 Once the align bore is done and straight, we deck the block. Before we deck it would have to measure the deck height. We do this so we don't take too much off the block and so that we know the block is equal.
Deck height is measured from the main bore to the deck of the block. GM gets it close, but not close enough for us. The deck height from the factory on a small block Chevy is usually 9.025” to 9.033”. Our block has been taken down to 9.010”. |
The first thing we do is align hone the block. We need to cut the caps to about .001” to achieve a smaller bore. The more you take off the caps do more it will drop your main center to your cam center causing your timing chain to become looser. 
In this picture they are taking a chisel and dimpling the block just outside the cap so that the cap will be tight and always seat in the same place. It doesn't do much good to align hone the block if when you build it up the crank caps move. Each one is also numbered to put it together in the proper order later.
This is definitely an area where you'll want to have qualified machinists do the work. It may look easy but it can be tricky to get the job done right. 
All measurements are checked and rechecked. There is no room for error here!
The block is put in decking machine and leveled.