To seal or not the intake to head coolant ports?

[brown7373]

I am installing my intake on a new 350 crate engine. Should I use a sealer around the coolant ports? There was sealer on my old engine. If so, what sealer is recommended?

I am also reading that just about everyone junks the front and rear rubber gaskets for the intake and uses a silicon sealer. Is that recommended, and which sealer for that?

[PTC002]

The front and rear gaskets are prone to leak. Use silicone and be sure to lap up over the edges of the head gaskets. This is pretty much leak proof. Did not recall using any type of sealer around the coolant ports....but I have slept since then!

[rudykazoo]

On the coolant ports, I have always used old school brush-on Permatex. Just put a thin coat on each side of the gasket.

[6768chevylover]

I put sealant on the water ports all the time when I do intakes. I use the Right Stuff from Permatex which you can get from any parts store. Reminds me of a cheese wiz can..

[brown7373]

Thanks for the replies.

[GRX]

Originally Posted by rudykazoo

On the coolant ports, I have always used old school brush-on Permatex. Just put a thin coat on each side of the gasket.

^^ that.
Brown Aviation Form-A-Gasket specifically.

[clay68c10]

Yep, the Aviation gasket stuff is great. Best thing in the world for cork gaskets also.

[demian5]

And to protect the bottom of your intake port gaskets from leaking due to hot oil, you can put a light skin on the bottom edge on both sides. Old racers trick.

[67ChevyRedneck]

I did an intake 3 years ago by using permatex (black?) around the water jackets (both sides - just a light skim coat) then a thick 1/4"+ bead on the front and back. Let it get a tacky "skin" on it. I then torque in sequence to half spec the first time (should be available somewhere online, usually from the center out), then full the second time. Let it sit overnight and do it again the next day. I pulled that intake off recently to replace it with a 4 barrel and not only did it pop off cleanly, but the gaskets looked new still. Made putting the 4 barrel on much easier.

*ALSO* TEST FIT everything. Couple problems I've run into (on Ford and GM) - The new intake had tabs that hit my valve covers (on SBC). WAY easier to grind off when it's off the motor. An aftermarket intake was "taller" than my stock one so the intake bolts were too short (on a SBF). Distributor hit (again, on a SBF).

So, just dry fit everything and look for problems.