Crankcase, Assembly, 3-5/8" Bore, Alt/Gen, Packaged, 1948-'84 Custom Big Twin

Crankcase style Fitment: 

1.  1948 - 1999 Custom Chassis.  Check Clearances When Going above 93".

2.  1970 – ’99 stock chassis with alternator style primary.  ( FOOTNOTE #7 in second image chart )

3.  Electric Start Transmission Mainshaft:  1970 - 1985 Either Belt or Chain Drive.

4.  Engine Sprocket Shaft:  1970 & Later Crankshaft Assembly.

*For Further Clarification On Fitment Call For Detailed Explanation.

Manufacturer:  S&S Cycle
S&S Cycle Part Number:  31-0022

Used In Engine Assembly SH93 S&S Cycle Part #:  31-9917

Generalized Note #1:  All S&S crankcases use Timken® style sprocket shaft bearings and 1958 & later pinion bearings.
These cases will not accept stock 1957 & earlier flywheel assemblies.

Generalized Note #2:  Engines for 1936–’64 chassis with tin primary must use a 1955–’64 style inner primary cover.
Since all S&S generator style crankcases use 1958 and later style main bearings, stock flywheel assemblies 1957 and earlier cannot be used in S&S crankcases. Flywheel
assemblies must have 1958 and later pinion shaft with 1.250" diameter bearing, and a 1954 and later style sprocket shaft designed for a Timken® main bearing.
Generator style cases for 1936–’47 knucklehead engines are machined to supply oil to the heads from a boss located near the rear tappet guide or from a stock or S&S gearcover.
Provision for oil scavenging from the heads in these crankcases is the same as stock, with passageways that connect the tappet guides to the crankcase breather gear.
Crankcases for 1948–’69 engines are machined with a provision to separate the oil supply to the top and bottom ends if an S&S oil pump is used. This feature lets you choose the 1972
and earlier stock "side oiling" system or the 1973 and later split oil system. The stock cast iron oil pump can be used for the "original look" and stock oiling system. If an S&S billet oil
pump, part #31-6200 is used, the oiling system can be set-up as stock or updated to a split system.
1963–’65 panhead engines, with outside oil supply lines to the cylinder heads, must use the oil supply port located behind the rear tappet guide or the oil fitting toward the rear of the
S&S gearcover. S&S generator style crankcases do not have the stock style "outside oiler" oil supply boss, so special oil supply lines will need to be fabricated.