Hi friends I have to install an copper head gaskets in a big block chevy. can I use another sealant than hylomar? maybe hi- tack permatex or other brand or type? happens in PR its difficult to get. Thanks Angel

I have copper gaskets with o-ring/receiver groove and I used copper coat in a spray can last time and it didn't leak a drop. That's a BBC with alum heads on iron block, high pressure cooling system (22psi cap). I also used a very thin cirle of "right stuff" RTV around the coolant holes on both sides of the gasket. Too much and it will spread and block the holes.

The best bet is to pressure test the cooling system after assembly before putting it in the car (I found another leak - pan bolt hole) then retorque the studs after it is fully cooled from the initial warm up.

I have a can of hylomar for next time as it supposedly works better. I had to special order it as it is largely unavailable in Canada also. I heard that the factory Mopar stuff available at dealers is basically Hylomar - can anyone confirm this?

How are you going to presure test it? :rolleyes:

With intake on or off?

With intake on - simply attach radiator to engine and use standard cooling system tester that goes on rad cap, pressure up to 20psi with air and see if it holds! Better yet, fill the system and test with water.

With intake off - make block off plates for the water holes, bend over upper rad hose and put a pair of vice grips on it and test through radiator. (this is how I do it every time)

Or easier yet w/o intake or rad, block off intake and block off water pump holes and weld a pipe bung or tap threads into one of the blockoffs to plumb the pressure tester into it.

It's easier to find out if you have a plug or gasket leaking before putting the engine in the car and trying to find where the water is coming from...

Any more questions? :rolleyes:

under construction http://lumpracing.com

Ryan, I checked out your seb site, very cool. The inside scoop says Edelbrock is going to debute an 18* BBC head at PRI. No word on runner size or any other details.

John