Some people claim that it is not possible to bore a Corvair cylinder to this oversize.  This may be correct,   given the way most shops will bore Corvair cylinders.  Our custom built torque plate fixture not only assures 0.020" to 0.060" Corvair cylinders will be round and true but it also allows us to bore these cylinders to 0.125" over.

These .125 over bore Corvair cylinders are specifically intended to be used in racing engines where as there is a restriction in the class stating only Corvair cylinders can be used.  At this large of an over bore the cylinder walls become very thin and long term ring seal may be an issue.    Because of this we do not suggest that these large cylinders be installed in a general use engine or one that is built for long term reliability.