Service manual

2
Picture 1
Picture 1A
Introduction
S&S manufactures oil pumps in both cast and billet aluminum.
Cast oil pump kits are designed to replace stock H-D pumps
on all OHV Big Twin engines from 1936 to present except Twin
Cam 88. Cast pumps retain stock functions such as rear and
primary chain oiling. Billet pumps have no provision for rear
chain oiling.
All S&S oil pumps provide same oil volume and pressure as
stock 1973 and later H-D pumps with stock gears. Installing
any S&S oil pump on engine from 1936 to 1967 results in a
33% increase in supplied oil volume over stock cast iron pump.
An additional 25% increase can be achieved on engines from
1939 to 1972 if optional S&S pinion and oil pump drive shaft
drive gears are installed.
NOTE - Except for Knuckleheads, S&S recommends use of
optional pinion and oil pump drive shaft gears because
increased oil supply is usually beneficial. However, limited
rate of oil return from Knuckle top end will likely cause
problems if later drive gears are used. Even with standard
drive gears, Knuckleheads with S&S pump may require
restriction of top end oil supply. This is discussed in more
detail under notes on page 13.
IMPORTANT NOTES
● Chrome Plating - S&S does not recommend chrome plating
oil pump body or cover. Proper preparation for plating requires
abrasive buffing compounds. These materials can plug critical
passages and otherwise damage oil pump. Also, it is extremely
difficult to chrome plate an oil pump without altering critical
machined surfaces. Chrome in these areas or on gasket
surfaces can impair pump’s performance by altering operating
tolerances. In addition, chrome may flake and break loose
causing damage to pump and engine.
● Powder Coating - In our experience, subjecting heat-
treated alloys such as those used in S&S oil pumps,
crankcases, cylinder heads and other parts to excessive heat
can drastically alter their hardness, strength and other critical
properties. The degree to which these properties are altered
depends upon the temperatures reached and the duration
of exposure. When powder coating or otherwise processing
alloy parts, S&S exposes them to a maximum temperature
of 370 ° F for no longer than 20 minutes. Under no
circumstances should parts be heated past 400 ° F! S&S oil
pump bodies and covers are also chemically treated to insure
proper function. Excessive heat may alter treatment
compounds resulting in poor pump performance and
extensive engine damage due to insufficient lubrication.
#31-6006#31-6003
Picture 2
#31-6040 #31-6042 #31-6043
Billet Oil Pump Bodies
Picture 3
.080
.150
#31-6001
#31-6073
#31-6003