The Sunnen CV-616 is the cylinder hone we use to finish our blocks.
If we rough bore a block with the boring bar, we always leave at least
.010"-.015" to hone out. This insures that all the microscopic rough
edges left by the boring bar are completely honed out so a proper
finish can be attained. We use the appropriate Sunnen stones to finish
the cylinders to the desired finish for the rings being used. Once a final
size is acheived, the block is left to cool. After cooling, the cylinders are
touched up as some shrikage will occur. After final finishing is done, we
run a plateau hone through each cylinder to round off the peaks left behind
by the stones that the rings would normally wear off into your oil. This
creates a superb sealing surface for the rings to seat into.
To acheive proper piston to cylinder wall clearance, we measure each
piston for consistency and add the proper clearance to that. After the dial
bore gauge[Sunnen, reading in increments of .0001] is set, it is double checked
with the micrometer used to measure the pistons. This insures accuracy.
We have deck Torque plates for most popular engines. Torque plates are
thick plates[aluminum for aluminum heads and cast iron for iron heads]
with cylinder holes in them that can be torqued down with the head gasket
type that will be used in final assembly. This "predistorts" the cylinders so
when the cylinders are honed, they will be honed as if the head was torqued on.
This creates immediate ring seal and does not require thousands of miles to
"wear in" the rings to acheive this seal.
Torque plates are a must for race engines since they don't have thousands
of miles to spare to acheive ring seal.