|
John, I would go with the 22 1/4 sq inches. For
these reasons:
1. Your engine may produce more power than the one I
run with - requiring more heat rejection.
2. It is easier to neck down the opening (than widen
it) if it turns out you have more than what is necessary - or do
nothing
3. My cowl exit area is probably a bit larger than
most which may produce less back pressure enabling smaller opening to flow more
air.
Ball up your fist and see if you can stick it through the
narrowest opening - it should just almost go (that is if you have the same size
hands I do {:>)) How's that for a standard of measure?
Ed
----- Original Message -----
Sent: Thursday, March 01, 2007 9:39
AM
Subject: [FlyRotary] diffusers
Ed, If I add the extension, indicated with
cardboard w/lines, I have the original 22 1/4 sq. in's. If I block off
the cowl openings to match the diffuser, I will have 18 7/8 sq. inches.
The neck at the smallest point is approximately 15 sq. inches as close as I
can determine by my barn door math. Which is the better way to go,
opening wise, the larger or the smaller opening. If these numbers are in
the ball park, I'll lay up the glass. Thankyou JohnD
--
Homepage: http://www.flyrotary.com/
Archive and
UnSub:
http://mail.lancaironline.net/lists/flyrotary/
|