L98 Manifold Question...
Thread Starter
Safety Car
Joined: Feb 2000
Posts: 4,564
Likes: 110
From: Austin Texas
L98 Manifold Question...
Anyone ever try using Permatex Form-a-gasket to do the runners?
The reason is my front drivers side pair has started to suck external air...I've snugged the bolts and it is still doing it. New gaskets are gonna be a PITA as my large-bore runners and siamesed manifold don't exactly conform to any of the "standard" manifold gaskets.
Any way I look at it, I need to pull the runners and redo the seal...just wondering if this is a better solution...
The reason is my front drivers side pair has started to suck external air...I've snugged the bolts and it is still doing it. New gaskets are gonna be a PITA as my large-bore runners and siamesed manifold don't exactly conform to any of the "standard" manifold gaskets.
Any way I look at it, I need to pull the runners and redo the seal...just wondering if this is a better solution...
Drifting
Joined: May 2002
Posts: 1,509
Likes: 3
From: Hazel Park MI
I have AS&M runners & a siamesed stock manifold, and I used the runner gaskets AS&M provided. I just fabbed to the siamesed manifold - cut them where they should be cut to not impede airflow - and all was well. But, I was not as careful as I should have been doing the siamesing, and I nicked the outside edge of a manifold port. It led to a nasty vacuum leak, that a little permatex fixed. Do it if you have to, but get gaskets and add permatex if needed. TPIS sells large tube runner gaskets that you can fab to fit. Good luck. 
Race Director
Joined: Feb 2004
Posts: 12,518
Likes: 19
If you are considering using some kind of rtv silicone sealant instead of a gasket. I would not. The bond created will make dissassembly in the future very difficult. Difficult enough that you could bend or break the runners during the future removal. If you are asking about sealant on the gaskets, if probably cannot hurt. I always use new gaskets with a thin coat of dielectric grease on them. Has always worked out fine for me.
Drifting
Joined: May 2003
Posts: 1,979
Likes: 48
From: Lakeport CA
Last set of TPIS large tube gaskets I bought, wasn't really happy with. They were VERY skimpy on the material, almost like they had stamped out a larger inner hole in a stock gasket, leaving little behind. They worked but I used a very thin layer of sealant to insure no leaks.
