Hello Steve, yes I have experience with using water spray.  In my configuration (Chubby Cubby, 80-90 mph climb) water spray would bring my maximum water temperature down by ~ 30 degrees F; typically would maintain ~ 180F in sustained climb.  Other info: it is very dependent upon heater core surface area - i.e., it worked well on a radiator core of 12" x 18" but had no measureable effect on an oil cooler that was 6" x 11.75"  ....  Jeff

Hi Guys

A successful 32 minute Flight #3. I was very pleased.

Main change this flight was winding in some prop pitch and extending the envelope to 140 KIAS.

Configuration of flight was:
OAT was a low 62F
Coolant Inlet - 21in2
Oil Inlet - 8in2
Total Outlet - 80in2
Coolant peeked at 226F
Oil peeked at 218F
EGT peeked at 1724F
Fuel Flow peaked at 18.7 GPH (Flowscan - not sure how accurate from the provided data)
We are still keeping immediately above the airfield

Reflections:
Idle RPM to low
Temps are to high on climb out but maybe OK when we get her up to her cruise of 190 KIAS
I will investigate water spray cooling for the initial climb. Does anyone have experience/data?

Here is a graph of the data.

Cheers

Steve Izett
Perth Western Australia