I have to admit that besides cars I also have a passion for airplanes. It is no wonder I have started thinking about doing a radial engine (Wikipedia article). This configuration is used mostly on aircraft and it looks like this:
After some skunk work I have decided to implement one based on betula's design. The first prototype is ready and looks like this:
There are some differences though (besides the colors of course). For example in Betula's design none of the rods are fixed to the hub of the engine. To me this lead to some problems in practice. When changing the direction of the rotation it sometimes got stuck. In my design there is a master cylinder attached to the hub. It rotates very smoothly and does not have a tendency to get stuck. The other change is that instead of using a gear in building the crankshaft I use the normal half-pin shift part even though it means the engine got a bit longer.
And how does it look like while working? Like this:
Now if only I had time to build an airplane... (More images in the album.)