Hi Guys

I thought I should provide  an update.

Having installed 5 differential pressure transducers and interfaced them via spare Dynon EGT inputs, Ive been collecting some H2O diffuser pressure data.

First tests took pressure readings at 5 points (4 taps, 4 inches in from the four corners and one in the middle) referenced to the ships Static system.
Today I changed those taps to reference the pressure directly across the core at these same locations.

This has revealed the importance of measuring the pressure across the radiator as the pressures behind the radiator is not at all equal.

The data has revealed that our wedge diffuser was not equally distributing the air pressure across the radiator face very well at all.
Far more air was going through the back area as others have reported in the past.

So we will reshape the diffuser wall, making it harder for the air to get to the back and retest.

We have also increased the Oil inlet area from ~9in2 to ~ 14in2 and this has improved the oil temps.
On a flight today OAT of 79F on climb out Oil and H2O temps peaked at 210F.

I’m very happy with the changes and expect to get further improvements, and will shortly turn our attension to mechanising the cowl flaps to get temps up and cooling drag down in the cooler air.

Cheers

Steve Izett
Glasair Super IIRG Renesis 4 port RD1C, EC2, EM3