Mazda B engine

The Mazda B-series engine - not to be confused with the Mazda B-Series truck - is a small-sized, iron-block, inline four-cylinder with belt-driven SOHC and DOHC valvetrain ranging in displacement from 1.1 to 1.8 litres. It was used from front-wheel drive economy applications to the turbocharged full-time 4WD 323 GTX and rear-wheel drive Miata as well as numerous other models. The Mazda B-series is a "non-interference" design, meaning that breakage of its timing belt does not result in damage to valves or pistons, because the opening of the valves, the depth of the combustion chamber and (in some variants) the shaping of the piston crown allow sufficient clearance for the open valves in any possible piston position.