Tracy,
I really believe you will be better off with the round cowl inlets. What oil cooler are you using there? Powersport never had good cooling from that lower inlet. They used the firewall mounted radiator with rather poor ducting. I believe you would have to bottom mount the radiator and carefully duct it for the lower scoop cooler to work, and then only with an increase in cooling drag.
Bill Jepson
PS. What are the dims. on your radiator again? WRJ
-----Original Message-----
From: Tracy Crook <lors01@msn.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Wed, 1 Feb 2006 12:23:12 -0500
Subject: [FlyRotary] Re: Cooling air inlets
Not that the purpose built cowl will not work but I felt that fitting and optimizing all the systems was more straight forward and easier with the 'classic' cowl. Not shown in the picture is the intake manifold which is similar to the one in my RV-4. It would stick out the side of the purpose built cowl. This is just one of many factors. Also, I think Will James who makes the purpose built cowl was still working out the rights to market it (it was originally for Powersport) when I got mine.
Tracy
----- Original Message -----
Sent: Tuesday, January 31, 2006 4:59 PM
Subject: [FlyRotary] Re: Cooling air inlets
Tracy, just wondering why you went for the "classic" cowl instead of the Sam James purpose built rotary cowl?
Greg
Hi John,
There are no ballpark figures, only arguments about them : )
FWIW, I am using a Sam James cowl with 5" round inlets and fervently hope that they will cool my 20B.
Tracy (dangerously close to first engine start)
----- Original Message -----
Sent: Sunday, January 29, 2006 8:06 PM
Subject: [FlyRotary] Cooling air inlets
I am modifying the cowling for the Tailwind. The air inlet holes are 2 5/8"s x 7.5"s for a total of app. 21.5 sq. inches. x 2 for a total of 43. I am looking at a 5 inch round hole which is the size that Same James is using for the O-320's, which would make the diffusers easier to fabricate. The round 5 " hole has approximately 19.3 sq inches x 2 for 38.6 sq. inches total, if my math is right. Is this a ball park figure for the water coolers (GM evaporators) on the Mazda 13 B engine. JohnD
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