LA engine intake gaskets: Are there any options for thinner cork gaskets for the front and rear segments?

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Kern Dog

Build your car to handle.
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There have only been a few times that I have seen this but today I was helping a friend install an intake on his 5.9/408 and with the standard cork gaskets that sit on the front and rear walls, the holes in the heads for mounting the intake were not in alignment. The intake is aluminum and it looked to me like putting a bolt in there could damage the threads. With the cork gaskets out and a thick bead of RTV, the mounting holes lined up okay.
It seems like there should be a thinner gasket for situations like these. The Fel Pro cork gaskets are a strong 3/16", maybe a hair more. Are there any options here?
 

I always toss the cork, silicone works great, as long as it cures properly... After years in the auto repair trade I saw far to many cork gaskets that pushed out & cause a massive leak...
 
I always toss the cork, silicone works great, as long as it cures properly... After years in the auto repair trade I saw far to many cork gaskets that pushed out & cause a massive leak...
Yepper, and it's the back one so pours out when car/truck moves forward.
And guys diagnose it wrong thinking it is the distributor or sender leaking
 
There have only been a few times that I have seen this but today I was helping a friend install an intake on his 5.9/408 and with the standard cork gaskets that sit on the front and rear walls, the holes in the heads for mounting the intake were not in alignment. The intake is aluminum and it looked to me like putting a bolt in there could damage the threads. With the cork gaskets out and a thick bead of RTV, the mounting holes lined up okay.
It seems like there should be a thinner gasket for situations like these. The Fel Pro cork gaskets are a strong 3/16", maybe a hair more. Are there any options here?
I had the same exact same problem last year on an LA 318 with 302 castings and an Edelbrock performer.
I looked online for a week and couldn't find any. I finally gave up looking and siliconed it.
 
Silicone is the gold standard- not a hack. One should not be put off by using silicone only for the China walls. Even the other brands do it. Good seal.
I agree the Gray Stuff is DA Bomb! Just look at all episodes of Engine Masters. There was some serious Tallent on the show and all they did was silicone, and little around the water ports just to be 100%.
 
Remember to prep/clean the intake area and the block so the sealer (gray) will stick, about 12 years ago my Chebby friend called and said he can't get his new aluminum intake on, so I told him to trash the cork and use gray permatex high heat, then he said he had 4 dodge wheels here I could have for my time so off the lawn mower that morning and jumped in Victoria for a 30 mile drive, he said the intake was already prepared so I picked it up and there was an oily substance on the bottom.... hmm, I was the proud owner of 4 mopar road wheels lbp 14inc..
 
Check the locator pins in the China Walls. Many/most aluminum intakes don't have holes to accept the pins. Either mark and drill the intake or pull the pins out with Vice Grips. The cork gaskets are usually too thick and don't compress well. You can trim them thinner but they must be left thick enough to compress a bit or they will leak. Like mentioned many times above. A bead of silicone works well. I squeeze out a bead, install the intake and let it set overnight before starting the engine. Silicone is an aerobic sealer and needs air to cure.
 
If you do go silicone, set the intake on first so you get a good idea of how high to go... i ran a thick bead, sat the intake down and it barely touched.. ran a second bead on top after taking it back off and cleaning up some mess..
 
If you do go silicone, set the intake on first so you get a good idea of how high to go... i ran a thick bead, sat the intake down and it barely touched.. ran a second bead on top after taking it back off and cleaning up some mess..
Exactly. Always dry fit.
 
More than a decade ago, my parts guy suggested a set of new style Felpro intake gaskets.

The heat cross-over blocked, and the China wall cork gasket was about half as thick as the standard intake gaskets sets, specifically for aluminum manifolds, a coupla dollars more.

I used to do the RTV thing on the China wall, but these new gaskets allow the manifold to sit as it should, bolts align a lot better.
I use 3M weatherstrip adhesive to secure the cork gasket in place, it stays put.
These gskt apparent were produced to solve the RTV thing,

I don't remember the number, my parts guy just supplies the proper gskt without being asked.

I suspect they are Felpro 1213 - S-3.

BUT DO COMPARE AND CHECK !


Haven't used RTV on the Chinawall in years, but when I do use RTV. - I use the "Right Stuff"

Good Luck
 
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used this on my 360..

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For a piece of mind I use the gray stuff on my derby motors also and they sometimes have zero coolant are God only knows how hot they get running wide open throttle for 25+minutes with no cooling system and motor only gets refreshed once something breaks so if it holds up to that abuse you have a piece of mind for the street.
 
WOT for 25 minutes with no water running through it?
I'd need to see that to believe it.
 
Gasket user here , as said above dry fit with no end gaskets (may have to use different thickness side gaskets) then measure end gaskets and use stock or cut your own from cork gasket material. I glue the end gaskets down with weatherstrip adhesive , then run a LIGHT bead of right stuff on top , around the water ports and a nice glob at each corner , slap on the intake and torque to specs . Dry fitting is most important checking for port and bolt alignment .
 
A lotta early factory china wall gaskets were actually spongy foam rubber, easily compressed, but changed to cork because they deteriorated and weeped oil .
 
WOT for 25 minutes with no water running through it?
I'd need to see that to believe it.
Watch almost any derby video. Headers glowing red melted trans filters with just the ring left. Melted boots from the transmission bell housing. We purpose build engines to run specifically with no coolant once the rad gets toasted.. it's not non stop wide open but nonetheless it's still zero coolant flow one the fan is through the radiator
 
WOT for 25 minutes with no water running through it?
I'd need to see that to believe it.

Lol..
Respectfully Kern Dog, Owen is right, sorta.
We ran a lotta demo Derbys, We won the Can/US demo derby a few times at our Pacific Nation Exhibition.
They'll run a long time, many times, then total destruction at the end.
24 volt to start em, 12 volt to run
Last car moving wins.
We liked Kingswood wagons.
Cheers .
 
I’ve watched plenty of demolition derbies but never knew about how the engines were cooled.
 
I’ve watched plenty of demolition derbies but never knew about how the engines were cooled.

After the rads gone/toast, - ( first coupla heats ) - fan off, - use a piece of exhaust pipe to connect top to bottom rad hose, - fill as best possible, - then it's a time/endurance bomb, - after the poof of steam when the hoses blow ,- they still run a long time .
Knowing the weak point of the opposition, SunTsu, - Lincolns was steering column connection.

 
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