Tube style oil coolers?
 

I use to help work on my family's boat as a mate and Go-fer. I got to help my pops rebuild the three 1692 engines, this was around 6 or 7 years ago. I was about to flame another topic and i started to think about the tube style oil coolers that the detroits use. Instead of running a air cooled oil cooler, how about a water cooled oil cooler.
Let the flames begin.

http://www.hardin-marine.com/c-731-t...l-coolers.aspx

They have been discussed but they complicate things and the factory coolers are really quite good. I looked at a lot of options and have had two different cooler setups. But really all that is needed is proper lines and a proper oil thermostat.

The water available in most cars is fairly hot, often around 90°c. Ambient air vs 90°c water, what cools better?

A water cooled system would be a heat exchanger for the most part. You'd be making the water hotter to cool the oil (yet their temps are often very close to each other). Not an ideal solution especially when considering overall efficiency and system complexity.

Thanks for the input guys. Ill take 9ks word and work on getting a oil temp gauge to monitor for now. Ive been worried about actual temps of the oil and coolant. Im use to running my haltech e8 with my mini laptop in my rx7. After monitoring my temps ill make a decision.