What is the recommended crankcase venting strategy for larger engines?

For engines larger than 95 cubic inches, S&S recommends using both crankcase breathers in conjunction with cylinder head venting. This helps manage crankcase pressure effectively in high-performance applications.

Can this crankcase be used with electronic fuel injection (EFI) systems?

Yes, this crankcase is machined to accept a crank position sensor, which is necessary for EFI applications. It also allows for easy installation of S&S IST Ignition and VFI Fuel Injection systems.

What is the maximum crankshaft stroke this crankcase can accommodate?

This crankcase is clearanced to handle crankshaft strokes as long as 5 inches, providing flexibility for various performance engine builds.

Specifications

Brand: S&S Cycle
Part #: 31-0047
UPC: 31-0047

S&S Cycle 92-99 BT w/ 4in Bore Special Application Crankcase - Natural

Name: S&S Cycle 92-99 BT w/ 4in Bore Special Application Crankcase - Natural
Brand: S&S Cycle
SKU: s-s-cycle-s-s-cycle-92-99-bt-w-4in-bore-special-application-crankcase-natural-t14-663812
Price: 2016.96 USD
Availability: BackOrder

$2016.96

On Backorder

Order now to reserve yours — we'll ship as soon as stock arrives. Full refund if we're unable to fulfill.

Key Features

Fits 1992-1999 Big Twin engines with cylinder bores between 4" and 4 3/8".
Ported breather passageway and machined breather window allow unrestricted air/oil mist flow to the cam chest.
Machined for crank position sensor installation, enabling EFI applications and S&S IST/VFI system compatibility.
Cam chest moved outward 0.250" to accommodate large cylinder bore sizes.
Clearanced for crankshaft strokes up to 5 inches.
Relocated cam chest oil pick-up enhances gear case scavenging and reduces oil carry-over at sustained high speeds.

This crankcase is designed for 1992-1999 Big Twin engines with specific cylinder bore sizes. Please verify your engine's specifications before purchase.

Secure CheckoutFast Shipping631-982-0042

About this part

Product Details

S&S Cycle is well-known for building robust engine components for performance motorcycles. This special application crankcase is designed for 1992-1999 Big Twin engines that have cylinder bores measuring between 4 inches and 4 3/8 inches. It's a solid foundation for a high-performance build, offering several updates over stock designs to improve airflow and oil management.

You'll find a ported breather passageway and a machined breather window that help move air and oil mist from the flywheel cavity to the cam chest with minimal restriction. This crankcase is also machined to accept a crank position sensor, making it ready for EFI applications and easy integration with S&S IST Ignition and VFI Fuel Injection systems. For engines larger than 95 cubic inches, S&S recommends using both crankcase breathers along with cylinder head venting to manage crankcase pressure effectively. The cam chest has been moved outward by 0.250 inches to accommodate larger cylinder bores, and it's clearanced for strokes up to 5 inches. Additionally, the relocated cam chest oil pick-up is designed to improve gear case scavenging and reduce oil carry-over at high speeds. It's machined to accept the stock oil filter assembly found on 1992-1999 Big Twins.

This crankcase is a substantial upgrade for builders looking to maximize performance and reliability in their Big Twin engine. It's built to handle the demands of larger displacement and higher RPM operation, with features aimed at improving oil control and engine breathing. Please note that this part is not CARB approved and cannot be shipped to California.