How to screw up a Intake Manifold Gasket Install

[Clois Harlan]

Have you ever screwed up the installation of your intake manifold gaskets? If you have it was probably the end pieces, right? Well, I put my 3-M adhesive on my gasket instead of my heads and managed to let my adhesive dry too fast that I put around my water ports on my heads and my intake manifold gasket. So, I put a little more on there and things went from bad to worse. I guess I got the adhesive uneven on the gasket and when I bolted my intake down the excess adhesive allowed a vein for the water to travel into my exhaust port. When I fired it up my pipes looked like a steam engine. Naturally, I shut it down immediately and tonight I will pull my intake off and do the job rignt.

For those of you that my wonder why I use 3-M while I am using Fel-Pro gaskets that have a blue silicone sealant on the intake side of the gasket. It is because if you use a sealant like 3-M it will hold your gasket in place while you are positioning your manifold. I think I wll use the spray on copper gasket sealant when I install the next set of gaskets. Unless someone here can give me a good reason not to.


Clois

[Chaplin]

Clois-
I usually use permatex (either hardening or non-hardening, depending on the gasket) to hold gaskets in place and it works great. Haven't tried the spray on copper gasket sealant, so I can't give you any insight on that.

[CJ428CJ]

Clois,

I use Gasga-Cinch that I bought at my local Napa store to secure the gasket to the heads. I also use a really thin coat of silicon around the water jackets.

Chris

[PatBuckley]

Clois-

I wouldn't recommend using any gasket.

1) Put the side gaskets on then lower the manifold onto the block. See how much of a gap there is between the manifold and the block front and rear. This will let you know how much RTV you will need to put on the block so it will seal.

2) Clean all surfaces thoroughly.

3) Scratch up the front and rear surfaces with some 80 grit paper - do the block and the head.

4) Smear a thin coating of RTV on the intake and block surfaces - let it dry.

5) Build up a layer of RTV on the block that is higher than the gap you found in step 1.

6) Lower the intake into place - a second (trusted to follow directions) pair of hands is helpful.

7) Torque to spec.

I have never had a leak doing this. I have had leaks w/using gaskets.

Using an old ditributor as a locating guide for the manifold also helps - just cut the top off. It also makes a good "bushing" for priming for oil pressure.

Pat

[chuckbrandt]

I'm probably going to get flamed for this, but I've heard bad things about those gaskets deforming over time and giving you all kinds of problems.

I've been told to use Victor Reinz - 95159SG (medium riser) or 95158SG for CJ style heads. NAPA carries them.


Chuck

[Morris]

Clois

The only thing I would add to Pat's instructions is....

Put some RTV on your finger and force it in the corners of the motor where the block and head and intake meet.... that little junction is a natural place for a oil leak.......

BTW they make a Hi-Temp Clear RTV for this application.

Morris

[Clois Harlan]

I remembered to put the silicone in the corners and I did use Fel-Pro 1247 gaskets but I may try the Victor gaskets (especially since they are hlaf the price of Fel-Pro. However, I think I may pressure up my radiator (to about 18 lbs) and pull my valve covers off and see if I can tell exactly where my leak is coming from.

Clois

[John 550]

I too was told to use Victor Reinz -" nitroseal " (carbon grafite).
I was told that these will hold up where others will fail .
$30 bucks from Napa

[DC COBRA]

CLOIS
I am fairly familiar with FE style of engine, just curious, how do you get a water vien to feed an exhaust port from intake side? You might have a different kind of problem going on there.

DON

[Clois Harlan]

DC,

Not sure but I am checking everything. Couldn't see any problems w/ Edelbrock heads or block when I replace head gaskets. I am checking to see if the new manifold I replaced my 2X4 manifold with is not warped or pitted. This is a new problem I experienced since I swapped manifolds. I pressured up my radiator last night to see if I could spot a leak somewhere but I couldn't. Since there is no water in my oil I am wondering if maybe the end of my manifold may be warped so that I am sucking water into my exhaust port. I really don't know what to look for to be honest. But I will finish the tear down tonight and re-examine everything.

