2806178 Intake Manifold Replacement - What Date Code do I need?

[kiwigtx]

No time for me to back read. Have the heads ever been planed? (machined) If so, depending on how much they milled off, the intake surfaces will not match the intake surface angles.

That manifold may have been machined in the distant past to match a set of heads that were shaved - which means that any new heads will never match the manifold.

I know this from experience.

Also....be aware @Michael_ that there are different 440 intake gaskets (Turkey pans) - some with heat exchange holes, and some without.

(Disclaimer ....I didn't back-read that much either.)

 

[Michael_]

So meanwhile the new NOS gaskets arrived and yesterday we redid the job.
Same story. It held up for about 30-40miles and then started leaking again. Pretty bad and on both sides. I can almost kill the engine spraying carburetor cleaner along the left or right side of the intake manifold.
This time we did not use any RTV except on the china walls. We reused the original manifold this time around.
We dry fitted the intake manifold (without the valley pan) and used a straight edge on both the heads and manifold and it looked good to us. But we are not engine builders so take this statement with caution.
We used 40 ft lbs of torque and used the right torque sequence.
We reused the original intake manifold bolts but they looked fine and this is not a problem from what i researched?

Anyway at this point i think it can only be both heads being warped or both intake manifolds being warped. (Or the second one i bought being machined in the past and/or both heads being machined in the past)

I do not really see another possibility. Do you guys?
(In some of my earlier posts i also posted a bunch of pictures of us changing the gasket if you want to look at those.)

At this point i get the feeling that the first owner parked the car after getting the diagnosis of 2 warped heads.
And the guy who sold the car to me probably also found that out and then sold the car to me...
And i probably didn't even notice at first until it got worse...

 

[Orig69]

I don't know that. It would surprise me but at this point also not that much.
But what do you do in this case i mean taking something off the manifold just makes this worse i assume?

The case against this is that i own the car for 5 years now and while i have not been driving nearly as much as i wanted because of unplanned personal stuff happening i have surely put at least 500 miles on the car before it started leaking.
Also the old valley pan gasket looked like it has been in there for a long time. Though while i don't know for sure i think it was not the first/original one.

Do you have a picture of the original valley pan?

 

[Michael_]

Do you have a picture of the original valley pan?

Unfortunately i threw it away but YES i do have a picture: My Gallery — Postimages

 

[Orig69]

Unfortunately i threw it away but YES i do have a picture: My Gallery — Postimages

That valley pan was the same Fel-Pro ms 96000 that you already have.

It would only be unfortunate if it was physically thicker than the new ones.

 

[66 Sat]

We dry fitted the intake manifold (without the valley pan) and used a straight edge on both the heads and manifold and it looked good to us. But we are not engine builders so take this statement with caution.

How did you use the straight edge? In conjunction with some feeler gauges? Or just by sight?

 

[kiwigtx]

So meanwhile the new NOS gaskets arrived and yesterday we redid the job.
Same story. It held up for about 30-40miles and then started leaking again. Pretty bad and on both sides. I can almost kill the engine spraying carburetor cleaner along the left or right side of the intake manifold.
This time we did not use any RTV except on the china walls. We reused the original manifold this time around.
We dry fitted the intake manifold (without the valley pan) and used a straight edge on both the heads and manifold and it looked good to us. But we are not engine builders so take this statement with caution.
We used 40 ft lbs of torque and used the right torque sequence.
We reused the original intake manifold bolts but they looked fine and this is not a problem from what i researched?

Anyway at this point i think it can only be both heads being warped or both intake manifolds being warped. (Or the second one i bought being machined in the past and/or both heads being machined in the past)

I do not really see another possibility. Do you guys?
(In some of my earlier posts i also posted a bunch of pictures of us changing the gasket if you want to look at those.)

At this point i get the feeling that the first owner parked the car after getting the diagnosis of 2 warped heads.
And the guy who sold the car to me probably also found that out and then sold the car to me...
And i probably didn't even notice at first until it got worse...

How easy was it to get the intake bolts started? If it was difficult - that might indicate a heavily machined surface on either the block or the heads.

If it turns out the block has been shaved and the heads milled..... maybe using a new 'turkey pan' (valley tin gasket) plus additional 'paper' gaskets to take up the slack might help - it might need a paper gasket each side of the tin gasket if the milling is really bad.

Just a thought....and just my opinion. I had a shaved block and milled heads a long time back and it was a real PITA to get right.

 

[Michael_]

That valley pan was the same Fel-Pro ms 96000 that you already have.

Yes i know. That's why i came up with the theory that the first owner of the car had the valley pan replaced but this did not fix the leak.
Then his mechanic told him this is something bigger and he decided to park the car.
A Couple decades later someone else sold the car to me either knowing or not knowing about this issue.
I didn't even notice at first until it got worse...

Just a theory though and i have already been wrong 2 times in the past suspecting the new fel-pro gasket and the RTV.

How did you use the straight edge? In conjunction with some feeler gauges? Or just by sight?

Just by sight.
Truth is we didn't go too deep because we already knew we cannot fix this ourself if the angles are off or some surface warped.
We were all hoping it was the RTV but unfortunately that was not the case.

How easy was it to get the intake bolts started? If it was difficult - that might indicate a heavily machined surface on either the block or the heads.

If it turns out the block has been shaved and the heads milled..... maybe using a new 'turkey pan' (valley tin gasket) plus additional 'paper' gaskets to take up the slack might help - it might need a paper gasket each side of the tin gasket if the milling is really bad.

Just a thought....and just my opinion. I had a shaved block and milled heads a long time back and it was a real PITA to get right.

It was pretty easy to get those bolts started.

Also again this was the old valley pan that we pulled out: My Gallery — Postimages
It was in there without any paper gaskets or RTV which makes it hard to believe someone actually milled the heads or block.
But of course maybe this one (installed under previous owner ship) also never sealed (Initially better but never fully)...

Anyway the next step will be taking the car to a professional because this is a bit too advanced for us to tackle.