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Exhaust manifolds: goop gaskets or dry?

dremu

dremu

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Stock manifolds, not headers. They come with the metalized gaskets; should I do Ultra Copper or something, or just put it together dry?

Also, I assume a little anti-sneeze on the bolts won't do any harm, and might help me down the line if they have to come off again.

And yes, I have an exhaust spreader from when I did another truck's manifolds.

-- A
 
I've always used dry for the stock metal perforated gaskets, and have had no issues. And agreed with the antisieze (very lite application), and retorque after a heat cycle or two.
 
I've been curious what would happen with just RTV. I've seen the orange stuff stand up for years, so I know it's up to handling the heat, no idea why it wouldn't seal. Normally manifolds don't have much in the way of sealing problems in the first place. Might want to lay them on a glass table tob or something and see if the mating surfaces are flat.

I agree with dry metal gaskets by themselves.

Can you comment if drilling out the two end holes of the manifold would leave enough metal? Without the spreader, just wonder if that would work. Spreader I would think would potentially cause problems later on, since the issue (shrinkage, like a frightened turtle) isn't actually resolved, the bolts are still seeing a side load applied on them.
 
Not ideal. Worked, but i'd use the spreader in a heartbeat.

We are talking 1/16-1/8" MAX here guys.
 
I installed my new factory manifolds with the metalized dry gaskets...no leaks..
 
RTV on exhaust is hack imo... that's what gaskets are made for..
 
My experience with the spreader has been that it just gives you enough room to get the bolt in straight, so you don't crossthread. I suppose that's a smidge of side load, but the stock bolts are stupidly long, likely for this very reason.

Dry it is then, and thank you Zim for the reminder on the torque check... I so rarely deal with the exhaust that I forget that the heat expansion/contraction has so much effect.

-- A
 
Seriously though, get some Remflex gaskets, and be done wiht it once and for all.

I HATE doing this repair, and my part store gaskets lasted about 1000 miles.
 
I use those stock style metallized/paper gaskets with my headers, no leaks from them either. Nice & cheap too. :D
 
I got the ones with the "ears" that hang on the bolts...they are fine...
 
would you use some of that dead soft copper or aluminum with OE manifolds? I like my aluminum ones on the headers....
 
On a factory manifold I always check for flatness and then NEVER use a gasket and NEVER have a leak. The minute you add a gasket to the mix is when you start having exhaust leaks with factory manifolds.
 
My factory manifolds said not to use gaskets, yet came with a set...go figure...
 
I've just bolted the exhaust manifolds on with NO gaskets--provided they aren't warped to hell,you dont need any--GM never put any there that I know of,I removed dozens of manifolds at the junkyard and never saw any with gaskets that hadn't been added after the vehicle was sold.....................I use anti-seize,but its more important to put a lot on the shanks of the bolts than the threads--the bolts always tend to seize where they pass thru the holes in the manifolds,not so much in the threads in the cylinder heads,and the heads will snap off them when you go to remove them...........................................................................................................................................................................................................We often had to use a torch to blow off the bolt heads and use a bar to pry the manifolds away from the head when removing an exhaust manifold off an old engine--many times the bolt heads were so rotted no wrench could grab them,and vise grips could not be used,the frame was in the way..so once we got the manifold away from the head as much as possible,we'd cut the shank off the bolts as close to the manifold ,then it was pretty wasy to remove the remains with vise grips...................................................................................................My friend replaces a lot of exhaust manifolds on later Ford trucks--yesterday he was doing a pair on a '99 Expadition,and they were so rotted he had to use bolt-out extractors on the few bolts that had any heads left on them,and then sawsall-ed the manifolds off --its amazing,that a sawsall will slice thru a cast iron manifold (and the bolts) like butter much easier than you'd think,its becoming his favorite way to get old ones off quickly without damaging other parts or having to use a torch...usually they are less than 1/8" thick by the time they start cracking and leaking....he uses no gaskets,after making sure the new or good used manifolds are flat.....he has done maybe 50 pairs this way the past year--his best "customer" in Meinekie,they refuse to work on anyones exhaust manifolds if they need replacing,or even just the studs!...and they call themselves an "exhaust shop"????.....
 
No gaskets baring good flatness like Scott said. Anti-seize yes, but I believe, and correct me if I'm wrong but don't they make hi-temp anti-seize? If so I would use that instead of regular anti-seize.
 
Yeah you are NOT suppose to use gaskets with factory manifolds. Its a machined surface to a machined surface. And I have to totally disagree with you on this Ryoken. Theres nothing wrong with a little high temp rtv or copper gasket maker. I use copper gasket maker if they are nice and perfect flat and high temp RTV if they are a little bit out or have pitting on the mating surface. If you apply the correct amount and post clean a little you wouldnt even know theres sealer on there.

Gaskets are for headers NOT exhaust manifolds.
 
I'll let you know how mine goes...since I put gaskets on factory manifolds...
 
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