Four spark plugs, eight pistons, one stroke: How the INNengine E-REX promises to be different

The INNengine e-Rex is tiny and can change compression ratios in the blink of an eye. But that's just the start of what makes ...
CNET

Pinnacle engine: Two pistons, one explosion

Over the roar from a 110-cc, two-cylinder engine, Pinnacle Engines founder James Cleeves (nicknamed Monty), pointed out a window in the block. “You can see the cylinder sleeve moving for the intake ...