Alum head water passage

fast64ranchero

Well-known member
I ran into a issue with my head, pretty easy fix but for those of you that have the head check the water jacket at the rear of the head for proper alignment with the head gasket. The Fel Pro gasket matched the block very well but not so much the head.
 

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Looks like the head gasket was trimmed very narrow on that last cooling passage you wouldn't want do that. It would be better to leave the head gasket as it was made even if it overlapped the heads cooling passage that wouldn't hurt the flow enough to bother with however you could open up the passage to the outside if you were worried about it.
 
Looks like the head gasket was trimmed very narrow on that last cooling passage you wouldn't want do that. It would be better to leave the head gasket as it was made even if it overlapped the heads cooling passage that wouldn't hurt the flow enough to bother with however you could open up the passage to the outside if you were worried about it.
The head gasket is not trimmed or modified in any manner, it is as Fel Pro made it and it fits the block passages perfectly.
Maybe my head had core shift of they all are like this. The coolant witness marks show how far off that passage is on my Alum head
 
Well that's interesting in the picture it looks like the gasket is much narrower on the one rear passage. Yes definitely looks like there is some core shift of those cooling passages. Are you planning to weld up those places were there is shift to fix it?
 
if it passes the pressure test it will go out for the repair of the water passage. don't want to put it back on without fixing it. Really hoping it doesn't have an issue with the push rod holes as I had them opened up on one side for push rod clearance. Pressure test will tell the story.
 
It is always something, it is never easy. I could be wrong, but I think that it is something else. That should have sealed considering that no pressure was put on it.
 
I'm thinking it has to be somewhere from the block to head sealing surface area and up. The reason I think that is it only leaked when the radiator top tank was full, as soon as the top tank got to about half full the in the top tank, the leaking would stop. To me this indicates something high on the engine. When I pulled the valve cover there was no sign of antifreeze.

I'm totally open to suggestions on where to look. the front 4 cylinders (1-4) were dry when I pulled the head, 5 an 6 were wet which was prob from removing the head. I had the shop check the head surface for flatness, it had 1.5 thou warp not enough to cause a problem.
 
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I am curiours to see what you find. I don't know if maybe the head you got was from a strange batch. Don't know how many were produced at a time.
 
I'm thinking it has to be in the head of block to head sealing surface area. The reason I think that is it only leaked when the radiator top tank was full, as soon as the top tank got to about half full the in the top tank, the leaking would stop. To me this indicates something high on the engine. When I pulled the valve cover there was no sign of antifreeze.

I'm totally open to suggestions on where to look. the front 4 cylinders (1-4) were dry when I pulled the head, 5 an 6 were wet which was prob from removing the head. I had the shop check the head surface for flatness, it had 1.5 thou warp not enough to cause a problem.
Do you have a ci alumn head or is it a vintage inline head ? I'll have to check my head to see how the gasket matches that area. My head is a ci head s# 009 so I'm hopeing it's all good.
Thanks for that heads up .
 
My head is a VI Head. Still waiting for the head to get pressure tested, every auto machine shop around me is backed up 6 months.
 
It is always something, it is never easy. I could be wrong, but I think that it is something else. That should have sealed considering that no pressure was put on it.
Well, I have a hole in a push rod passage where I opened the passage up for the larger 3/8" push rods. Guess I'll sleeve it, wonder if a press fit would work or will I have to weld the sleeve in place?
 
That is a tough one, hate to mess up a rare head. If the sleeve is an easy to weld alloy, I think that a small quick bead would work with little distortion. Or maybe make the sleeve with just enough space for epoxy and use the best epoxy you can find. Then again maybe press or warm head and super cool sleeve may work, not sure.
Shame that they missed the pushrod layout. Stock head and rockers the 3/8'' pushrods fit with no mods,
I think that going forward that quality 5/16'' pushrods should be used on AL heads and minimum material be removed. They say that a little rubbing is not a problem, but not sure I would try that.
 
I should have just ran mine like you did. Oh well live and learn. I ended up having a sleeve made. The sleeve is 0.752 to press fit and the inside will be opened up after installing the sleeve and welding the sleeve in.
 

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Head Pushrod hole was bored on a CNC and reamed to 0.750", I modified the sleeve to press fit 0.752" and 2.25 long. The head is at the welders now. Both sides will be welded along with fixing the water passage to fit the head gasket. Getting close, but, still crossing my fingers as things can still happen..
 
Sleeve Welded in, but they didn’t weld the water passage. So back at the Weld Shop
 

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