Intake leaking, heads milled?

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dkbug

dkbug

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I can not get my intake to stop leaking. 3 intake gaskets later and I still have a small leak on one entire side. (drivers side) In order to get the intake bolted in, I have to bolt in one side and use a pry bar to push down the other side to get the bolt holes lined up. Based on what I have done over the years as an engineering student, there is NO way that is correct.


I had my heads worked over by a machine shop. They did a valve job and said that they "resurfaced" the heads. Does this mean they milled the heads? If they did in fact mill them, would I not need to mill my intake as well? Is there a way to check how much was milled off the heads without dissembling them? Depending on how much was milled from the heads, how much should be taken from the intake?

What would you guys do?

Thanks in advance FABO,
Dakota
 
I am using a Weiand aluminum dual plane intake that is unmolested to my knowledge.
 
You shouldn't have to pry on the manifold at all to get it to line up.

Ask the machine shop what their "resurface" means.

On a big block Chrysler .0123" should be removed from the intake side of the head for every .010" from the combustion chamber side. Stock, the head should be about 1.000" thick where the short head bolts go through the head on the exhaust side.

I would lay the intake on the engine with no gaskets in place and check bolt hole alignment. Using feeler gauges, see what clearance you have on all four corners, top and bottom of the intake. If the intake manifold bolt holes are high, the head intake side or the intake manifold must be milled. We sometimes have to do some angle milling of the intake to get it to line up parallel with the heads.
 
IQ52 said:
You shouldn't have to pry on the manifold at all to get it to line up.

Ask the machine shop what their "resurface" means.

On a big block Chrysler .0123" should be removed from the intake side of the head for every .010" from the combustion chamber side. Stock, the head should be about 1.000" thick where the short head bolts go through the head on the exhaust side.

I would lay the intake on the engine with no gaskets in place and check bolt hole alignment. Using feeler gauges, see what clearance you have on all four corners, top and bottom of the intake. If the intake manifold bolt holes are high, the head intake side or the intake manifold must be milled. We sometimes have to do some angle milling of the intake to get it to line up parallel with the heads.
Click to expand...

When I called the machine shop yesterday, the only answer I could get was if they did mill any, it wouldn't have been any more the .006".... That's a big number to me.... He does not have any records from when I had my heads in there seeing as how it was over a year ago.


Now this is what is interesting. I did this method and all the holes seemed to line up the way they should, and the intake SEEMED to be flush with the heads... With gaskets and windage tray in place, they do not. It seems as though the thickness of the gaskets put the intake side higher than the bolt holes on the cylinder head
 
If it mates up as you say. New valley pan, no paper gaskets, no RTV, we do it all the time. With the proper intake alignment, as described, we reuse only the tin for four or five intakes during dyno tests. Tighten both sides evenly, not one side first.

All factory engines used the valley pan only. No gaskets, no sealer.
 
In the middle of the night I remembered the obvious, put dabs of silicone in the four corners where the heads meet the block on the rails front and back of the engine.
 
Turns out my intake is not square. I put a straight edge on it and shined a light on the other side. It kind of looks like a wave. How much can I machine an intake without getting dangerous? How can I find out how much I need to mill it?
 
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