Perfect for stock replacement and high performance applications, these crankcases offer some unique features. Besides being machined for a crank position sensor, they are also compatible with stock flywheel assemblies, primary covers, gearcovers and are clearanced for 38 amp alternator stators.
Features and Benefits:
- Relocated cam chest oil pick-up increases gear case scavenging and virtually eliminates oil carry-over at sustained high speeds
- Machined to accept the stock oil filter assembly used on 1984–'91 big twins
- A ported breather passageway and a machined breather window allows the air/oil mist to flow from the flywheel cavity to the cam chest of the engine with the least possible restriction
- Crankcase venting can be achieved via two crankcase breathers, the cylinder heads, or both. We recommend using both crankcase breathers in engines larger than 95"
- Clearanced for strokes as long as 5"
- Compatible with stock 1984-'99 flywheel assemblies, primary covers, gearcovers, and clearanced for 38 amp alternator stators, making them perfect for stock replacement or high performance applications
- Machined for installation of a crank position sensor. This allows the cases to be used in stock EFI applications and also allows easy installation of S&S IST® Ignition and VFI Fuel Injection. A plug kit is included for applications that do not use a crank position sensor
- Available for stock, 3 5/8", and 3 13/16" bore applications with deck heights as much as 3/16" taller than stock
- Natural aluminum and wrinkle black powdercoat available
|Crankcase Style||Finish||3 1/2" Bore (Stock)||3 5/8" Bore||3 5/8" Bore (Small Diameter)||3 13/16" Bore||Notes|
|1984–'91||Natural||31-0000*||31-0001||31-0072||31-0031||2, 3, 4|
|NOTES: 1. 1992-'99 style oil pump. 2. 1984-'91 style oil pump. 3. Machined for 1984-'99 alloy primary. 4. Machined for stock or S&S EFI crank position sensor. Stock diameter only.|
*S&S Crankcase 31-0000 directly replaces Harley-Davidson® part number 24469-83A. **S&S Crankcase 31-0052 directly replaces Harley-Davidson part number 34473-85A.Note: All S&S crankcases manufactured after June 1, 2008 do not have case interlock groove and ring and do not use case alignment studs. Case mating surface is flat, and cases are aligned with alignment dowels. All reference to H-D® part numbers is for identification purposes only. We in no way are implying that any of S&S Cycle's products are original equipment parts or that they are equivalent to the corresponding H-D® part number shown.