S&S CYCLE Evolution Big Twin Engine Case with 4.000" Bore - Part 31-0047

Engine Case - +4.000" Bore - Special Application - Evolution Big Twin

The S&S CYCLE 31-0047 engine case is engineered for high-performance Evolution Big Twin motorcycles, offering a custom fit for cylinder bores up to 4.000 inches. Crafted to accommodate larger stroke lengths of up to 5.000 inches, this case features a moved outward cam chest by 0.250 inches, providing enhanced clearance for performance builds. The design ensures optimal oil scavenging with a relocated cam chest oil pickup, which significantly reduces oil carry-over during sustained high-speed riding, promoting engine longevity and reliability. Built in the USA, this case is machined to accept the stock oil filter assembly used on '92-'99 Big Twins, ensuring compatibility with OEM components and ease of maintenance.

Features:

• High-performance design tailored for 4.000-inch bore and long strokes up to 5.000 inches

• Cam chest moved outward by 0.250 inches for increased clearance in performance applications

• Relocated cam chest oil pickup enhances gear case scavenging and minimizes oil carry-over at high speeds

• Machined to accept OEM oil filter assembly from '92-'99 Big Twins for seamless integration

• Ported breather passageway and machined breather window allow efficient air/oil mist flow from flywheel cavity to cam chest

• Two crankcase breathers recommended for engines larger than 95 cubic inches for optimal venting

• Deck height of 5.875 inches designed for durability and performance

• Machined to accommodate a crank position sensor, enabling EFI applications and easy installation of S&S IST Ignition and VFI Fuel Injection systems

• Includes a plug kit for engines not utilizing a crank position sensor

• Manufactured with a flat case mating surface and alignment dowels, ensuring proper fitment and alignment, with no case interlock groove or ring after June 1, 2008