Manifold gasket installation question

I pulled the manifolds because of an exhaust leak which I NOW think was caused by un-torqued bolts. I was expecting a fight but they came off really easy...too easy. But anyway, I have some new Crown brand gaskets and don't have any instructions about dressing. The last time I did some gaskets we used gasket shellac. What is the modern mechanic using in this case? BTW the engine is a I6 and the gaskets look like grey paper?? Any ideas?

Thanks

 

I have always been told to not use any kind of gasket sealer on exhaust manifolds or headers. just put it on metal, gasket, metal, and torque it down. see what others have to say about it.

 

ditto. use nothing.
If you use something, chances are it'll burn off the gasket and you'll be back to a leak. (don't ask me how I know).
Make sure the mating metal surfaces are clean, studs and bolt threads cleaned and lightly oiled.
You can take a file and dress up the manifold ports to insure they aren't warped. A sanding disc on the head cleans it up pretty.
A intake gasket should be put on plain, no "jelly" either.
The gray kinda paper ones are just a manfactors gasket material.
I've repalced a few headers that have used this materal, (most times they were metal or that metal with blue coating on them).
It's thick????? which is good as it'll compress to help seal it.
Install, fire it up warm it up, re torque the bolts
Joe
If it were easy, it wouldn't break!chainsawguy

 

Make sure to check the gasket where the intake and exhaust manifolds bolt together, I just had to replace mine to fix a leak. 72 with a 258.

 

Thanks for the info guy's. Thought that may be the case but it doesn't hurt to ask. No gasket goop will be used.

 

you will need to loosen if not remove the 4 bolts that hold the intake and exhaust manifolds together and tighten them after the ones on the head if not it WILL leak

 

Both manifolds are separated and I have the bolt tightening scheme from the manual so with the no goop info from the group and your info I'm pretty much good to go.

I do have a minor? challenge on the intake manifold. There is one mounting tab/loop that is broken so I don't have a full loop to bolt through. I think I have enough material on the body of the manifold to allow the bolt and washer to grab and tighten against the block. I wouldn't do this with the exhaust but I think it will fly with the intake. I think..hope.

The challenge



Ready to go

 

I initially used a Felpro manifold gasket ('72 with a 232). It is metal and thicker than the paper ones. I had to remove it at one point and bought a paper replacement (the only one that particualr FLAPS had in stock). It leaked -- IIRC it tore in a small spot during installation and I didn't notice at first. I got another Felpro metal gasket and it worked great. No leaks, easier to install. You can buy the Felpro version at any Advance Auto Parts.

 

Good info. I never liked the look of those "paper" gaskets but they must work for someone. I have more time than money so re installing them isn't that much of a big deal. But, I'll still look into the cost of Felpro set. I have an Advance nearby.

BTW, send those kids over here, I have lots of wire brushing for them

 

I think they are only $15.00 at Advance. Worth the extra $5 - $10....the gaskets, not the kids.....

 

Manifolds installed - observations

Installed the manifolds today and had a couple of interesting observations.

1- The gaskets I have include a metal center section with "paper" on the front and back. I opted to use them based on that and the fact the Advance Auto Parts didn't have any metal gaskets. I'll report on how they work.

2 - The broken loop on the intake manifold I was worried about turned out to be a non issue. That hole/loop indexes the manifold on the studs that are attached to the block. It is not a location where a bolt attaches the manifold to the block. Don't know why I missed that initially but there you have it. The manifold positions just fine as is.

I'll report on how the gaskets work once I have it fired up.

 

I actually about to do this exact same thing, I bought an entire gasket replacement set from Felpro and I like the look of them. Im even replacing the head gasket.

 

Was Advance just out of the Felpro gasket? I suppose it could have been Auto Zone that has them. My engine is out right now, so I'm going to need another one soon.

 

You realize that the factory did not use an exhaust gasket? The exhaust manifold was installed iron-to-iron. The composition doughnut gasket was replaced by an iron "gasket", and later manifolds had the sealing surface cast-in. The iron doughnut was available from Felpro - don't use a composition one.

Exhaust leaks at the head will erode the mating surfaces, and then you must use a gasket. Or else have the manifold surfaced at a machine shop.

AMC inline 6s are terribly prone to manifold leaks at the cylinder head. I suggest occasional tightening of the manifold bolts to the torque specs, especially in the few weeks after a new gasket.

A Remflex exhaust manifold gasket is another (high-dollar) option.

 

Thanks Tim ...That clear up alot for me too......I am on 4 composition donut..

 

I have heard that. But I've got an aluminum intake from a later model to fit my 2bbl carb and a relatively cheap header for the exaust. Therefore, the gasket.

 

Yes, you need an intake manifold gasket, regardless of iron or aluminum. Only the exhaust manifold was iron-to-iron. And the 4-bolt heat riser gasket is required in all apps with an iron intake. Fortunately the later aluminum manifold does away with the heat riser gasket.

 

Got it. That certainly makes sense. I just always think of the intake and exhaust gaskets on the I-6s as more-or-less one thing. They usually come together when you buy them. It makes sense that, regardless of the application, the intake manifold gasket is needed.