Steve,

 

I am not the right person to try to answer your question.  Having retained the stock Van's cooling inlets for the coolant exchangers with essentially no diffusers, the result appears to be marginal cooling and high drag.  So I am asking myself the exact same question.

 

Steve Boese

RV6A, 1986 13B NA, RD1A, EC2

 

 

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From: Rotary motors in aircraft [flyrotary@lancaironline.net] on behalf of Stephen Izett [steveizett@me.com]
Sent: Tuesday, October 09, 2012 6:39 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: cooling airflow concepts

Thanks again Steve

My current snout looks similar to the attached image.

I'm considering going to the trouble of reworking the cowl into two circular duct openings, keeping them as far from the centre of the prop as possible.

Current opening is approx 7'' x 3'' - 21sqin.

Tracy I believe uses (Water Side) 5 1/4" so - 21sqin.

Multiply Tracy's by 2/3 (loose a rotor) + a bit for the extra side exhaust energy (Renesis) going into the coolant - say 15sqin's or 4 1/2 inch diameter.

The other attached photos are modified Glasair snouts

What do you think I should consider given the amount of work involved and the possible improvement factored in?

Cheers

Steve Izett