Certain engine blocks like the classic small block Chevrolet (and many other blocks) can require blind or semi-blind bores.

This is a problem in the honing process because the lack of clearance limits the lower over-stroke allowance. Lower over stroke is critical to getting a straight cylinder bore so removing material below these blind bores is critical.

Normally, clearing that material from the bottom of your bore is a slow, manual process. However, Rottler CNC boring machines including the F10, EM69, EM79 and EM100 series include a software feature for “X Offset Boring” which makes this process simple and accurate.

This programmable mode offsets the boring bar into the wall of the cylinder at the bottom of the bore (left or right side depending on where the obstruction is) and automatically clear the necessary amount of material below it. This delivers all the required clearance for honing properly post bore.

If you want to save a lot of time and effort and get the straightest and best finish after a blind bore, check out the video to see how it’s done!