Novusuhu

Hey guys

What's a good gasket for the waterneck on a sbc?
It's a chrome waterneck and an aluminum intake.
Do I have to use sealant on the waterneck base or not?

jackson

Most "chrome" waternecks are asian junk ... on most of them, the "flat" surface is Not flat because the cheaply cast piece is warped when new.

first check it by putting very fine sandpaper on a pane of glass ... slide the WN across to & fro ... a pattern will reveal warpage ... keep sanding until level.

System runs well below 20 psi ... if it's flat, any gasket will do. I like Permatex #2 in a tube ... it's Not silicone.

resdoggie

If the mating surfaces are true, a paper gasket is all that is needed.

Novusuhu

What gasket do you prefer?

derekderek

blue felpro

stumpshot

Just as an aside--- my father used to make all his low pressure water gaskets out of old shoe boxes. Cut em out, punch out the holes and paint both sides wirh copperkote. Allways worked for him!

dmaxx3500

paper gasket and peratex on both sides

and throw the fancy chrome neck in the trash

just use a cast one and paint it chevy orange or silver

7T1vette

The problem with sealing on chrome surfaces is that they are too smooth and slick. If you are going to put a gasket on that surface, you first need to rough up that surface with some 240-320 grit paper. Scuff it in multiple directions so that there are little grooves for the sealant to fill and bind to. DO NOT USE SILICONE SEALANTS....except for Permatex Ultra Black RTV. My preference is Permatex #2 gasket sealer. Let the joint sit overnight before you fill with coolant and/or operate the vehicle. It'll seal....

resdoggie

This.

Buccaneer

If you use a blue FelPro gasket, you DO NOT need to use any sealant. It will seal just fine dry. However, this is a great gasket as well and IMO better. Cometic Water Neck Gaskets C5538-047 $1.99 ea.
Summit Racing

Big2Bird

And reusable. If your stat gets stuck on a trip, yank it out, bolt it back and drive on. Wanna flush the block, just do it, and re use it. If it leaks someday, get a new one. BFD.

derekderek

$2.99

Novusuhu

Will the cosmetic gasket also work well on an aluminum surface? Because I've read that sometimes people have trouble sealing an aluminum surface.

derekderek

when in doubt a thin skin of RTV.

lars

There is no problem sealing on a flat aluminum surface. The problem is the chrome waterneck. Sand or file all of the chrome plating off the sealing surface of the waterneck - down to bare cast metal. It will then seal up just fine with the FelPro blue gasket - with or without sealants.

Lars

Roy W.

There was no mention of the chrome plated steel thermostat housing which uses an O-ring instead of a gasket. Good or bad ??

HeadsU.P.

I agree with Lars. You can make the chrome units work and you don't need to throw them in the trash. The chromies just need a little tweaking.
<<<<<<<<<<<<<<<<<<<<
See the chrome on the left?
No leaks!

And the "O" ring units are common with the swivel style of housings.

DAD111

Most of the chrome ones i have used have O-Ring gasket - Never had any issues

Buccaneer

^^^THIS^^^

Both gaskets work great and no sealants are necessary and that's even coming from FelPro. I like Cometic gaskets and use them on a lot of things on my motor. They have Kevlar in them...I also like their MLS head gaskets, but they are NOT cheap. I like the piece of mind knowing they are superior gaskets and good insurance. There are plenty of good gaskets out there, but I'm just partial to Cometic.