barnett468

i can't see it really well on my screen. are you talking about the section that bulged part way into the intake?

if so, it can be caused by using silicone. silicone makes the gasket slipperier than a greased pig which allows the gasket to slide all over until the bolts are tight enough to prevent it from sliding.

old school paper gaskets are actually good and won't bulge like that if you use silicone.
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Gun Jam

Yes mostly

I used alignment pegs when I set the intake on to keep anything from moving.

It might be hard to see but the gasket actually stayed in place but became misaligned because it was extruded between the intake and the head. This caused it to distort and crack eventually leading to a water leak. Both times I tried using them and both times I got the same issue.

The bolts actually stayed put none of them were loose.

I took significant care installing them and had poor results. Maybe there is a slight misalignment between the head and the intake but isnt that the point of the gasket?

Switched to ederbrock 7220. Sealed perfect no distortion or cracking just the damn blockoff plates for the x over didnt fit well. The gaskets looked brand new when I pulled them off...These are the intake gaskets I would recommend and if 1250s were used in the OPs application I might suspect them as a culprit especially since its plug 4 and 8 the ones at the end of the run where I encountered the most extreme distortion and failure of the 1250.

-Gun

barnett468

Hi;

unfortunately, the pegs do nothing to keeo the gasket from squishing out like yours did.

it is also just a coincidence that yours was bad on the same two cylinders that he is lean on. there is nothing in the design of the gaskets or the STOCK head and intake that would cause this problem on one end but not the other.

some of the aftermarket intakes are not machined correctly/square which can cause some probs.

one good way to keep them from bulging out is to use gasket cinch on the cylinder head side. once they are glued in place, use silicone on the other side only. the silicone allows the intake to slide over the gasket while it is being tightened down. this prevents it from tearing and the gasket cinch prevents it from bulging.

unfortunately, none of the gasket mfgs tell people this, lol.

you can also install them dry if you dare.
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67mustang302

That exact same failure happens a lot on the 1250's though. I'm wondering if they changed the material they use in more recent years. Or it could be a combination of things, regions with wider temperature extremes from season to season mixed with certain head/intake combos.

barnett468

not when i install them but i haven't used them for a few years, however, i doubt they changed their material but could be.

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