S&S CYCLE Super Stock® 3.500" Engine Case for Big Twin - Part 31-0003

The S&S CYCLE Super Stock® 3.500" engine case (Part 31-0003) is a high-performance replacement designed specifically for Big Twin applications. Crafted in the USA, this precision-machined case is compatible with any stroke up to 5" and most stock-length connecting rods, making it a versatile choice for custom builds and engine upgrades. The case features a 3.5-inch bore and is machined to accept an oil filter assembly that mounts on the front of stock motor cases, ensuring compatibility with original equipment manufacturing (OEM) components.
All races within the case are line-honed to ensure optimal alignment and durability, while the breather cavity is precisely machined to enhance breather timing for maximum oil scavenging and efficient engine operation. The kit includes essential hardware such as crankcase bolts, washers, nuts, cylinder mounting studs, and a timing hole plug, simplifying installation and ensuring a secure fit. Additional components include a magnetic drain plug, assorted breather and oil line fittings, an oil pressure switch, oil screen, spring and plug, as well as a sprocket shaft Timken® bearing assembly and oil seal.
The pinion shaft main bearing race, cam needle bearing assembly, and oil pump drive shaft bushing are also included, providing a comprehensive upgrade for your engine's internal components. This case is machined for EFI fitment, supporting modern fuel injection systems for improved performance and efficiency. Designed for durability and precision, the S&S CYCLE Super Stock® engine case is ideal for enthusiasts seeking reliable performance and ease of installation in their Big Twin motorcycles.

Features:

• Machined to accept front-mounted oil filter assembly compatible with stock motor cases

• Line-honed races for optimal alignment and durability

• Precision-machined breather cavity for maximum oil scavenging

• Includes comprehensive hardware kit: bolts, washers, nuts, studs, and fittings

• Machined for EFI fitment to support modern fuel injection systems

• Made in the USA with high-quality craftsmanship

• Compatible with strokes up to 5" and most stock-length connecting rods