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engine temp now hotter with 3800 stall

970 views 3 replies 3 participants last post by  xntrik 
#1 ·
I moved up to a YANK 3800 stall converter from a 3200 stall. My SBC 355 used to run around 197 *F. Now I run around 202-211 intown and 195 on the freeway. I am switching to AFR heads very soon. Can I expect a decrease in water temp when I switch to aluminum heads compared to my current steel heads? And how much cooler will it run by switching to a aluminum radiotor compared to my stock radiator.


Car is a six six Impala......

Thanks....

Dave
 
#2 ·
Higher stall creates higher transmission heat. If you have a system that has the trans cooler inside the radiator, higher trans heat will make the water in your radiator hotter. A solution would be to bypass the trans cooler in the radiator and mount an external trans cooler in front of the radiator.

I doubt that aluminum heads will have much effect on engine temperature. While aluminum heads do dissipate heat faster than cast iron heads, I don't think there will be enough difference to create a noticable change in engine operating temperature.

Here is a side note which you may already be aware of. Due to the fact that aluminum has a greater expansion rate, and also because aluminum dissipates heat faster, unless your new aluminum heads have more compression than your old heads, you may not see any increase in performance. Aluminum heads need to be at least a half a point higher in compression just to equal the compression ratio on cast iron heads.
 
#3 ·
Thanks for the reply. I currently have the trans line going into the radiator then into a trans cooler. I think I will by pass the radiator and get a biger trans cooler with its own fan...

Here is a side note which you may already be aware of. Due to the fact that aluminum has a greater expansion rate, and also because aluminum dissipates heat faster, unless your new aluminum heads have more compression than your old heads, you may not see any increase in performance. Aluminum heads need to be at least a half a point higher in compression just to equal the compression ratio on cast iron heads.
I am going from 1967 Camel Hump 2.02's with 64cc to AFR's new 2006 casting 195 Comp heads with 64cc. If I loose a half a point I will never notice it with the new heads and new Air Gap intake.. I am looking at a easy 75 HP bolt on from my current setup....:thumbup:

Thanks again....

Dave
 
#4 ·
More power equals more heat. True most of it goes out the exhaust but still there will be more heat transferred to the coolant due to the fact that there is just more total heat and the fact that the heads are aluminum.

Only time will tell if your cooling system will be adequate.

I don't see a problem with the temperatures you are running now, except

that more COOL air flow at lower speeds is indicated. Be sure the fan cannot suck hot air back into the front of the radiator at low speeds.
 
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