Reverse coolant flow Chevy big block

[Bob Hollinshead]

I was told awhile back some have been converting the Chevy big blocks to reverse coolant flow. What's the advantages? How is it done?

[pamotorman]

I was told awhile back some have been converting the Chevy big blocks to reverse coolant flow. What's the advantages? How is it done?

GM tried it on a small block but they got sued by someone who holds the patents on reverse cooling so GM dropped it. cooling the combustion chambers first seemed to allow higher CR without detonation. some sprint car engine use a block center feed to get more even cooling of the heads for the same reason. if I remember correctly some old GM engines had the water pump input flow directly into the heads instead of the block

[Schurkey]

Early Pontiacs were reverse-cooled with their "Gusher" cooling system.

I don't know how whatzizface can hold patents on reverse cooling when GM themselves did it from '55--'59.

[andyf]

Backyard reverse cooling is a bad idea. Maybe if you can get help from someone who has done it for awhile and knows what they are doing then go for it but I wouldn't do it on anything other than a drag car and even then I probably wouldn't mess with it. You'll have a very difficult time getting air out of the heads when you reverse cool and if the air pocket ends up in the wrong spot then you'll burn something up.

I reverse cooled my Mopar big block for a while but then I decided it was a dumb idea so I went back to a conventional water pump. Never saw any difference in power or anything else but the risk of getting an air pocket in the head and cooking a cylinder seemed too big for me.

[peejay]

Why would you need to mess with reverse cooling for a drag car? I'd think you'd want it for applications where you bolt the throttle to the floorboard for minutes/hours at a time.

Kind of like the Pontiac V8 actually. I think the BMW M engine also sent coolant in to the exhaust side of the heads first with an external manifold, will have to look it up. I don't know alphanumeric secret codes, I'm thinking of the 3.5l engine they designed in the 70s for road racing, that was the engine in the M1 and got turned into a four cylinder for the original M3.

[turbo2256b]

There are many versions of coolant flow through an engine and variations of each. Some of the best designs were back in the much older engines due to the quality of fuel back in the early 1900s up until octane ratings improved cooling systems went down hill a bit after that. In a well designed system there is only a couple degrees difference between reverse cooling and standard.