Cockpit air vent

Alan Cockrell · #1 10-06-2013, 12:48 PM

I recently bought an RV-6 from the widow of a deceased owner who was not the builder. I could not locate the builder for questions and the widow knew nothing, so what I saw is what I got.

The plane is in beautiful shape and I've been very pleased with it, but I have discovered a feature about it that seems to be an anomaly. The source for the cockpit air vents is not the usual side fuselage intakes but rather the top of the engine compartment over the no. 3 cylinder. I scratched my head trying to figure it out. The air there is clean and supposedly cool because it turns downward from there into the cylinder fins, but two things worry me. It would seem to rob cooling air, and an engine fire might get fed straight to the cockpit. The engine runs cool, so I'm not worried about that one. A fire should get forced to the bottom, but maybe it doesn't.

Anyway, I guess that all was done to improve drag, but I am very curious to know if any other RVs are built that way.

GLPalinkas · #2 10-06-2013, 01:04 PM

Alan, Your first post, I see. Welcome aboard VAF.

Yes, that is an air supply that I would move (for the reasons you cited). It should be easy enough for you to add a NACA vent in the standard location and duct it up to the vent feed.

131RB · #3 10-06-2013, 01:06 PM

Is it fuel injected or carb? This is the way I have done my cockpit cooling and it works great. If you have a carb the chances of fire on top of the engine are slim. If you are injected I would suggest some type of stainless firewall shutoff. AC spruce sells a 2 inch round stainless shutoff butterfly valve that you can clamp onto your firewall then hook your scat tube from the baffle to that.
Ryan

131RB · #4 10-06-2013, 01:24 PM

Spruce part # 08-07305
Ryan

java · #5 10-06-2013, 09:03 PM

Hi Alan. Welcome to VAF.

My purchased RV-6 has the exact same setup. It was built by an A&P in Colorado. I don't think I'd do it if I were building, but I'm not worried enough about it to change anything. Fire on top would be exceptional (I'm carburated), and cooling on that side is fine. Let us know if you do anything.

Alan Cockrell · #6 10-08-2013, 02:27 PM

Thanks gents. At least I'm not alone. My engine is carburated so I think I'll keep the set-up.