Hello, I am new to this site and had a question. i have a 66 cutlass convertible with a 68 455 engine and the engine was running hot ( around 230 deg. ) also noticed bubbling in the recovery tank. pulled the heads and sent them out, no cracks or serious warping found. i noticed the engine block deck has some visible pitting and was wondering if i could apply a thin coating of sealant to the block surface to help seal the head gaskets. i realize that it would correct to pull the block and get it resurfaced but that is not in the budget right now so i'm looking for alternatives. any help with this would be appreciated.

 

Make sure the deck is CLEAN, CLEAN, CLEAN. Use a bottoming tap to chase all the threads. Then you can use this on the head gaskets during assembly.

https://www.summitracing.com/parts/ptx-80697

 

olds64 thanks i'll look into that. and I appreciate the quick response. Rex

 

Hal,
Depending on which head gaskets you are using you might make matters worse by using any type of coating. Most modern head gaskets have a coating on them that "flows" when it gets hot and helps to seal the gasket. For example the Blue coating on Fel Pro gaskets. If you put another coating on them it will affect the way the blue coating works.

Depending on where the pitting is it might not even be an issue. Can you post a picture ?

 

Hi Hal, I am using Fel pro gaskets and had not thought of that. I am guilty of over thinking things but didn't think of that lol. The engine didn't overheat badly was just running hot. when disassembling it i also noticed that the fans on the aluminum radiator where improperly installed and were actually rubbing on the radiator. ordered a new 4 core radiator and two 13" Spal fans with shroud for improved cooling. i just bought the car and didn't know much about it. it probably just needs new head gaskets. Thanks for bringing that to my attention. I'll know if that worked when i get it all back together. Thanks again Rex

 

Like you said, don't over think things. The Permatex copper spray I linked is designed specifically for head gaskets. I used it on the FelPro head gaskets that I installed on my 455 recently when it blew a head gasket.
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like BILLK said the felpro gaskets i'm using have that blue coating on them. are we talking about the same gaskets? are those the ones you used? I got a can of the copper gasket spray you recommended seemed like a good idea. i'll still use it if it will help and not hurt.

 

With Fel Pro's I always cleaned the surfaces with lacquer thinner after scraping with a razor blade scraper. I did not use any sealer on them. With Cometic multi-layer steel, I used K&W Koppercoat spray.

 

That is when you are using metal gaskets. The Fel Pro engineers would be having fits knowing that you put it on a "modern" coated composition gasket. I know you did it and didn't have problems and I have certainly seen other "old school" mechanics use it too but it is not recommended or needed.

https://www.felpro.com/technical/tec...clean-dry.html

 

I used the FelPro HS8171PT4 head gasket set with the Permatex copper spray.