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what gaskets to use on HEMI with bathtub intake ?

Posted By: docford

what gaskets to use on HEMI with bathtub intake ? - 12/26/10 10:53 PM

The intake gaskets (I currently use Fel-Pro) of my roundy-round 426 HEMI do developp leaks in the lifter valley. The issue is mainly due to the fact that the heads intake runners are very heavily ported and that the manifold has not much of a seating surface either. So once the intake gaskets settle under heat, they start to leak and oil gets sucked in the intake runners!!

Here are some pictures:
http://www.olympia-charger.com/2006/06/our_motorvation.html

Are there intake gaskets of different thickness for the race HEMI?

What gaskets would you use on an Edelbrock Rat Roaster intake, which is similar to the NASCAR bathtub?

Attached picture 6379257-HEMIbathtubGroup2Cuda.jpg
Posted By: WILD BILL

Re: what gaskets to use on HEMI with bathtub intake ? - 12/26/10 11:27 PM

PM Roadhazard.

I'm sure Greg will be able to get you sealed up.

Posted By: docford

Re: what gaskets to use on HEMI with bathtub intake ? - 12/27/10 09:25 AM

will do, thanks

Any other idea? Can these gaskets be custom ordered?
Posted By: docford

Re: what gaskets to use on HEMI with bathtub intake ? - 12/29/10 11:30 AM

I found three gasket models for the 426 HEMI

Mr.Gasket 1/16" thick #303G
Mr.Gasket 1/8" thick #311
Fel Pro 0.060" thick #134-3075

The Mr.Gasket look interesting, as they are probably less prone to wrap by design.

Even though I personally prefer Fel-Pro for their quality, I'm tempted to give the Mr.Gasket models a try. Who has ever used Mr.Gasket 426 HEMI intake gaskets in a racing application and what is your experience?

Can you recommend a company that can make these in 3/32" thickness?
Posted By: quickd100

Re: what gaskets to use on HEMI with bathtub intake ? - 12/29/10 12:04 PM

All I use are the Mr. Gasket units. One thing about a hemi, when you change intake gaskets torque, retorque, retorque, retorque, retorque, and retorque again. It takes a few times before the gasket settles in, otherwise you end up with leaks as you describe. Dave
Posted By: CRE2004

Re: what gaskets to use on HEMI with bathtub intake ? - 12/29/10 02:45 PM

Exactly what Dave said about the torque. I have spoken with roadhazard a couple of times about the hemi gaskets and without volume, it didn't look promising. Maybe that's changed. I've used the fel-pro and Mr. Gasket gaskets. Both work ok. For a real good seal, I custom cut the FelPro 1290 prostock material.
Posted By: Cab_Burge

Re: what gaskets to use on HEMI with bathtub intake ? - 12/29/10 07:07 PM

Seal the gaskets first with a good brand gasket sealer, install them and leave the top off, retorque them several times over a period of several days until none of the fasteners move when attempting to retorque. Run the motor , let it warm up several times and remove the lid and retorque again once or twice before reinstalling the lid reason # 864 for calling them motors Hemiroids
Posted By: docford

Re: what gaskets to use on HEMI with bathtub intake ? - 12/29/10 07:18 PM

thanks for your advice! What sealent would you use on the bolts threads and heads? Since on the bathtub the manifold bolt heads are inside the plenum, the sealant need to be gasoline proof!
Posted By: Cab_Burge

Re: what gaskets to use on HEMI with bathtub intake ? - 12/29/10 08:38 PM

Quote:

thanks for your advice! What sealent would you use on the bolts threads and heads? Since on the bathtub the manifold bolt heads are inside the plenum, the sealant need to be gasoline proof!


I like and use Gasketcinch, the one with the Ice Skating girl falling down on the can( I think that is the symbol ) Summit sells them in several sizes, I buy four of the little cans at a time so I don't run out in the middle of a project, order four more when I open the last can Permatex Hightac gasket sealer works also
Posted By: Hemi Allstate

Re: what gaskets to use on HEMI with bathtub intake ? - 12/29/10 09:38 PM

Quote:

thanks for your advice! What sealent would you use on the bolts threads and heads? Since on the bathtub the manifold bolt heads are inside the plenum, the sealant need to be gasoline proof!




I like the Mr Gasket 303G gaskets, glued with Gasgacinch . As stated above many re-torque procedures will be necessary. On the threads I like Peramtex #56521.
Mark
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