Posted for "Ed Anderson" <eanderson@carolina.rr.com>:

Neil's radiator was 6" thick which may have been a bit too thick.  Also,
Neil has his radiator install a la P51 Mustang style which may have had
something to do with it.  He never flew with that installation, so don't
know how it may have done with more airspeed.  But, I must admit I would be
hesitant to go thicker than 4" depending on the fin density.

Since, a number of us have sucessfully operated with the GM evaporator cores
3.25" thick and the fins are packed denser than a normal radiator, I would
think that any thickness up to this should be OK.  Perhaps not optimum, but
I don't know how what optimum would be.  While not a precise data collection
method, I have held my hand behind the 3.25" GM cores and with the prop at
idle, there is a great deal of hot air exiting the radiator.

It would be great if we had a wind tunnel to see what a optimum
width/thickness ratio might be from say 80 - 220 mph.

Ed Anderson