S&S Cycle 92-99 BT w/ 4-1/8in Bore Small Diameter Flywheel Special Application Crankcase

If you're building a high-performance Big Twin engine and need a crankcase that can handle larger cylinder bores, this S&S Cycle crankcase is a solid option. It's specifically made to accommodate engines with cylinder bores ranging from 4 inches all the way up to 4 3/8 inches, giving you plenty of room for custom builds. This crankcase is clearanced to work with strokes as long as 5 inches, so you can really dial in your engine's displacement.

S&S Cycle put some thought into how this crankcase breathes and handles oil. It features a ported breather passageway and a machined breather window to help oil mist flow from the flywheel cavity to the cam chest with less restriction. For engines over 95 cubic inches, they recommend using both crankcase breathers and cylinder head breathers for optimal venting. The cam chest oil pick-up has been moved outward by .250 inches, which helps with gear case scavenging and can reduce oil carry-over at high speeds. This design change also allows the crankcases to accommodate those larger cylinder bore sizes. It's also machined to accept the stock oil filter assembly found on 1992-'99 Big Twins.

This crankcase is designed to fit 1984-'99 Big Twins with 4-inch bore and larger, including S&S 4-inch bore engines like the V100, V107, and V113, as well as their 4 1/8-inch bore engines like the V124, V111, and V117. It also fits S&S 4 3/8-inch bore engines like the V126. Keep in mind that this part is not CARB approved and cannot be shipped to California.