1941-1947 Knucklehead Left Engine Case Unmachined

Knucklehead left hand engine case features steel bearing insert cast in and is machined to fit OE right side case. Machined steel insert case in place. Case is not a bolt in installation.
Serial number pad for 1936-47 is 5/16" wide and 2-1/4" long, and the 1936-42 pads feature a line between the pad and the case. Case is not a bolt on part, features a steel bearing insert cast in. Macined to fit OE right side case. Order cylinder base studs, case race, timing plug and drain plug separately. Features blank number boss for serial number. Case set required line lapping of the main case races. Order case race available separately. Left side cases accept standard case race. **NOTE: Cylinder deck height and motor mount surface must be fit and machined to match the right side case. **NOTE: Short rib case used 1936 - mid 1941. Last 1941 production thru 1947 have the high rib, for the added strength needed for 74 cubic inch. **NOTE: Case requires machining before installation. Check the inside diameter before machining for Flywheel fit. **NOTE: Areas will have to be machined separately.