Kurt
Well-Known Member
- Messages
- 958
- Location
- Orange County, CA
Technically speaking a liquid/liquid heat exchanger (piping one coolant/fluid through another) is more efficient than air/liquid heat exchangers (ie. grilled/fin radiator). I've seen some nice cooling setups on trophy trucks and race cars where they run engine oil into a dedicated heat exchanger unit [basically a "box" filled with the coolest engine coolant in the system, usually coming out of the radiator, being run through a series of plates connected through a pipe of whatever you want to cool [most common I've seen is engine oil -> engine coolant exchangers].
Now whatever it's worth it to run transmission fluid through one? I guess it depends.
I know on the H1, transmission temperatures are rarely a problem, it runs super cool due to the finned oil/transmission cooler in front of the radiator. The only time I can get transmission temperature to get anywhere near 200 is if I'm low gearing it off road downhill over a long grade. Now if I ran that through the engine coolant, I'm going to be looking at transmission temperatures of 200-220 all the time because now the transmission fluid will only be as cool as the coldest point in the engine cooling circuit. The upshot of that is that you are transferring some of the engine coolant heat into the transmission fluid side. The downside is you are raising the "floor" of your tran temp up. Any H1 owner who installed an intercooler and relocated the oil/transmission cooler to behind the radiator will have noticed this effect.
The idea is to shed as much heat out of the system as possible. And it'll depend on the layout of the vehicle. AM General started using more and more of the liquid heat exchangers on the H1/HMMWV as time went on. The Alpha started using engine coolant cooling for the transfercase, and the latest revision ECV hmmwv's have engine coolant heat exchangers on each differential as well. I didn't think differential cooling was a huge issue on these trucks, but maybe the reason is the opposite, stuff as much excess engine heat anywhere else in the system where you can.
Btw that's a great looking radiator. I'm assuming the OEM one was a 4 core copper/brass unit with plastic tanks, and the new one is a dual core [larger tubes] unit?
