Have seen ball bearing pistons, rotary engines and induction, think they are neat so will use them.
Take one ball bearing and mount it in a circular tube so that is can roll freely. Add (reed) induction valves and carburetors at even intervals along the tube. Add compression and exhaust valves (at
the same intervals) to create inline cylinders arranged end to end around the tube.
Add an induction coil around the tube and create small cavity where a spark plug can be mounted directly before each compression valve.
To start the engine apply current to the coil, inducing motion in the ball bearing and drawing fresh charge into the tube through the carburetors after the ball bearing and providing compression (against the compression valves) before the ball bearing.
As the ball bearing reaches a compression valve the fresh charge is forced into the spark plug cavity where it is ignited. The compression valve opens allowing the ball bearing to continue its progress helped along by the expanding gases behind it.
The exhaust valves open and the spent charge is forced from the tube (and new charge is draw through the induction valves).
Once the engine is started draw current from the same coil used to start it...