Russell Kent wrote:

Monty Roberts wrote:

If sized properly, the oil/water exchanger will absorb enough heat.

You mean "if sized properly, the oil/water exchanger will cool the oil

sufficiently."  Nobody disagrees.

The temperature of the H2O/glycol coolant entering the main radiator

is also increased when using a water/oil exchanger, thus increasing delta
T and therefore main radiator efficiency.

Yes, the oil/water exchanger increases the delta T at the water

radiator.  Yes, increasing the delta T will increase the BTU/second
transferred (all other variables held constant).  The question is: what
will the water temperature be at the radiator outlet?  You see, the
radiator's BTU/second transfer rate increases as the air/water delta T
increases, *but* that

increase does not keep pace with the water's increasing BTU

*content*.  So your radiator outlet temperatures could be too high,
meaning you have to change some of the other variables (more air or a
different [larger] radiator).

Less ducting and plumbing means less weight/drag and complexity.

Therefore, this is the design I will pursue.

Be certain to size your ducting and radiator to transfer the combined

heat load (coolant & oil).

Russell Kent

One third more (area, volume, air etc.etc..) for the main rad. There is no
free lunch.

Paul Lamar

Greg Richter wrote:

There is an easy qualitative method we can use to explain this.  If you
transfer *all* the heat from the oil to the water, now we have to cool the
water.  Which means a larger radiator.  I tried the Aeroquip cooler, which
is for sale cheap if anyone wants it.  It cooled the oil, but nowhere near
enough.  If you can make this work, please let us know the details.  It
_should_ work out, but it'll take some development.

-GR

 
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