X-Mozilla-Keys:                                                                                 

charles.harbert wrote:

Paul, I though about using a combination water/oil cooler, but decided 

not to

because of the following reasons:

1. You are always going to get a much higher delta T from the air stream 

than

from the water. Thus you'll need a much greater surface area to obtain 

the same

cooling. I think you would end up with a larger overall cooling system 

using

this approach, plus trying to balance the 2 cooling requirements might 

be

problematic.

2. The oil pressure is much greater than water pressure and if you get a 

leak it

will go into the water system which is better than the other way around 

(other

than if you circulate water thru tubes in the oil pan). However, oil in 

you

water is not good either, so I felt it was better to keep them totally 

separate.

3. Most race cars have separtate systems, and Mazda kept them separate.

marc mularz wrote:

Charles:
I agree with you on reasons 2 and 3 but I'm not sure how to evaluate reason

1.  Water conducts heat approximately 26 times better than air if my memory
serves correctly.  This would mean that a smaller delta T win the water
cooler setup could still be quite a bit more efficient than using air.
Further thoughts anyone?
Marc M. 

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