S&S Worldwide S&S Twin Cam Style Engine user manual

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Instruction Sheet #51-1160

04-28-04

Copyright®, 2003

by S&S Cycle, Inc.

All rights reserved. Printed in the U.S.A.

Because every industry has a leader

S&S Twin Cam Style Engine

Assembly and Installation Instructions

S&S Cycle, Inc.

14025 County Highway G Box 215

Viola, Wisconsin 54664

Phone: [phone] • Fax: [phone]

Technical Service Phone: 608-627-TECH (8324)

Technical Service Email: [e-mail]

Website: www.sscycle.com

For all S&S Twin Cam style Engine Assemblies with Twin Cam style or

optional Evolution style engine mounting.

All S&S Twin Cam style Engine Assemblies are

Type "A" style (non-counterbalanced).

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SAFE INSTALLATION AND OPERATION RULES:

Before installing any S&S engine part, it is your responsibility
to read and follow all instructions. The rules below are for
your personal safety, and must be kept in mind at all times.

● Gasoline is extremely flammable and explosive under
certain conditions, and toxic when inhaled. Do not smoke
around gasoline. Perform the installation in a well-ventilated
area away from sparks or open flame.

● After installation, be sure all fuel lines are routed correctly
with clamps in place and tightened securely. Even with
protective cover, gas lines must not contact extremely hot
surfaces where they could melt or leak and catch fire.

● Compressed air and particles dislodged by
compressed air are potentially harmful. Wear protective
goggles when using compressed air and always direct
the air stream away from yourself and others nearby.

● Some solvents, degreasers and other chemicals are
harmful, especially to skin and eyes. Many chemical
compounds such as lacquer thinner are also flammable and
present a fire hazard. Read the manufacturer’s instruction
label for precautions and proper use. Use in a well ventilated
area and wear protective clothing to avoid personal injury.

● If the motorcycle has been running, wait until the engine
and exhaust pipes have cooled before performing any
mechanical work.

● Before beginning the installation, disconnect and remove
the battery to eliminate potential sparks and possible
inadvertent engagement of the electric starter while working
on the motorcycle.

● Read instructions thoroughly and carefully so all
procedures are completely understood before beginning
installation. Contact S&S if you have questions, if any steps
are unclear, or if any abnormalities occur during final
assembly, installation, or operation.

● Consult an authorized H-D service manual for correct
disassembly , reassembly, and installation procedures for any
parts that need to be removed or disassembled to facilitate
the installation.

● Use good judgment during assembly, installation, and
when operating the motorcycle. Good judgment begins with
a clear head. Don’t let alcohol, drugs, or fatigue impair
judgment. Perform installation when fresh and alert.

● For optimum performance and safety and to minimize
potential damage to the cylinder heads or other components,
use correct hardware and follow procedures outlined in S&S
instructions and authorized H-D service manual.

● Motorcycle exhaust fumes are toxic and must not be
inhaled. Run motorcycle only in a well ventilated area where
fumes can dissipate.

WARRANTY :

All S&S parts are guaranteed to the original purchaser to be
free of manufacturing defects in materials and workmanship
for a period of twelve (12) months from the date of purchase.
Merchandise that fails to conform to these conditions will be
repaired or replaced at S&S’s option if the parts are returned
to S&S by the purchaser within the 12 month warranty period
or within 10 days thereafter.

In the event warranty service is required, the original
purchaser must notify S&S of the problem immediately.
Some problems can be rectified by a telephone call and need
no further action. Apart that is suspected of being defective
must not be replaced without prior authorization from S&S. If
it is deemed necessary for S&S to make an evaluation to
determine whether the part was defective, it must be
packaged properly to avoid further damage, and be returned
prepaid to S&S with a copy of the original invoice of purchase
and a detailed letter outlining the nature of the problem, how
the part was used, and the circumstances at the time of
failure. If after an evaluation was made by S&S and the part
was found to be defective, repair, replacement, or refund will
be granted.

ADDITIONAL W ARRANTY PROVISIONS:

(1) No part shall be returned to S&S without first contacting
the company and obtaining a Return Authorization (RA)
number.

