As if opposing piston designs weren’t already different enough, the Napier Deltic engine takes it a step further. Moving to a three-crank configuration. As the “Deltic” name alludes to, the cylinders are arranged in the form of a triangle, with each cylinder making up each side, and crankshafts at the triangle’s vertices. Three triangular sections were combined to make for an 18-cylinder engine with 36 pistons. By staggering firing events across the banks of cylinders, the engine was particularl