Intake Manifold Gasket Replacement

[Xavier]

While I am doing a suspension upgrade, I am going to replace my intake manifold gasket because of a small oil leak I had since I purchased the engine. The small leak occurs right above the bell housing on the back of the manifold where the sealant is and drops on to the block in a small puddle.

Any suggestions any of you have when I replace this gasket? Any do's and don'ts besides the obvious? Immediately I noticed that the new gasket set came with cork gaskets for the area that leaked; one set of two pieces for the font of the manifold and the rear; but the engine builder used Permatex black sealant only. Why? Whats best.

351w with Edelbrock Performer RPM intake and Dart Pro One heads.

Thanks.

[blykins]

I prefer the cork gaskets. Some do, some don't.

If you install the cork gaskets correctly, you will never have any problems.

When you remove the intake, clean off all the gasket material, and put a new set of side gaskets on. Set the intake on dry and see what kind of gaps you have at the front and back.

If the block has been decked, the heads milled, and the intake is new, then you may have more of a gap there than cork can account for.

In that case, you can either have the intake milled, or use Permatex again.

If you have about .100" gap or thereabouts, do the following.

Clean the block with lacquer thinner. Get your cork gaskets, lay them on the block along with the side gaskets, and make sure they will all fit together neatly. You may have to trim the tabs a little on the cork.

If everything looks good, use weatherstrip adhesive on the block and on the cork. Smear a very light coat on the block and the cork and then let them dry. After dry, set the cork on the block and put some pressure on it with your fingers for about 30 seconds.

They will NOT move or squish out when you put the intake on.

Now put a dab of RTV on top of the cork on each end where it meets the cylinder head. Repeat for front cork and rear cork.

Lightly smear a little RTV around the water ports on the head and lay the side gaskets on. A trick I use is to use about 4 studs on the heads. This will allow you to keep the gaskets where they need to be and it will allow you to lower the intake to the block in exactly the right spot.

When you have placed the side gaskets on, smear a light coat of RTV around the water ports on the gasket.

Now set your intake down on the engine. If you didn't use studs, look down through the plenum and make sure the gaskets haven't shifted. If not, install your bolts and torque them down. Torque to spec, following the right sequence.

Another very good tip.....DON'T use Felpro Printoseal gaskets. They will leak eventually.

[Xavier]

Thanks for the tips Brent. Can you confirm?; Permatex Black, right?

[blykins]

Yes, you can also use a product called "Right Stuff". BTW, use sparingly. A little dab on the corners where the cork meets the heads is good...you just need a small bit to fill the crack and seal the joint. When you put some around the water ports, use a very light coat...almost like a coat of paint. People sometimes get carried away with RTV and it just looks messy...plus it increases the chance of some falling into the lifter galley or into the ports.