I don't recall the exact size.
Here is a test rig I used to verify K&M findings.
I guess this was before your time.

Paul Lamar

I was here, but had just started and my mind was elsewhere.
The more I study the info presented the group the higher
and higher priority I've been placing on the radiator layout!
The VAN BOMB box was a great practical test solution!
I am trying to workout the sizes and desired esthetics before
building the test fixture. Bill J

 
The AirCraft Rotary Engine NewsLetter.  Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/            
Copyright 1998-2003 All world wide rights reserved.