With the cold weather, it's been challenging to keep hands warm while working on the aircraft. In parallel, I've been attempting to tackle a critical issue as I prepare the aircraft for first flight: cold temp operations. My engine has a fifth bearing with very little clearance with the crankshaft. As a result, starting the engine when very cold could lead to damage. This is not only because cold oil won't reach the bearing, but also because the rate of thermal expansion between the crank shaft (steel) and the crank-case (aluminum) is sufficiently different that even with warm oil in the pan, the aluminum engine block may shrink down to 'trap' the crankshaft. Heating the engine before start is therefore critical to continuing first-flight preparations.
There are a lot of creative solutions on youtube, and I of course decided to draw from the most practical concepts. I purchased 1500 watt electric heater, and placed it inside a 6" to 8" round ducting coupler. This then feeds up to a short 6" duct which terminates in a modified floor register duct, angled to feed into the opening under the cowl. The heater is controlled with an InkBird ITC-306T, which has a temperature probe long enough to fit into the air inlet hole.
