1.8L 16v - BO 

The MAZDA 1.8L 16v BO block is covered here by a single item, and it is the centrepiece of any build: the WOSSNER kit of four forged pistons. Two sizes are offered, an 83.5mm bore for a first rebore and an 84mm bore for a second, both with an 8.6:1 compression ratio. That moderate ratio suits an engine destined for boost or for sustained hard use, where the cast original part reaches its limit. Forging brings the mechanical strength needed for high engine speeds and heavy thermal loads.