Just love a good mystery!!!!!

[Woodz428]

I too am wondering how water got from the intake side to the exhaust.The only lead to the exhaust is the heat riser passage and it is on the other side of an intake port from the water passage. Is it possible, since no water appears in the oil, that some coolant was introduced on the removal of the intake and is just burning out? Antifreeze steams at a higher temp and if introduced into the exhaust can take several minutes to get to temp and burn out completely. I'm curious to see how this plays out. I guess it could be seeping into one of the end intake ports and steaming in the combustion process, a plug reading would show that.

[DC COBRA]

Clois
If this problem started with a new manifold installation, go back and check everything from that point on. Just because it is new doesn't mean it aint broken. Definately would do a plug check, possibly when ever it was running was it missing, whichever side the steam was coming out of exhaust would be a good place to start checking that bank of cylinders. I have had seen problems of intake gaskets leaking water into an intake port before, usually you can tell, motor will miss, not sound right. Good news if any, no water in oil , therefore the problem really should not be hard to locate.

DON

[Clois Harlan]

After disassembling everything on the top end of the engine again and finding NO SIGNS of water migration from the water ports to anywhere. It dawned on me to check and see if my side pipe still had water in it, and it did. I am guessing about a quart. After replacing my head gaskets the first time I thought there should not be anymore steam produced by my engine and there wouldn't have been had I drained the water out of my muffler or removed my side pipes when I started the engine. Boy am I a dumb ass sometimes. I guess I just like to take things apart and defend my Cobra being on jacks all winter to my wife.

Now here is my latest question. Should I drill a small hole in my side pipe (in an inconspicuous (sp) area) to drain the water out and then have it tigged up. Or, should I bolt everything back up and boil the water out? My side pipes are 4 years old and blueing and will be replaced next year.

Thanks for everyones help in this. By the way did this play out the way you expected it to Woodz and D.C.?

Clois

[Woodz428]

That was kinda what I suspected. I would go ahead and burn it out. You'll need to take it on the road to get a good enough pressure and heat to get them clean. It will clean out though and steam like an old locomotive for awhile, but won't do any damage.If you don't want anyone to see your Cobra fogging the place, you could do it at night . Because of the slower steam rate of water/antifreeze mix, you might think it will never clean out, it will though and may even take come other carbon build up with it.

[Michael C Henry]

After having the intake milled to match the heads there wasn't much room for the original front and rear cork gaskets.Valve cover rim should be the same height. ports should match and carfully peen the gasket between the head and intake.Oil resistant RTV works great and no corner gaps.

[Bruce Edwards]

Clois,

I use nothing but FelPro gaskets in the engines I build and you never put any sealer on the gasket type you are using. The surface is coated so that the gasket can move around a bit as the engine heats up and cools down. You should need no other sealer of any kind on the intake to gasket or gasket to head surface. Only a very SMALL drop of sealer in the corners is all you need.
Silicone comes apart with fuel. It is not to be used for the intake side or any area were it can come in contact with fuel. Read the tube guys as well as the instructions that come with the gasket set.
If heads were milled and you milled the top of the block and intake to match the amount you took of the heads the gasket should fit just like it did before you milled it. If it does not something is wrong.
The intake gasket is made to hold in place by sitting on the head gasket tabs. That is why they are there.
Trust me on this. I can not tell you how many "Hotrods" engines I get in from folks that install intakes and then wonder why it runs so bad. After they have played with plugs, wires, carbs and the like they take it to someone that understands how it all works and the first thing to do is check the last thing they did before the problem.
Check the intake, Sealer leaking out the side every were. Pull the intake. Clean all the crap out of the ports and out of the bolt holes were it can give you a false reading on touqe. Put on a fresh gasket the RIGHT way and the problem goes away.