Gordon,

     Unless you used a  pressure restricted bypass of engine oil to the trans cooler part of an auto

radiator this would not work very well.............Besides being very restrictive (not designed for the

volume of oil flow that a 13B puts out) these in-radiator trans coolers were not designed for the

pulsating pressure of the 13B oil system (plus auto trans oil is about 10 wt as opposed to 40 to

50 wt typically use in flying 13B engines)....................IMHO

Kelly Troyer

Dyke Delta JD2 (in progress)

13B/Turbo  

On Wed, Mar 7, 2012 at 2:33 PM, Gordon Alling <gordon@acumen-ea.com> wrote:

Yes, I'm running two 13Bs.  One rule of thumb I use is for a typical gas
engine, the total fuel energy is distributed roughly 1/3 to the shaft, 1/3
to the coolant and 1/3 to the exhaust.  Assuming an even 200 HP shaft power,
that puts approximately 200 HP = 510,000 BTU/hr into the coolant.  I don't
know how this distribution changes for a rotary vs. a piston engine.  My
approach is to look for an automotive radiator for an engine with roughly
the same shaft power as the 13B and see how it works.

That aside, I noted that several of the auto radiators that I am looking at
integrate an oil cooler for transmission fluid and/or engine oil.  This
strikes me as rather slick if the ratio of radiator area to oil cooler area
works for the distribution of cooling load in the coolant vs. the engine
oil.  Assuming that 1/3 of the cooling load is in the oil, as a starting
point, I will look for a radiator that has 1/3 of its face area dedicated to
oil cooling.  In the end, I will have to test is and see.

Thanks for the input.