Block Boring and Honing
We use a Rottler Boring bar[which has been precisely squared to the block mount so as to bore the cylinders square to the crank centerline] to rough bore the block to within .010-.015 of the finish size. By leaving this much meat left over to hone out, we are sure to completely hone out the microscopic rough jagged edges left behind by the boring bar cutter as it ripps through the cast iron. Most machinists only leave as little as .001-.005 to hone out. This is simply not enough meterial to hone to completely eliminate boring bar cuts. Many times we could still see the boring bar marks after another shop has final honed it. This is not good for ring seal or life! We use the Sunnen CV-616 cylinder hone to do the final hone and we finish with a Plateau hone brush to give an awesome cylinder finish. The Plateau hone wipes off the microscopic peaks of the cross hatch so the rings don't have to! We use only Genuine Sunnen stones and finish each cylinder with the appropriate grit stone for the ring being used. We do not do generic cylinder honing to a specific oversize, but instead measure every piston for consistency and give the appropriate clearance for the piston being used and the use it is intended for. Cylinder finish is critical for good ring seal and life! We also have a wide veriety of both aluminum and cast iron torque plates to use depending on the type of head being used. A torque plate is a thick plate with cylinder holes in it and it gets torqued to the block deck with the same type of head gasket that will be used. This torque plate pre-distorts the cylinder walls as to simulate a cylinder head torqued down. Then the block is final honed. This process insure a truely round, straight cylinder when the heads are bolted on and promotes much better ring seal right away. When a block is honed without a torque plate the ring must wear in to the out of round cylinder and may take as much as 10,000-15,000 miles for the rings to completely seal.