Al,

How well does your engine cool on the ground?  What is the max rpm that your coolant temp will stabilize within your upper limit and what is the temp at that rpm? 

Do you have any fans or otherwise pulling air thru the radiators when sitting on the ground? 

 

It cools well enough; better now than before the cooling system mods.  I do have an auxiliary fan that draws about 800-1000 cfm through the rad that is in the cowl if I need it. The negative pressure from the prop also draws a reasonable amount.  Prior to the mods I could sit at idle for extended periods on an 80F day with the fan on.  Running at higher powers limited the time, usually the oil temp was limiting.  I know it cools better now on the ground, especially the oil, but I don’t have any hard numbers.  I recall my first test after the mods I ran for about 5 minutes at 2500-3000 rpm to get it up to 180F.  OAT was probably in the sixties, but I was surprised.

 

Tracy tells me that I should be able to run 2600 rpm or so and stabilize under 230 degrees on my Renesis, but it is not happening. 

I guess with the prop in front, that’s a reasonable expectation; probably not with the prop in back.

 

Al