Ross's RV-10 Cooling Installation

Ross:

Would you mind posting some information on your RV-10 cooling system? You mentioned you had a radiator custom made by "Bell" I believe? How much did that cost, and how are you running the water to it and back? How are you attaching it to the fuselage? I am intrigued by it since I am using a Sam James "rotary" cowling on my 9A (with 13B) and don't have a bunch of room down below for the oil cooler and radiator without mounting both on angle. I would prefer to place both of them more perpendicular to the inlet airflow but don't want the airframe profile to look too fat either. Anyway, thanks for any information and I'll try and check your site from time to time for more pictures there.

Doug Lomheim
RV-9A, 13B
OK City ,OK

There are a number of pix here: http://www.sdsefi.com/air46.htm

The belly rad is very difficult to do nicely on RV3-9 due to the spar setup and lack of central tunnel like the -10. The -10 was no picnic either.

For the cowling and airframe you have, my advice is a single rad mounted under the oil pan fed by your shark mouth. If you can, build a dedicated duct which stays attached to the rad. This duct should diverge less than 7 degrees to the rad face if possible. If not, use guide vanes to turn the air without turbulence.

If possible, converge the exit duct aft of the rad and have a cockpit controllable cowl flap, this should reduce cooling drag measurably in cruise. This is harder to do well on an A model because of the gear junk in the way.

The rad shop of choice currently is http://www.macsradiator.com in Portland. Not afraid to do aircraft rads and had done a number for other aircraft. When I get back from Reno, I'll try to work out a size and fin/ tube spacing. Be aware that without a good duct design, tightly sealed to your inlet, required rad size varies considerably.

My view on flat mounted rads is that they have high drag although some people are using this setup successfully these days, I have not seen any comparative speeds.

Oil cooling is critical on the Wankel so consider cooler choice and ducting carefully.