I have talked to quite a few people who are flying or have
built the planes with the 912 and many have even left off the water
radiator and went with an oil cooler only installation.

Gary,

Your mention of no coolant radiator is a bit surprising as the coolant
heat rejection is 2-4 times that of the oil on a Rotax 912 or 912.
There are hundreds of Rotax 91x powered aircraft around here and it is
the first time I hear of dispensing with a coolant radiator..
Could you be more specific as to what type of aircraft, etc ?

Thanks,
Regards,

Gilles Thesee
Grenoble, France
Rotax 914 MCR 4S with cowl flaps