Great thing about also talking with the 20B racers in SoCal, is that these electric fans in front of the radiators work really well when they are staging, and draw a minimum of amperage for what they do.  Seems like that would work well in an aircraft stuck in line, or on a long taxi.  They come in a lot of different sizes and configurations.

Greg

Lancair in progress

Greg,

be a bit wary of the car racing guys. Not that they are not trying to help, I'm sure they are. The problem is that what works for a car set up wise is often completely wrong for a plane. How many of the racing guys that you meet down there take their car out firewall the throttle and leave it that way for an hour? Aircraft require a somewhat more conservative set up. You will need much better cooling than the car guys. They rarely run max HP more than about 20 seconds, That barely gets the water warm! if they have flow they could probably get by with 1 sqquare foot of radiator and a fish tank pump. You will need to run between 75% and 100%  in your plane most of the time! The rotary is well up to the task, but you need to concern yourself with a totally different operation pattern. Radiator wise the rule of thumb is a minimum of 2ci of radiator per HP for piston engines, Rotaries like closer to 3 cubic inches per HP. Not impossible but difficult to package.

 Be really careful about fans in your plane. At the higher air speeds we see a fan can become a real restriction. Also not many fans, (only the REALLY expensive ones), are designed to be freewheeling in a 200 MPH airstream! If you do run a fan I suggest that it cover only about 30% of your radiator so your high speed airflow will be OK. A lot of the guys are running a spray bar to put a little water on the rad in a idle on the ground. Kind of a patch but it works. You do of course have to provide a container and a pump as well. Better to do the rad right the first time.  

Bill Jepson