[Andyman]

The timing of power strokes in a four cylinder engine converted to run on two cylinders would be the same as a normal two cylinder engine, assuming both are four stroke engines. It wouldn't make sense to turn off two cylinders that fire consecutively. That would be very shaky.

A two cylinder engine does require a higher speed than a four cylinder engine to be as smooth. In my experiment, the idle was pretty good at about 1100 RPM in neutral. When driving, I had to keep it over 2000 RPM for reasonable smoothness. When the torque converter locked up I needed to keep it over 2400 RPM to run smoothly. It was more practical on the highway than in local driving.

A flexible rubber coupling (called a guibo or flex disk) on the driveshaft or axle shafts would be helpful to reduce the shaking. Mercedes and BMW often use this at the front of the driveshaft.