thanks!
silicone on intake gaskets?
Thread Starter
Safety Car
Joined: Aug 2002
Posts: 3,791
Likes: 10
From: Long Island NY
silicone on intake gaskets?
i'm gonna fix my intake leak today and wanted to know if i need to use any silicone on the gasket itself? i bought them from the dealer so i guess they are GM LT4 gaskets.. i'm gonna use the Permetex "right stuff" to seal the front and rear..
thanks
vinnie
thanks
vinnie
Racer
Joined: Apr 2002
Posts: 342
Likes: 0
From: new orleans La
Originally Posted by BlkSS1755
i'm gonna fix my intake leak today and wanted to know if i need to use any silicone on the gasket itself? i bought them from the dealer so i guess they are GM LT4 gaskets.. i'm gonna use the Permetex "right stuff" to seal the front and rear..
thanks
vinnie
thanks
vinnie
Hey Vinnie, I'm in the process of doing the exact same thing on my rebuilt LT4.
My problem was a open loop idle surge, hunting idle and part-WOT stumble which turned out to be the intake gaskets not sealing on the bottom of the intake ports and as a result the intake was sucking in air and oil. I would recommend putting a very thin bead around the intake ports themselves.
Burning Brakes
Joined: Aug 2001
Posts: 1,238
Likes: 0
From: walled lake MI
i just went through this and after 2 gasket changes due to leaks by installing the Felpro gaskets dry, i installed a third set along with Permatex Black silicone adhesive sealant. i put the thinnest bead down i could possibly get. works fine now.
HOWEVER, i have been advised against using sealant from many on the Forum. our LT1/4 manifolds are dry and they *should* not need sealant.
another thing to note is that i found the Felpro gaskets were a few thousanths thinner than the stock gaskets, and the metal portion of the gaskets were considerably flimsier. i have not heard of any bad things about the Felpro gaskets but the dimensional/material difference might've been enough to make a difference in my particular case.
that all said, since you are installing a stock gasket i would install it dry. it will make it easier to change it again later, and you will not have to worry about stuff squeezing out in the ports. remember, clean all the gasket surfaces to a point you can literally eat off of it. i used a scraper, scotchbrite, then TB cleaner and rubbing alcohol to get rid of all residue.
incidentally, the right stuff for the front and rear seals work great.
HOWEVER, i have been advised against using sealant from many on the Forum. our LT1/4 manifolds are dry and they *should* not need sealant.
another thing to note is that i found the Felpro gaskets were a few thousanths thinner than the stock gaskets, and the metal portion of the gaskets were considerably flimsier. i have not heard of any bad things about the Felpro gaskets but the dimensional/material difference might've been enough to make a difference in my particular case.
that all said, since you are installing a stock gasket i would install it dry. it will make it easier to change it again later, and you will not have to worry about stuff squeezing out in the ports. remember, clean all the gasket surfaces to a point you can literally eat off of it. i used a scraper, scotchbrite, then TB cleaner and rubbing alcohol to get rid of all residue.
incidentally, the right stuff for the front and rear seals work great.
Racer
Joined: Apr 2002
Posts: 342
Likes: 0
From: new orleans La
Originally Posted by tempest
i just went through this and after 2 gasket changes due to leaks by installing the Felpro gaskets dry, i installed a third set along with Permatex Black silicone adhesive sealant. i put the thinnest bead down i could possibly get. works fine now.
HOWEVER, i have been advised against using sealant from many on the Forum. our LT1/4 manifolds are dry and they *should* not need sealant.
another thing to note is that i found the Felpro gaskets were a few thousanths thinner than the stock gaskets, and the metal portion of the gaskets were considerably flimsier. i have not heard of any bad things about the Felpro gaskets but the dimensional/material difference might've been enough to make a difference in my particular case.
that all said, since you are installing a stock gasket i would install it dry. it will make it easier to change it again later, and you will not have to worry about stuff squeezing out in the ports. remember, clean all the gasket surfaces to a point you can literally eat off of it. i used a scraper, scotchbrite, then TB cleaner and rubbing alcohol to get rid of all residue.
incidentally, the right stuff for the front and rear seals work great.
HOWEVER, i have been advised against using sealant from many on the Forum. our LT1/4 manifolds are dry and they *should* not need sealant.
another thing to note is that i found the Felpro gaskets were a few thousanths thinner than the stock gaskets, and the metal portion of the gaskets were considerably flimsier. i have not heard of any bad things about the Felpro gaskets but the dimensional/material difference might've been enough to make a difference in my particular case.
that all said, since you are installing a stock gasket i would install it dry. it will make it easier to change it again later, and you will not have to worry about stuff squeezing out in the ports. remember, clean all the gasket surfaces to a point you can literally eat off of it. i used a scraper, scotchbrite, then TB cleaner and rubbing alcohol to get rid of all residue.
incidentally, the right stuff for the front and rear seals work great.
Burning Brakes
Joined: Apr 2002
Posts: 934
Likes: 0
From: MO
I would use a thin coat. An engine builder friend of mine turned me on to eldelbrock "gasgacinch" (sp?) a long time ago to use around the intake ports when installing intake gaskets. Also its always a good idea to not start the car immediately after install. I wait until the next morning so the RTV sets up well then start.
Thread Starter
Safety Car
Joined: Aug 2002
Posts: 3,791
Likes: 10
From: Long Island NY
thanks for the good advice.. would it be safe to say, no silicone for OEM GM gaskets, and a small beed around the intake ports for aftermarket gaskets (i.e. felpro, etc.)? the reason i'm so concerened, is i have little time with work and everything, and would like to do it right the first time..
thanks again,
vinnie
thanks again,
vinnie
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Racer
Joined: Apr 2002
Posts: 342
Likes: 0
From: new orleans La
Originally Posted by BlkSS1755
thanks for the good advice.. would it be safe to say, no silicone for OEM GM gaskets, and a small beed around the intake ports for aftermarket gaskets (i.e. felpro, etc.)? the reason i'm so concerened, is i have little time with work and everything, and would like to do it right the first time..
thanks again,
vinnie
thanks again,
vinnie
