Abstract: A surfacing and boring machine for reconditioning engine blocks has a front stationary work table, a traveling column on rails provided by an elongated rigid base, a power head unit on the column adjustable in an air float condition to move an overhanging spindle forwardly and rearwardly, and mechanisms in the power head unit to independently move a spindle carrier vertically and to rotate the spindle at selected speeds. Clamping devides are provided to independently clamp the power head unit to the traveling column and the column to the base rails. A quick-change unit is located in the spindle for the tools.

Abstract: An engine block reboring system for main bearings in which the block is mounted on a pair of rails extending laterally on a workbed and is rebored by a tool driven by a right-angle drive extension on a vertical boring machine after the position of the block has been adjusted so that the vertical axis of the boring machine spindle and the desired reboring axis are in the same vertical plane, and the proper height for the tool is set for reference, so that the bearings can be rebored by manipulating the spindle vertically and horizontally in said vertical plane with respect to the height reference. Apparatus is provided for initially properly aligning the block and keeping it in aligned position during the reboring operation.

Abstract: A honing machine includes a specially designed, pneumatic short-stroking circuit which may be actuated to oscillate a honing tool in the bottom of a bore to remove lower bore tapers with increased speed and efficiency.

Abstract: An improved sled for fixturing engine blocks includes an inclined mounting surface which can be supported at alternate inclinations for fixturing engine blocks having various V-angles. A preferred embodiment utilizes a two-way frame which is removably mounted on the sled for supporting various V-blocks with the main bearing cap in place. Air float means are also preferably provided for lifting the sled above a supporting surface to facilitate maneuvering the sled. One preferred embodiment includes a novel means of aligning and securing an engine block on the sleds which includes a sling for rotatably engaging and lifting a block.

Abstract: A "beam stroker" type of honing machine which can, at the operator's option, be power stroked by means of a double-acting pneumatic cylinder or manually stroked. Both travel limits can be varied by the operator. A hydraulic double-acting cylinder system functions to limit the stroking speed and has a needle valve adjustment to vary the speed.