Jeff,
Before you do all that modification, try a couple of flights using a
manometer to measure the pressure in front of the radiators, and behind the
radiators under the cowl. It might shed some light on where the problem
lies.
A manometer board is easy to make, just some tygon tubing on a support
board with some colored water in them. Take a flight and either take picture of
position, or write them down. Also, make only one change at a time so you know
what each effect is.
Bill
Sent: Friday, May 15, 2015 9:19 AM
Subject: [FlyRotary] Return to Flight - 2
Well,
the second flight occurred last night with same results as before; one short
low-level circuit due to insufficient cooling … looks like Al Wick made the
correct prediction.
There
are 3 things I can try with the current configuration: 1) Increase inlet area 2)
Increase outlet area (adjustable cowl flap) 3) Re-profile the pinched
diffuser. I will do all 3 and see what happens.
If
all of the above show remarkable improvement then repositioning the radiator is
the only alternative.
Jeff