great thing about the plier only method is you can do it in the car with pipe installed & get a perfect alignment for those cars that you cant install the pipe straight for one reason or another.Works fast & acurate on jammin & dynamite headers.Not so good on os,nova,rb headers as they tend to be somewhat fragile. I'm liking the pound sand & heat idea for the thin & especially square headers.