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Cometic Head Gasket Cooling System Mod?

 
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MikeJinCO  



Joined: 08 Jun 2010
Posts: 704
Location: Maysville, Colorado

PostPosted: Wed Mar 07, 2018 1:50 am    Post subject: Cometic Head Gasket Cooling System Mod? Reply with quote

I dug out my Cometic head gasket to look at the cooling passages as there is some minor corrosion to the head and got a shock.

First a review the cooling system design. The water pump sends water into the block where it then filters up out thru the front of the head with a rear exit also for the heater and a small bypass to maintain flow. This results with an unequal cooling of the back to the front and subsequent piston problems in the turbo due to the heat. The GTR even went to a separate cooling system for the head.

The standard head gasket besides small cooling ports on each side of where the cylinders approach has an approximate 8mm hole on each side of the front 2 cylinders, an additional 3-4mm hole on #3 and larger openings on #4 and the main returns at the back.

The Cometic has no holes for #1, 2 2-3mm holes for #2 , a 6mm and 2ea 2-3's on #3 and probably an 8 and a 10 for #4, then the mains in the back. Both have a larger cooling passage in front by #1 and all those dimensions are eyeball approximate. Obviously an attempt has been made to reroute the water flow.

So the questions are. Did someone here help them design this? Was it one of the early performance engine builders? Does it work?

Then secondly in my case where there is no heater due to a track car. Do I need to even bother with the rear exit. The temperature gage due to different pipe threads will go in a water line, and the CIS cold start valve is gone. My original plan before seeing this head gasket was to block off the bypass and reroute the heater back to the water pump. I could still do that, but maybe sneak in a valve in case needed or just eliminate that line entirely and block off the water pump inlet.

Any thoughts, questions, on comments?
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Mike
Poco a Poco, '80 future track car
'77 924
cricketdesigns.com
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MikeJinCO  



Joined: 08 Jun 2010
Posts: 704
Location: Maysville, Colorado

PostPosted: Wed Mar 07, 2018 1:53 am    Post subject: Reply with quote

I should probably add that the Cometic does have the small ports where the cylinders meet on each side.
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Mike
Poco a Poco, '80 future track car
'77 924
cricketdesigns.com
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