I finally found a math model that provides the rise in temperature as it
goes through a radiator.  The model indicates that for the two evaporator
cores that the air temp should rise between 35F and 38F for 161 HP at 120
MPH burning 15 GPH.  Less of a rise if less BTU are being generated.

Here is what the temp rise model gives (all temps in farenheit):

OAT  Delta T   Exit Radiator

0            34.9        34.9

30            35.59    65.59

60        36.15        96.15

90        36.02        126.02

120        37.48        157.48

I guess I am surprised to find that the delta T is decreasing with
decreasing OAT. The only way I can rationalize the lower delta T at the
lower temps  still removing the same amount of heat is that the cold air is
denser and therefore  the mass flow is greater and that accounts for carring
away the same amount of heat with a lower Delta T.  Would any of your
thermodynamic folks comment on this?

In any case, it appears that some of Todd's delta T figures fall in this
ball park, so this model may not be too far off.


Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com