The simple solution is to strap a generator to a piston engine, as BMW did with the two-cylinder range extender in its i3 EV. But if the engine never turns a wheel, there’s no need for it to rotate anything. Why not cut out the middleman and use the piston’s reciprocating motion to generate electricity? That obviates camshafts and most other rotating parts, too. The … Continue reading No crankshaft, Toyota’s free piston engine .