[ted]

I haven't seen any specific guide lines regarding minimum cylinder wall thickness and that's probably because of different block constructions and the different materials being used.

I try to maintain at least .090" for the minimum thickness and the more the better. There is the major thrust side in the cylinders that takes the most abuse and subsequently these should be left thicker than the opposite or minor thrust side. The Major thrust sides would be the outside of the cylinders on the passenger bank and the intake valley sides of the cylinders on the driver's bank.

Where you run into a problem is when the major thrusts in the block are already thinner than the minor thrust sides. This is where sonic checking really proves it's worth as you can weed through the less desirable blocks.

Ted Eaton.