I finally came up with a design that I like for a carburetor heater solution. I'm just in the concept phase right now, but here is the basic idea.
1 - Carb setup I will kep the Zenith/Stromberg carb as it is, i.e. with a donut-shaped air filter clamped against the opening (the donut is held tight between two plates). 2 - Cold air intake I am going to build a kind of fiberglass box that will wrap around the air filter. The open side of the box will come in contact with the engine cowling wall. A NACA airscoop in the cowling wall will provide the inlet. 3 - Hot air intake I will make a hot air intake by adapting a flange to the engine baffles, in the cylinders cooling fins area. The air will be routed with SCAT tubing to the fiberglass box, then through the fiberglass box, to the middle of the outside air filter crush plate. This channel will be opened or closed using a butterfly valve that I will build from an aluminum flange. When you open the valve, in theory, both sources shoud work in parallel (cold air through the filter and hot air through the SCAT channel. But my bet is the hot air will win, because the SCAT channel will have less obstruction than the filter, and the engine cooling air is rammed by the propeller somewhat, plus expanding through heat. Anty thoughts on that? Serge Vidal KR2 "Kilimanjaro Cloud" Paris, France
