Anyone running Cometic head gaskets?

[SSMAN]

I had some installed and all is good except for a pesky intake leak. Both front and rear. I had this done by a guy that does all the work, I don't do on the car. I have no doubt that he can seal an intake. But after two attempts, it leaks front and back?

No gaskets front and rear, just Permatex black RTV. Plenty of bead on there. He worked on my mustang and my camaro and until now, never had an intake leak. I will say this is a bad leak in my opinion. Not fogging the neighborhood bad. But park the car for an hour and have two 8" dia oil spots.

Is there anything about the Cometics that would cause this? I did go with a thinner head gasket (.027), other than that all is the same. Any constructive input would be appreciated. TIA

[Lason]

install error. There is no way the head gaskets will cause front and rear intake oil leaks. The guy isnt using enough silicone.

Did this same setup seal with different head gaskets?

[VaderTT]

I had them on a 302 no leaks.

Used, copper spray, indian head sealant on the bolts that hit water passages and high temp rtv for the intake front and back. I can remember the torque settings but I had thenm written down some where.

Sealed like a charm.

[SSMAN]

install error. There is no way the head gaskets will cause front and rear intake oil leaks. The guy isnt using enough silicone.

Did this same setup seal with different head gaskets?

Well, that is what I was thinking , but the damn RTV is bulging out just fine. I have set many of intakes and this appears to be sealed good. (Except for the leaking) It's in for the third time to be sealed, we will see how it goes.

It leaks from the front left side, can't tell exactly where on the rear. But it is a big leak. Every time I run it up to 6k plus, it's pouring out the front and rear.

[greenbullitt]

cometics require a specific deck finish to ensure positive seal. Why would you put cometics on a street car anyway? I like having a fuse to protect my pistons...just my .02

[Bottlefedstang]

Hurt motor to much crankcase pressure.

[SSMAN]

cometics require a specific deck finish to ensure positive seal. Why would you put cometics on a street car anyway? I like having a fuse to protect my pistons...just my .02

Blew a head gasket with a little 125 shot. Everyone told me they were the best. It does get driven hard. But I hear what you are sayin. Heads are sealed good, it's the intake that is giving me trouble. We will see what happens after this latest reseal.

[SSMAN]

Hurt motor to much crankcase pressure.

Compression and leak down test is all good.

Keeping my fingers crossed for just a freak leak. Never had an intake leak issue with this car before.


Thanks for everyone's input.

[shumpertdavid]

Excessive blows by / crank case pressure?

[turbostang]

You're saying the headgaskets are now cometics and the intake is leaking?

There's two possible scenarios -

One, it's not the intake, but the upper ends of the HG leaking the oil. Been there, done that. I usually pry the gasket apart and put sealer between the layers (very small amount).

Two, it's actually the intake itself leaking in the corners of the endrail. As common as you can get on a SBC. My take, that black RTV is junk and never had any luck with it. I'd be using the perma black, blue or copper. If you feel like welding your intake down use the ford diesel silicone.

[SSMAN]

You're saying the headgaskets are now cometics and the intake is leaking?

There's two possible scenarios -

One, it's not the intake, but the upper ends of the HG leaking the oil. Been there, done that. I usually pry the gasket apart and put sealer between the layers (very small amount).

Two, it's actually the intake itself leaking in the corners of the endrail. As common as you can get on a SBC. My take, that black RTV is junk and never had any luck with it. I'd be using the perma black, blue or copper. If you feel like welding your intake down use the ford diesel silicone.

I thought Perma Black , was Permatex Black gasket maker?

Interesting about the head gasket thought you have. Will have to check it. Thanks Brooks.

[juiceweezl]

I have cometic gaskets and no problems.

[turbostang]

I thought Perma Black , was Permatex Black gasket maker?

Interesting about the head gasket thought you have. Will have to check it. Thanks Brooks.

there's two kinds of each sealer from permatex.

Regular blue RTV (translucent blue) vs. Ultra blue (metallic blue in color)
Regular orange RTV(translucent orange) vs. Ultra Copper (metallic copper)
Regular black RTV (translucent black) vs. Ultra black (metallic black)

Ford diesel - grey in color, and made from materials not known to be found on planet earth.

The layers of the cometic I speak of sealing are only in the upper corners of the gaskets fwiw.

[Lason]

Only two RTV's I use are ultra black and ultra copper. Ultra Copper for exhaust and Ultra Black for everything else, that stuff is great. Never used the Ford stuff though.

[turbostang]

Only two RTV's I use are ultra black and ultra copper. Ultra Copper for exhaust and Ultra Black for everything else, that stuff is great. Never used the Ford stuff though.

It's expensive by comparison, but damn - It's seriously hardcore. Something like 25$ a tube.