Intake Manifold Swap Questions...UPDATE 7/27

[Ponch ®]

Yep...here I go again. The reason my charger has been sitting for 3 years is because of an intake manifold swap gone wrong. Now I have a "new" 360 engine and instead of leaving it alone, im gonna swap the 2bbl intake for a 4 barrel. I never learn, do i?

Anyway...my first question is, do I need to use the gaskets in the front and the back of the intake, or should I just use silicon sealer?

[firefighter3931]

Leave it alone or it'll be down for another 3 years 

Use the gaskets AND sealer. Let the rtv set up before tightening everything down to spec. I would just snug things up then torque it down the next morning. A little dab in the corners wouldn't hurt either. 

Good luck Ponch 


Ron

[grouseman]

Use the end seals, but be VERY careful when putting the intake down as they can slide around easily.  Glue them down first and wait until they're 'set' fairly firmly.  Dab the corners, yes. 

[dodge freak]

I didn't know anybody that still used those end seals, so thats why they still come with the gasket. Silicone works just fine for me.

[Chryco Psycho]

I have done it both ways & both work

[BigBlockSam]

A little dab in the corners wouldn't hurt either. 

[694spdRT]

Whoever put the Eddy intake on the 318 in my Challenger just used blue RTV without the gaskets and it is leaking oil like a sieve out the back. Could just be a poor install.

[dodge freak]

On the small block motors Milodon and maybe others make a valley tray that goes under the manifold to keep the oil off the hot cross over pass. if used. Helps stops leaks also. Just $25 bucks o so. You have to remove the pushrods, then it drops right in. A good thing to add to those motor.

[Ponch ®]

so for reasons beyond my control, i wasnt able to do it after I posted this thread. I'm gonna do it tomorrow though.

1) whats the best kind of sealant to use (black, red, blue)?

2) when applying the sealant to the gaskets, is it better to spread it all over the gasket, or just apply a bead of sealant around the ports? If its better to spread it, how thick?

[greenpigs]

The intake gaskets should be installed as is & the ends I would use the black silicone.

[Ponch ®]

The intake gaskets should be installed as is & the ends I would use the black silicone.

no 'pamela' on the gaskets, heads, or intake at all? hmmmm...maybe thats what I was doing wrong all along.

[dodge freak]

I use a spray call Hi-Tack on the fel-pro gaskets on the back side that goes to the head, intake side I leave dry, works fine and if the intake needs to come off soon you can reuse the gasket if it looks good.

[Ponch ®]

I use a spray call Hi-Tack on the fel-pro gaskets on the back side that goes to the head, intake side I leave dry, works fine and if the intake needs to come off soon you can reuse the gasket if it looks good.

I take it the spray is some sort of adhesive that keeps the gasket in place during installation?

[dodge freak]

Yes , its not silicone-that breaks up with gas on it, and the intake has lots of gas going by it, like 20 gallons 1 or 2 weeks. Edelbrock has something also called-Gasgacinch but my can only saids oil , pressure , shock and water proof, nothing about gas. Hi - tack is made by Permatex been around for 40 years , looks red comes in a can or spray, you don't need much, its very sticky and messy. For the aluminum intakes use Fel - Pro Printoseal has a seal on the intake side , thats why I leave that dry. Some people like to use silicone on the water ports but then you can't reuse the gasket and its not needed. When you blot the intake down just go slow, 5 lbs on all bolts, then 10 lbs on all, then 15 lbs , up to 25 lbs or so. Some shop books have a patten you should go but I just go on one side then the other then back to the other side. Make sure everything is clean, use brake cleaner , not paint thinner . It should be fine. Good Luck

[Ponch ®]

ummmm....so the intake wont fit. It's entirely possible that i might be doing it wrong, but I cant get it to sit properly and have the holes for the bolts line up properly.

[dodge freak]

You either have a wrong one or the heads, block have been milled, if its the heads the intake side should have been done also. How much is it off ?

