Installing Headers CORRECTLY

[JoJoBDA]

well, today i finally get my truck back, engine and tranny rebuilt, blah blah, new duel flowmasters and headers blah blah blah, all excited to get it back blah blah. the dayum headers are leaking right at the gasket and engine. the guy said they are some cheap gaskets and to brong it back to him, he has proven to be a shady man the whole time he did the rebuild and im doubting his excuse of "they are cheap gaskets" is there any correct or special way to put the gaskets on? any special tips needed? im pretty pissed about it because i wasnt expecting that at all. any response or info is greatly appreciated.

p.s.

A shout out to all the shady mechanics who keep saying for 2 weeks that they have the engine in their posession and they dont.... Screw You :-) and have a great day :-)

[Velcro]

"Cheap" gaskets generally seal for a short time and leak afterwards.
Not knowing all the facts here, I'd guess that the headers weren't checked for WARPAGE first. And if they were, it was "assumed" the gaskets would compress enough to compensate, and they didn't.
This would be similar to overhauling an engine without mic-ing the cylinder walls. Tapers or out-of-round will still blow oil, even with new rings. The cylinders would have to be bored and filled with oversized rings.
I hope someone else here can help you beyond this.

[LEVE]

If the gasket is good (and it can be) then the header may not have been installed correctly. The header bolts should have been tightened down in at least three torque sequences. Then the last sequence is followed up to make sure the bolts are all a the correct torque value.

Then the engine is run. I would not recommend idle, but actually running the engine out on the road to heat up the engine/header. Turn off the engine, and with the headers still hot... re-torque the bolts.

Then let the engine cool and recheck the header bolt torque.

Now you're ready to go and get a root-beer float for your troubles.

Then, after you've driven 75 - 100 miles, recheck the torque values to insure that the job has been done right.

It's almost over.

After you've drive about 300 miles since the install, recheck the torque value on the header bolts.

OK, if the header bolts are still torqued correctly, then you're done.

[Speed Dragon]

Are they new headers? I have a set of old ones on mine, they are a real PITA to tighten down, have to do it a little at a time on each bolt, and they still always seem to leak a little. I had them sealed pretty good one time, I used one-piece Felpro exhaust gaskets and red hi-temp silicone.

[vestpuzzle1]

Speed Dragon's right. I also used silicone. Worked like a dream....R.V.

[bherder]

Did the mechanic use the exhaust gaskets that came with engine gasket set? Or did he use header gaskets? There is a difference. If he used the 'stock' gaskets (As in what you would use for a cast exhaust manifold) they'll burn up and leak with headers in short order.
You might want to put a set of the thickest header gaskets you can find on your engine ("Mr. Gasket" for example) and as others said be very careful and do the proper steps when torquing the bolts up.

[vestpuzzle1]

If they are warped can they still be torqued up? (be used)

[Velcro]

If they're actually warped, a good automotive machine shop can mill them for you.

[LEVE]

If they are warped can they still be torqued up? (be used)If they're warped, they may, or may not be able to be torqued and work. It's a crap-shoot.


As vestpuzzle1 said, you can remove them and have 'em faced and trued at a machine shop.

With headers, warping/cracking is a huge problem as the metal is often thinner than cast manifolds and is subject to the same thing an OEM manifold is subject to, rust, expansion/contraction and vibration.

IMHO, I'm amazed headers last as long as they do.

[bherder]

If they're warped, they may, or may not be able to be torqued and work. It's a crap-shoot.


As vestpuzzle1 said, you can remove them and have 'em faced and trued at a machine shop.

With headers, warping/cracking is a huge problem as the metal is often thinner than cast manifolds and is subject to the same thing an OEM manifold is subject to, rust, expansion/contraction and vibration.

IMHO, I'm amazed headers last as long as they do.

"IMHO, I'm amazed headers last as long as they do."

Heh heh heh.... Man, ain't THAT the truth!! ;)

Vest... I'm gonna guess (So far as if they're warped) it depends on how warped is 'warped'...
This is my own personal experience... so take it for what it's worth.

At one time I had a 69' Roadrunner. Installed a set of brand new Hedman headers. Used header gaskets. After a month or so, started getting a couple of leaks. Replaced gaskets. After a month or so, again, a couple of leaks. Same spots.
OK, now I'm thinking WTF is going on here? Pulled the headers back out. I noticed that on the offending cylinders there was a little bit of 'spatter' from the welds on the mating surface to the exhaust ports. Got out a file and smoothed them all down clean and flat. Put everything back together. New gaskets and such. Lasted about 3 months and started getting leaks elsewhere....ARRRRRGH!!!!
So the guy at the local 'Speed Shop' tells me that the mating surfaces of the headers I bought (Which were 'econo' headers at the time) either were not perfectly flat to begin with or may have warped a little. The GOOD thing however was that headers DO have a little bit of flexability to them. He suggested that I double up on the gaskets (As in 2 gaskets per bank) and try again, and of course torquing from the center out as you would anything else. Bingo. Never had a prob after that until the day I sold it.

Since then, I've installed headers on ... Oh... Six other rigs I've had (Always new headers) ... Went across the mating surfaces with either a file or a very soft hand with an 8" grinder/polisher.... Put the THICKEST gaskets on I could find (Never used what came with the headers) and didn't have a problem ever.

EXCEPT.....

My 74' Duster (340).... Where the header pipes wrapped ALL around the starter... (Hooker headers if I remember correctly) ... There was so much heat it literally kept cooking the starter to death. I finally cured that by wrapping asbestos gasket paper (Ha! Try and buy THAT nowdays!) around the starter and holding it on with a big hoseclamp.... No probs after that....
But those headers never leaked though :D :D :D

[farmguy]

.....another vote here, for the hi-temp silicone....Had good results with it. It will take up the differences between the headers and the head.

[JoJoBDA]

well guys thanx a million, i drove the truck to where i baught the headers and showed the setup to them and he instatly said that the headers were not warped but instead they had a set of standard manifold gaskets on them, they r skinny as hell. i have to wait until tuseday to get the mr. gaskets. would this leaking cause the truck to stall at some cruising points? i am not driving the truck hard or anything, im really taking my time driving.

[vestpuzzle1]

Next time I have a problem with gaskets sealing, I'm going to double up on them and try that out......R.V.

[vestpuzzle1]

well guys thanx a million, i drove the truck to where i baught the headers and showed the setup to them and he instatly said that the headers were not warped but instead they had a set of standard manifold gaskets on them, they r skinny as hell. i have to wait until tuseday to get the mr. gaskets. would this leaking cause the truck to stall at some cruising points? i am not driving the truck hard or anything, im really taking my time driving.

U should be O.K., it's probably making some taping noises? That should be all it does. But don't quote me on that 'cause wierd s*** happens!....R.V. ;)

[Speed Dragon]

The brand of headers has a lot to do with it too I think. Cheap ones almost always have problems. Good ones, like Hooker or Hedman, usually work/last longer. Also, when you buy headers, get the thickest flange available, that helps keep them from warping.