Ran 1st race at Willow in my 20b NA PP GT1.
Oil temps 220-245 deg F. Air temp 80 deg F.
Using Hayden #1260 12x24x1.5" rated at 28-44,000 BTU.
Radiator behind cooler running at 160 deg F all day.

Can't find BTU rating on other coolers, except Long 11x11x1.5" at 29,000 BTU.

What works for you?

Wayne G running similar 20b setup with Mazdacomp oil cooler had similar temps.
Mazdacomp cooler no longer available.

Looking for better cooling.

Rating should be at specified oil flow and specified air flow, with graphs. These numbers just can't be found.

 

I run dual 25 row "wide" coolers (13 x 7.75 x 2) each rated at 57000 BTU, on a GT42RS 20B.

Earl's oil cooler BTU data, and testing against tube and fin

http://www.earls.com.au/files/496438...OILCOOLERS.pdf

Setrab BTU data http://www.setrabusa.com/products/oi...ine/index.html