S&S CYCLE - 31-0047 - Engine Case - +4.000” Bore - Special Application - Evolution Big Twin
Whether restoring a machine to factory spec or building something better, the S&S CYCLE 31-0047 gives you an engine case that meets the demands of serious street use. Designed for high performance engines with cylinder bores 4.000”. Cam chest is moved outward 0.250” to allow crankcases to handle large cylinder bore sizes, giving you a level of quality that holds up across the full service life of the component. Clearanced for strokes as long as 5.000”. 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 '92-'99 Big Twins. The 31-0047 is the kind of component that earns its place in any build or repair by doing exactly what it is supposed to, every time. Sold as a complete kit.
Features
- Designed for high performance engines with cylinder bores 4.000”
- Cam chest is moved outward 0.250” to allow crankcases to handle large cylinder bore sizes
- Clearanced for strokes as long as 5.000”
- 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 '92-'99 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; S&S recommends using both crankcase breathers in engines larger than 95”
- Deck height is 5.875”
- Made in the USA
- Machined for installation of a crank position sensor which allows the cases to be used in 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.
- All S&S crankcases manufactured after June 1, '08 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.
Specs
- Model: Special Application
- Units: Kit
- Color/Finish: Natural
- Product Name: Engine Case
- Riding Style: Street
Frequently Asked Questions - S&S CYCLE - 31-0047 - Engine Case - +4.000” Bore - Special Application - Evolution Big Twin
How do I know if this part fits my vehicle?
Check the fitment information listed on this page against your exact year, make, model, and (where applicable) trim, engine size, or configuration. If your exact vehicle isn't listed, or you're not sure, use the product chat on this page or contact our support team before ordering - we're glad to help confirm fitment.
What does it mean if a product is listed as universal fit?
Universal fit means the product is designed to work across a range of vehicles, not that it's guaranteed to fit every one. Compare the listed measurements, mounting requirements, and connector or hardware specs against your specific vehicle before ordering, since some installations may need additional hardware or minor fabrication.
Where can I find installation instructions for this product?
General installation notes are provided above where available. For detailed step-by-step instructions, refer to the manufacturer's documentation included with the product, or use the product chat on this page for questions about difficulty, required tools, or whether professional installation is recommended.
What if I have more questions about this product?
Use the product chat on this page for fitment, specs, installation, and compatibility questions, or contact our support team directly for help before you order.
