Sleeve Bore Engine Blocks - Sleeve It Save It

The boring operation is done in several steps, until the final cut is made to a precise size.

The block isn't bored all the way through, but a step is left at the bottom of the bore to serve as a register, positively locating the sleeve.

To ease the installation, the liner is chilled in a special apparatus with CO2 gas, causing it to contract.

Installation of the sleeve is done with a driving fixture and a big mallet. The sleeve is driven in until it is solidly against the register that was left at the bottom of the cylinder during the boring process.

Next, the block returns to the boring bar to have the sleeve cut down to within a few thousands of the deck surface in preparation for surfacing. After the deck is surfaced, the cylinder is bored to size. in this case, it's bored in preparation of a final honing to the original .040-inch overbore dimension.

Our block was carefully measured and shimmed in the surfacing machine so the surface cut to the block could be held to a minimum, and then machined to bring the top of the new liner dead even with the block surface.

The new hole looked as good as new.

The last operation is to finish hone the bores. The sleeved cylinder needs to be honed to size, but the adjacent cylinders also need honing to correct for distortion caused by the sleeve's press fit. We had Dave torque plate hone all of the holes while the block was in the machine.