What does boring a motor out 30 over mean?
It may mean the cylinder walls are damaged, such that they need to be bored 0.030″ (“thirty thousandths”) larger than the OEM specs. (If that’s the case, you may not be able to have the cylinder bored again, so try to avoid the circumstances that led to this, such as running the engine excessively hot, or overstraining it.) (Or, it might be someone’s idea to increase the displacement, thus increasing the torque produced by the engine. As a performance upgrade, this would be about the last thing I would do, as there are cheaper means of getting more power, such as a less-restrictive exhaust system. Also, keep in mind it would void any existing factory engine warranty.) This does require an “oversize” piston; replacement pistons are available in the correct size, just specify the 0.030″ oversize.
