This is the most complicates engine I made up to now. I wanted to have an engine with working camshaft and valves and as I am a Volkswagen freak I designed it like a aircooled Beetle engine. At the end it was difficult to turn the crankshaft and I added a propeller. Now it´s a Volkswagen airplane engine.
Edit: I have been asked to upload the parts separated. Basically the parts have not been designed to be used separated but maybe someone can use them.