Line boring is the machining process that corrects the main line of the block . We at J and M utilize this process because it is much more accurate rather than line honing an engine mainline and saves the block and actually cost less since there is no need for shorter timing chains.

This is also part of the "Blueprinting Process". In these two photos we are line boring main line and camshaft bearings of this 1936 LaSalle 8 cylinder engine.

Line Boring Babbitt Bearings

After block or inserts have been poured the block is indicated and trued to the camshaft and centerline of block the block is line bored to accept the reground crankshaft and also machine the thrust of the bearing surfaces

1936 LaSalle main line.

Line Boring babbitt bearings you can see the
mirror finish.

Line boring main line and camshaft bearings of this
1936 LaSalle 8 cylinder engine.