Radiator Tranny Cooler

Route666

Active Member
Aug 16, 2003
1,652
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Brisbane, Australia
I did a bit of a search but came up with nothing.

For this topic, say an electric fan cooled aluminium radiator with a 160* thermostat is being used on a 400hp 331. Temp range is winter: 40*F coldest and summer: 105*F absolute MAX.

What problems would one uncover if they tried to use a radiator tranny cooler as an engine oil cooler? (Using a manual trans)

Would the input and output fittings be too small to flow enough?

I can't think of anything else that would be a problem, since the radiator is on the OTHER side of thermostat it should stay at or below what the thermostat opens at right? Could the oil get TOO cold?


EDIT: Ok I've thought of a couple of other things that might be bad.

1. If it corrodes, water can get in the oil.

2. The engine won't warm up as fast, unless you thermostatically controlled the flow to the cooler. - Although I think a seperate oil cooler would have the same problem, but not as severe.

Does that sound right?
 
while oil can get too cold, what you suggest will not be a problem as the oil temp will be maintained at what level the coolant temp is at. the other problem you have is you will be trying to route engine oil though tubes that were designed to handle a much lighter fluid. a better approach would be to use the oil cooler that was used on the special service mustangs.
 
I'm a little confused but think you want to cool your engine oil via the radiator (heat exchange).

If you want the heat exchange capabilities of oil/water cooler, you should purchase a unit that is dedicated for this purpose.

Fluidine makes several units: http://www.fluidyne.com/pl_thhe.html

C&R also makes purpose built radiators: http://www.crracing.com/
http://www.totalcontrolproducts.com/vehicles/tcpracecar/support/tcp79.jpg

I would NOT use a radiator designed for an automatic transmission.
 
So am I correct in thinking that you want to use the portion of the radiator for engine oil, that would normally be used for transmission fluid in an auto?

I think it'd work OK if you do not plan on running the car at below freezeing temperature.

I'm not sure what rbohm is thinking, but your oil temp would not be kept at the same temp as engine coolent inside of the engine. Depending on the circumstances, it could be significantly cooler. (Ie, in -10* weather).

True, you don't want your engine oil blistering hot. But you don't want it cool either. It's ment to run at or near engine operating temperature.

If you do decide to use an engine oil cooler, use a dedicated cooler with an electric fan. That way you can turn on the fan only when it's hot out, or even have it controlled by a thermostatic switch (it turns on when the oil going through the cooler reaches a certain temperature).
 
I believe transmission fluid is under less pressure (maybe 5-10psi), as where oil is in the 50-60psi range. Oil cooler kits usually have a themorstat built into the adapter to only allow oil to flow through the cooler when it is warm. Running your oil too cold is just as bad as running it too hot (different but bad). I would take a look at the size of lines run to an "oil cooler" and compare that to the fittings in the radiator....
 
66P51 and 70_Nitrous yep that was what I was asking about.

Thanks for the info, I should have realised there would be dedicated heat exchangers.

So the tranny exchanger lines are too small, under less pressure, and I don't feel that comfortable with oil and water coming in such close proximity.
 
Route666 said:
So the tranny exchanger lines are too small, under less pressure, and I don't feel that comfortable with oil and water coming in such close proximity.
Proximity isn't the problem. It just has to occur in a system that was designed for it. Use of Steel Braided lines is a must. I ran an external oil filter on one of my earlier builds and chassis vibration ended up chaffing the line and I ended up spraying oil in the engine compartment and eventually on my left front rotor (not fun).

One of the nicest designs I've seen is offered from Howe. I'll try to post some pictures of a similar unit installed on a Boss 302 track beast.

http://www.howeracing.com/Radiators/Index-CustomRadiators-Exchanger.htm
Exchanger.jpg


Also, unless you have excessive overheating issues and have a dedicated high-performance Track/Street car, I wouldn't worry about it.