sbc rear intake manifold oil leaks

[Mike Savelle]

whats the best to seal the intake ? I've been using red silicone for years , but the last two engines have leaked badly , I Even redid it and it still leaked, is the red silicone no good ?

[JP1738]

Originally Posted by Mike Savelle

whats the best to seal the intake ? I've been using red silicone for years , but the last two engines have leaked badly , I Even redid it and it still leaked, is the red silicone no good ?

I was having this issue on my super gas sbc. I used black gasket maker (Permatex) and smeared it liberally across the back of the china wall after a thorough cleaning. Hasn't leaked since.

[JP1738]

Well at least it doesn't leak out of the back of the manifold anymore. The engine leaks like a sieve, just not from there lol.

[cad]

Ford TA-31 RTV silicone. Ive used it for years.

https://www.amazon.com/Genuine-Ford-TA-31-Silicone-Sealant

[Mark Ugrich]

G.M. 10-2006 engine sealant is good stuff also.

[Henrys Toy]

Originally Posted by Mark Ugrich

G.M. 10-2006 engine sealant is good stuff also.

Good morning to all,
I've been using the Permatex " Right Stuff " for a couple of years now.
The engine in my Suburban I recently went over the valve adjustment and found a couple of wet area's on the valve cover gaskets - I cleaned and used the Right Stuff on them and that oil leak is solved. No more oil smell while sitting in traffic. I use that on all my small block and big block china walls - zero leaks. It dries quick enough while dyno testing as well. I also use the Permatex Grey silicone with great success as long as you have time for it to properly cure. Make sure the surfaces are CLEAN and OIL FREE.
I found that to be very important in the curing process.
I hope that helps.

Respectfully,
Henry Kunz 1534 H/SA

[1320racer]

Permatex Right Stuff!. I’ve never had an intake manifold, water pump, water neck leak on any engine using this stuff for decades and I’m convinced you could lift the engine from the intake manifold without any bolts in it.

[Mike Pearson]

permatex ultra gray here. Make sure its not the oil gauge fitting back there. There is no pressure on the back of the intake. Never had a leak there.

[Mike Savelle]

thanks for the ideas , will take it apart and give it a try ,

[pmrphil]

Yup, use the Permatex "Right Stuff" and install the manifold with it wet, don't let it "skin" over. It won't leak.