Hello All:
Up until this past weekend I have purposefully avoided using a thermostat in my 13B aircraft engine - reason being is that many years ago I had one stick open and another stick closed in my GMC truck.  Encouraged by reading Steve Boese's flight report from last fall, I decided to give one a try.  Operation up here in the frozen north requires some method of maintaining engine temperature when power is reduced or when it's really cold.  Cowl flaps, louvers and mechanical controls are okay but they add a lot of weight and complication VS a simple thermostat.

I opened up the top of my water pump housing, extracted the bypass plug, removed my 0.75" restrictor plate and inserted a 180F thermostat from Racing Beat.  On Saturday I refilled the coolant system, pressurized it and ran the engine up to temperature.  On Sunday I bled off the remaining pressure, rechecked the system, pressurized it to 8 PSI and went flying.  At first I felt a bit uneasy as the engine warmed up to 185F-indicated while still on the ground - but I assured myself that is what it's supposed to do !  Other than my gauge reading 185F and the device being advertised as 180F it worked flawlessly; temperature never varied at all and there was a good source of cabin heat.  OAT was about 3C or 36F at the time.

My plan is to leave the thermostat in place for now and keep a close watch on engine temps as the OAT rises next spring/summer.  I expect it will be removed for summer operations and re-installed again around October 2018 ... we'll see.

Jeff
13B, RD1C, 130 hrs TT.