[Ponch ®]

You either have a wrong one or the heads, block have been milled, if its the heads the intake side should have been done also. How much is it off ?

by way of background, I had the same exact problem with the same intake when i tried to put it in my 318 a few years ago. Its a practically brand new edelbrock performer.

hard to tell how by how much the holes are off. However, with one side of the intake bolted in, theres about a 1/8 of an inch gap on the other side between the intake and the head (w/ gaskets).

[dodge freak]

Boy it sounds like something been milled. Not sure if you can use 2 gaskets, but it won't last more than a few weeks I would think. I never had this problem, maybe somebody else knows something. I did have a manifold that somebody drilled the holes bigger, maybe thats why they drill the holes bigger.

[greenpigs]

Damn Mojo you got rotton luck!

Take your gaskets and put the 2bbl intake back on, then get a 500cfm holly 2bbl and call it done.

[Ponch ®]

Damn Mojo you got rotton luck!

Take your gaskets and put the 2bbl intake back on, then get a 500cfm holly 2bbl and call it done.

that is always an option.

still, im not giving up on it so soon. the reason i never got the 318 running was because it was old and i figured it wasnt worth going through all the trouble just to have something else go wrong and wanted a new engine. For the 'new' 360 though, im willing to get the edelbrock intake redone to match the heads. The problem will be figuring out how much it needs to be redone. I reckon I could take the two intakes (the one that came off the engine and the eddy) to a machine shop and maybe they can figure it out by comparing them or something (if that is possible). Otherwise, yep...the 2bbl intake is going back on. 

for what its worth, its not like removing the old intake was a complete waste of time. I kinda sorta needed to take it off anyway to fish out a washer that I sorta kinda dropped into the plenum and went down into the heads when I was moving it around. 

[dodge freak]

Yeah-take both intakes to a machine shop-a good shop guy will tell you the right way to go. That 2 gasket deal is too easy to work right I am afraid. Good Luck.

[firefighter3931]

However, with one side of the intake bolted in, theres about a 1/8 of an inch gap on the other side between the intake and the head (w/ gaskets).

There are 2 possibilities here;

(1) The manifold has been milled to fit another motor which had some decking/milling

(2) The manifold was defective from the get go.


If your block and/or heads were shaved the manifold would be too tall (not too short) and it would sit on the heads but the boltholes would not line up. This is not the case and from what you're describing....the manifold is the problem. My guess is that this was a used manifold that was modified to fit someone else's motor...


Look on e-bay for an old edelbrock LD4B intake....those work very well on a stock motor and the intake ports are properly sized for a 318 cylinder head.


Ron

[Ponch ®]

However, with one side of the intake bolted in, theres about a 1/8 of an inch gap on the other side between the intake and the head (w/ gaskets).

There are 2 possibilities here;

(1) The manifold has been milled to fit another motor which had some decking/milling

(2) The manifold was defective from the get go.


If your block and/or heads were shaved the manifold would be too tall (not too short) and it would sit on the heads but the boltholes would not line up. This is not the case and from what you're describing....the manifold is the problem. My guess is that this was a used manifold that was modified to fit someone else's motor...


Look on e-bay for an old edelbrock LD4B intake....those work very well on a stock motor and the intake ports are properly sized for a 318 cylinder head.


Ron

I bought the manifold brand new when i was trying to change it on the old engine. I always figured that the old engine had been milled because I tried using at  least 3 different manifolds with it and none worked. It might be defective - unless someone bought it, milled it, and returned it and then i was the unlucky sucker that bought it again. BTW - the engine im trying to put it on is a 360 i bought a few months ago.

Before I spend more money on a new manifold, im gonna try to see if someone i know has a 'stock' manifold i can try on it. if it fits, then my manifold is bad.

[Ponch ®]

heres what the engine looked like when i was mocking it up and test fitting stuff on it.




before:

[firefighter3931]

Ponch,

Have you tried sitting the manifold on top of the engine w/o the end gaskets in place ? I'm curious as to how close it is to lineing up ?

Maybe give that a try....and see if you can start the bolts on both sides of the intake. It's possible the rubber end gaskets are raising the intake up and causing the alignment issues. 

This is assuming that the end gaskets are installed, of course....

Ron