Unstoppable Coolant Leak

[AJ/FormS]

Does this mean mill the bottom plane? Sorry, got busy and haven't thought too much on it just trying to figure it out. That'd be around .015 each side clearance, gasket is .060" thick so around .040-.045" on each side, it'd lift the intake up a bit. I have a new set of gaskets and I'll set this on tomorrow as well and measure China wall clearance.

no; there ya go; what 512Stroker said.
That should work out OK, if the planes are all parallel.
But I sure wouldn't bolt it all back together until I found the source of that running water.

 

[Charlesvolare]

i had a edelbrock 340 victor on my small block without any issues then bought a speedpro chinese air gap manifold and put it on but it ran like crap, possibly an air leak in the valley somewhere so I bought an edelbrock air gap and replaced it and have not had any issues ever since. I think the chinese manifold did not have the correct angles on the intake surfaces as I have never had a manifold leak air or coolant before. the quality control of those manifolds appear to be suspect. Change the manifold now!

I've used this manifold for 3+ years and this is the first major problem I've ever had with it. It's not American made, but seems to be pretty decent quality from what I can tell. I'll check the angles in the morning and see if that's indeed the problem or not.

 

[Charlesvolare]

And again I've had this problem before (but not as bad) and thats why I ended up milling the heads. It could very possibly be that my deck is warped, bit I'd think flatter heads would at least help with that and not make the problem more prominent.

Another thing is the material between the coolant port and mounting holes is pretty narrow. I ran and took some measurements real quick. If it were pushing out, this would be the narrowest spot. But it could have nothing to do as well,just thought I'd put everything out there just in case.

 

[MopaR&D]

That is a really thin sealing area, definitely thicker on all the Edelbrocks I've messed with. It almost looks like the water port is too big and not getting completely covered by the gasket just by the way the mating surface looks around that water port on the manifold...?

 

[512Stroker]

And again I've had this problem before (but not as bad) and thats why I ended up milling the heads. It could very possibly be that my deck is warped, bit I'd think flatter heads would at least help with that and not make the problem more prominent.

Another thing is the material between the coolant port and mounting holes is pretty narrow. I ran and took some measurements real quick. If it were pushing out, this would be the narrowest spot. But it could have nothing to do as well,just thought I'd put everything out there just in case.View attachment 1715372768 View attachment 1715372769 View attachment 1715372770 View attachment 1715372772

One option would be to have the intake checked for cracks.
If it is not an intake problem, it is a head problem.
Look for the easy answers first.

 

[B3RE]

Don't overlook the possibility that the coolant is coming out around the water ports in the timing cover. I've had gaskets deteriorate in that area, and it makes everything wet, which can look like the manifold leaking when it isn't. I'm leaning toward the manifold myself, but just cover all your bases and check the timing cover as well, especially if it was running for a while with no leaks. Even the FelPro gaskets will disintegrate, and the timing covers corrode in that area too.

 

[RustyRatRod]

In regards to the service manual intake torque spec, keep in mind a lot of service manuals incorrectly listed the rocker shaft bolt torque for the LA engines at 30 LB FT. Lots of people have broken those 5/16 bolts off, too. That's in there wrong. It should be 15-17 LB FT. So it's possible that 12 LB FT is incorrect. It certainly sounds like it's not tight enough to me. Just one man's opinion.

 

[famous bob]

In regards to the service manual intake torque spec, keep in mind a lot of service manuals incorrectly listed the rocker shaft bolt torque for the LA engines at 30 LB FT. Lots of people have broken those 5/16 bolts off, too. That's in there wrong. It should be 15-17 LB FT. So it's possible that 12 LB FT is incorrect. It certainly sounds like it's not tight enough to me. Just one man's opinion.

We assume u have compared the gaskets , bolt holes lined up , w/ the water and intake ports on the heads and intake ??

 

[Charlesvolare]

Update: Spent a Saturday checking angles and every possible alignment aspect. It wasn't perfect but was within a reasonable tolerance. I put it back together making sure the gaskets were perfectly aligned, especially the tight spot between the coolant port and bolt hole. I let the rtv cure for two days before adding fluids and starting the engine. I have a week of solid driving and no more leaks as of now.

 

[tonysrt]

I just heard the big sigh of relief after you checked for that leak again and noticed it was gone.

 

[3406pk]

Good for you. All the patience and checking paid off.