Fred wrote:

 

I'm try to collect info about the best option for selecting an oil
cooler for my 20B.  Have been hearing a lot of bad things about some
after market brands used on the rotary.  What about two 13B oil coolers?

Two 13B coolers would work (with a margin of safety) if you have the space to put them.

I got a custom oil cooler from Griffin for my 20B that I am very impressed with.  It is made to my dimensions and specs.  It is a very well built unit.  I've done the air-side flow test to verify their numbers and it looks good.  I'm not flying yet so have no operating data.

 

Photo attached.  Core dimensions 21.5 long; 5.3 high; 3.3 thick.  Designed for 2380 Btu/min.  Should be good for 200 hp continuous on a 95F day.

 

It is made to mount in the wing root in my Velocity.

 

Al Gietzen