Intake manifold won't seal - How do I check it ?

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Earlier I noticed you said your machinist said you needed .100 thick gaskets and you didn't know where to find them. If you do end up needing thicker than normal gaskets Cometic will make a set for you for nearly the same price as a normal gasket. Last time I talked to them they told me they made them in .017" increments so you could get some made that are .102" thick. Last time I bought some from them ( 2 yrs. ago) they cost about $30 shipped
 
You don't have some sort of ridiculous port SIZE mismatch, with heads, intake, gaskets?

Set that damn thing on the engine, and SIGHT into it from the front. You'll see immediately if the angle thing is a problem
 
67Dart273 said:
You don't have some sort of ridiculous port SIZE mismatch, with heads, intake, gaskets?

Set that damn thing on the engine, and SIGHT into it from the front. You'll see immediately if the angle thing is a problem
Click to expand...

Going to do that tomorrow.
 
fishy68 said:
Earlier I noticed you said your machinist said you needed .100 thick gaskets and you didn't know where to find them. If you do end up needing thicker than normal gaskets Cometic will make a set for you for nearly the same price as a normal gasket. Last time I talked to them they told me they made them in .017" increments so you could get some made that are .102" thick. Last time I bought some from them ( 2 yrs. ago) they cost about $30 shipped
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Thanks for that info fishy68. I was a little worried where I would find the thicker gaskets.
 
I can't see a gap with the intake sitting on the engine with new gaskets in place. It is not bolted down just a couple bolts on each side to keep gasket in place. I pushed the intake to one side of the engine and slid a feeler gauge down between the intake and gasket and I could only fit a .007" gauge in there.
 
That .007" gap is consistent in several locations?? Maybe "switch" sides and see if you have the same gap in several spots on opposite side??
 
4spdragtop said:
That .007" gap is consistent in several locations?? Maybe "switch" sides and see if you have the same gap in several spots on opposite side??
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I checked the whole passenger side but I now I feel that I should have pushed it to the other side and checked it too.
 
duster360 said:
I checked the whole passenger side but I now I feel that I should have pushed it to the other side and checked it too.
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Yeah, trying to do the "geometry" in my head and wondering if one side or angle is off, will it show on both sides or just one?? Chiming in when I can with my limited knowledge.
 
OK, with my limited experience in motors, I have a 318 with 360 "J" heads.
This is how I got the car/engine.

My problem was losing a quart of oil in 45 miles! NO VISIBLE smoke, no leaks, nothing visible.

These heads had to be milled down on the face (Piston Side) to get the compression back up.
This throws off the alignment of the intake side.
The intake was taken off and the gaskets were screwed up, sucking oil directly into exhaust but not burning it.

I'm in process of getting measurements to have intake milled. I have put the thickest gaskets with "right stuff" gasket sealer on top of that. The oil consumption has almost stopped, but still has a slight oil leak on front and back of intake that bothers me.

Thanks to everyones great experience and knowledge here, I'm close to having this solved.
 
JefftheComputerMan said:
OK, with my limited experience in motors, I have a 318 with 360 "J" heads.
This is how I got the car/engine.

My problem was losing a quart of oil in 45 miles! NO VISIBLE smoke, no leaks, nothing visible.

These heads had to be milled down on the face (Piston Side) to get the compression back up.
This throws off the alignment of the intake side.
The intake was taken off and the gaskets were screwed up, sucking oil directly into exhaust but not burning it.

I'm in process of getting measurements to have intake milled. I have put the thickest gaskets with "right stuff" gasket sealer on top of that. The oil consumption has almost stopped, but still has a slight oil leak on front and back of intake that bothers me.

Thanks to everyones great experience and knowledge here, I'm close to having this solved.
Click to expand...

How thick are the gaskets your using?
 
Update.
I put some plasti gauge on the intake next to the ports. Put the gaskets on the heads, set the intake on and tightened it down. Pulled the intake back off and gauged the strips. They were a consistent .004" from top to bottom.
 
