LS intake sealing

[Walter R. Malik]

I had an issue with vacuum leaks at the intake / cylinder head junction when using the "O" rings.

The groove in the intake runner faces, around the ports is .093" deep and .135" wide and the "O" ring is .101" thick for only an .008" compression ... anyway, they leaked vacuum.
I got some SCE intake gaskets for this L92 application ... my question is; should I fill these grooves or, just use it the way it is or, put the "O" rings in it to take-up the space and let them ride against the gasket port opening ...?

Is there a thicker "O" ring for this application, which is readily available ...?

[swampbuggy]

Hello Walter: If it was my stuff and the said Gaskets fit good, i would as you mentioned fill the grooves with your favorite epoxy. Of course over filling the grooves slightly and then carefully file the epoxy flush with a Mill-Bastard file . Mark H.

[Dave Koehler]

Checking a different brand of o-ring might prove interesting.
I would use the o-rings with the gasket just in case a solution is discovered.

[Walter R. Malik]

Checking a different brand of o-ring might prove interesting.
I would use the o-rings with the gasket just in case a solution is discovered.

The ones I have are directly from General Motors; I have been told about some from McMaster-Carr which are .139" thick so, I will investigate.

[Walter R. Malik]

Checking a different brand of o-ring might prove interesting.
I would use the o-rings with the gasket just in case a solution is discovered.

The ones I have are directly from General Motors; I have been told about some from McMaster-Carr which are .139" thick so, I will investigate.

YES - McMaster-Carr has several; Buna-N; Viton; High Temp Silicone and others in all different sizes and thicknesses.

[novafornow]

My experience with O-rings says the .139" won't work. You generally need room for it to crush. .125" should be available and have a better chance of success.

[Dave Koehler]

But 1/8" o-rings actual size is .139. Such is the way, at least from MCM.

These folks have all kinds of diameters and durometers.
https://www.theoringstore.com/store/ind ... s_id=24348

[novafornow]

Try 3mm.

[Walter R. Malik]

My experience with O-rings says the .139" won't work. You generally need room for it to crush. .125" should be available and have a better chance of success.

There will probably be room to crush with a round ring in a square groove.

I am certainly going to find out.

[novafornow]

I urge you to look for 3mm first. O rings too tight can crack metal. Been there, done that.