When I had my block sent to the machine shop, they zero decked it. What does this mean? Thanks.

 

The piston (excluding dome/dish) is at the same height (maximum stroke ie TDC) as the deck of the block (as measured from the crankshaft centerline).

Miles

 

The height of your cylinders of your block can vary, when it is zero decked the crank, rod, and piston are brought to top, measure the distance from top of piston to top of cylinder bore. If the piston is below block the block is machined to where the piston is the same height as the block. Use for getting prefered compression. calculate your head gasket thickness when torqued and your volume... cc's of your combustion chambers in heads and will give you your compression ratio. Had my heads milled to 81cc with .032 head gasket "squish" with zero decked block (coming) for 9.5:1 compression. (78 Pontiac 400 engine +.060).