Engine #1

    When building anything new there's always unexpected bugs that need worked out & the experimental engine #1 was no exception. As simple as it looked on paper, it was a struggle to work through the problems it had. The engine was designed like a normal 3-port, 2-stroke but the fuel feed is a little different than most.

    If you're familiar with 2-stroke engines, usually the air-gas mixture is brought in through a carburetor & mixed before entering the crankcase. This engine is like a 3-port, 2-stroke in that the intake port is uncovered below the piston when at TDC, but there's an "air only" port & across from it, another smaller port just for the fuel. When the piston starts moving to BDC both ports are covered (& supposedly sealed by the piston). The goal of this was to get rid of the little trouble-making check valve that keeps the fuel from flowing back into the tank when it isn't being drawn into the engine. On a lot of engines, especially the smaller ones, if this check valve sticks or isn't seating properly, the fuel level will vary & cause the engine run erratic. The extra fuel port on engine #1 looked simple enough on the drawings but when put into practice, found there were some tricks to getting it to work right.

    Engine #1 also suffered from ignition problems. The goal was to use simple points that looked good & worked good with the engine; a lot of time was spent on the "work good" part. There was also some time spent on piston design. Instead of using a normal cylinder by-pass, the final piston used in the engine has a featherweight disc valve in the top of it. At first, different ball valve pistons were tried for their ease of machining but balls have a small surface to weight ratio; the engine ran but had problems.

A video of the engine running with the disc valve piston is at;