They should be smashed to nothing, they are .004 thick? Are your intake bolts too long? Did you plastigage without the gasket?
 
I did plastigage with the gaskets. The gaskets are Edelbrocks with the sealing bead around the ports. I put the plastigage just outside the bead. A section of the plastigage did run through the bead on one port and it smashed to nothing. The plastigage is .004" thick according to the chart that the plastigage comes in. Bolts are not too long and thread all the way up.
 
At the moment I have .060" thick intake gaskets. I found some that are .094" thick. Are there any downsides to using such a thick gasket. Will it start moving the intake upwards on the ports?
 
I would try to install it and see what happens, glue the gasket to the head and bolt it down starting from the center out in a cross cross pattern. Run it then retighten
 
inertia said:
I've run across a few intakes that were bent when they were sucked down over the locator pins, when there was no reciprocal holes in the manifold, front and back..

They sucked oil as you described,, from the bottom of the gskts... also had pin impressions in the manifold..
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Ha, I did that once, cracked a 273 4bbl intake mounting it on a pinned 318. Dough! :-(
Modeling clay works too

You said the intake ports were smaller than the gaskets, like they were overhanging the bottom of the port? You sure you got 360 heads? Sounds like teen heads with 360 gaskets. That won't seal. Just put a bead if modeling clay around the ports and drop the intake on it and snug the bolts. Remove intake and measure how thick the clay us top and bottom, t should be equal ten buy a slightly thicker gasket.
 
Definitely 360 heads. Came factory on my 340 with big valves. The ports on the intake are smaller. The heads ports are large and gasket matched.
 
EL5DEMON340 said:
I noticed on my mopar 6 pack there is not a lot of "meat" at the bottom of the ports, this is a better one! a couple are a bit thinner.
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My intake looks just like the one EL5demon posted a picture of on this thread. Looks like they were cast with 318 ports. I will be opening mine up like EL5demon is doing.
 
duster360 said:
At the moment I have .060" thick intake gaskets. I found some that are .094" thick. Are there any downsides to using such a thick gasket. Will it start moving the intake upwards on the ports?
Click to expand...

Thicker gaskets will definitely move the intake up. I had to use .093" thick gaskets on mine because someone cut the intake. The .093" gaskets helped align mine but could be a detriment to yours. All depends on what yours needs for proper alignment. You can usually get a good idea just from the bolts. If their not centered good it's a sign something may be off. How centered are your bolts with the intake just setting on the .060" gaskets before you screw it down? If it looks like the bolts are setting high in the holes with the intake just setting on the gaskets before you tighten it down thicker gaskets may help. If their centered good or even low thicker gaskets may be bad. Since you said the plasti gauge squished to nothing it sounds like things aren't too far off. I haven't used the Eddy gaskets but have had a set of Fel-Pro's suck oil in even when things were aligned real good and was plenty tight.
 
duster360 said:
Any more advice for checking before I try this again.
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Just spitballin' here, do you still have the little tabs on the head gaskets intact, the tabs that hold the intake gasket up for alignment? IF so where are they positioned, are they set to be under the bottom of the intake, or did you fold them up so they are pinching between the intake/head surface???
 
fishy68 said:
Thicker gaskets will definitely move the intake up. I had to use .093" thick gaskets on mine because someone cut the intake. The .093" gaskets helped align mine but could be a detriment to yours. All depends on what yours needs for proper alignment. You can usually get a good idea just from the bolts. If their not centered good it's a sign something may be off. How centered are your bolts with the intake just setting on the .060" gaskets before you screw it down? If it looks like the bolts are setting high in the holes with the intake just setting on the gaskets before you tighten it down thicker gaskets may help. If their centered good or even low thicker gaskets may be bad. Since you said the plasti gauge squished to nothing it sounds like things aren't too far off. I haven't used the Eddy gaskets but have had a set of Fel-Pro's suck oil in even when things were aligned real good and was plenty tight.
Click to expand...

The bolts do sit very high in the bolt holes. I noticed that the bolts at the rear of the intake actually rub the top of the hole and are difficult to start.
 
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