Summer brings high coolant temps - Model 4 Speedster, 912UL

[JackScott]

I have a Model 4 Speedster with an older 912UL engine. I?m seeing high CHT during full power climbs, with temperature going to 230 (top of the green arc) after a 1500 ft full power climb, and coming back down after 5-10 minutes at cruise power. CHT runs about 215-220 during normal cruise. Engine installation is factory stock, with the radiator mounted under the fuselage in a speedster scoop. Airplane is based in coastal Georgia, outside air temps have been in the 80s and 90s (and it?s barely summer).

The airplane starting flying last December after being down for about three years. I didn?t notice abnormal temps during the winter months, or before the airplane went down for maintenance. I?ve tried simple things, like flushing air out of the coolant system and blocking part of the scoop exit to force more air through the radiator, but nothing?s made a significant difference. Has anyone seen this before, and can you point me towards a fix?

Thanks for all your help,
Jack Scott

[atosrider]

the theory of air flow is the exit must be larger area than the inlet, creating a lower pressure zone and encouraging air flow ..

I wish I had the air scoop on my K3, just because they look cool rather than ugly stuff hanging out in the breeze.

regards