(2) S&S shall have no obligation in the event an S&S part is
modified by any other person or organization, or if another
manufacturer’s part is substituted for one provided by S&S.

(3) S&S shall have no obligation if an S&S part becomes
defective in whole or in part as a result of improper
installation, improper break-in or maintenance, improper use,
abnormal operation, or any other misuse or mistreatment.

(4) S&S shall not be liable for any consequential or incidental
damages resulting from the failure of an S&S part, the breech
of any warranties, the failure to deliver, delay in delivery,
delivery in non-conforming condition, or for any other breach
of contract or duty between S&S and a customer.

(5) S&S parts are designed exclusively for use on
motorcycles with Harley-Davidson style V-twin engines. S&S
shall have no warranty or liability obligation if an S&S part is
used in any other application.

IMPORTANT NOTICE:

Statements in this instruction sheet preceded by the
following words are of special significance:

WARNING
Means there is the possibility of injury to yourself or
others.

CAUTION
Means there is the possibility of damage to the
motorcycle or a component.

NOTE
Other information of particular importance has been
placed in italic type.

S&S urges you to take special notice of these advisories.

S&S Basic Twin Cam Style Engines for Evolution Style Chassis *

Displacement Bore Stroke Fuel System Finish

Assembled

Part Number

Natural 31-9340

124" 41⁄8"45⁄8" Carburetor

1

Black 31-9341

Natural 31-9343

124" 41⁄8"45⁄8" S&S VFI

2

Black 31-9344

S&S Basic Twin Cam Style Engines for Twin Cam Style Chassis*

Displacement Bore Stroke Fuel System Finish

Assembled

Part Number

Natural 31-9330

124" 41⁄8"45⁄8" Carburetor

1

Black 31-9331

Natural 31-9333

124" 41⁄8"45⁄8" S&S VFI

2

Black 31-9334

* For installation in Stock Harley-Davidson Twin Cam Chassis only. Balanced version unavailable.
1 Carbureted engines include an S&S IST ignition system and an S&S Super G or D carb.
2 Fuel injected Engines include S&S Variable Fuel Injection (VFI) system with your choice of S&S tuned or teardrop induction, and either

Magnetti-Marelli or Delphi style S&S VFI Module

A. Introduction

S&S 124 Twin Cam Engines are available in two
versions The first version is designed and intended for
installation in a stock Harley-Davidson Twin Cam
Chassis. It will bolt directly to the stock transmission
and engine mounts of chassis designed for stock
unbalanced Twin Cam engines. The second version of
Twin Cam style Engine is machined with an Evolution
style rear motor mount. It may be installed in a stock or
aftermarket Evolution style chassis. Both versions are
available in natural aluminum or black powder coat
finish.

S&S 124" T win Cam style Engines are available only in
a Basic version, meaning that some stock Harley­Davidson or aftermarket Twin Cam style parts will be
needed to complete the engine. The extra parts
needed include: oil pump, oil pressure switch, cam
support plate, cam cover, tappets, tappet covers, and
oil filter bracket.

Installation can be performed by any Harley-Davidson
repair shop equipped to do complete engine overhauls.
No special tools other than those used in normal
engine building operations are required.

NOTES

●

Installation of a fuel injected engine in a motorcycle that
was originally equipped with a carburetor is fairly difficult
and expensive. This conversion requires a fuel pump
equipped gas tank as well as wiring harness.

●

All S&S Twin Cam Style engine assemblies are for Twin
Cam “A” (non-counterbalanced) engine applications, and
are not for use in Twin Cam “B” (counterbalanced)
applications.

●

A balanced Twin Cam style Engine is not available from
S&S Cycle at this time.

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* For installation in Stock Harley-Davidson Twin Cam Chassis only. Balanced version unavailable.
1 Carbureted Long Blocks include an S&S IST ignition system and an S&S Super G or D carb.
2 Fuel injected Long Blocks include S&S Variable Fuel Injection (VFI) system with your choice of S&S tuned or teardrop induction, and either

Magnetti-Marelli or Delphi style S&S VFI Module

I.Oil Tank, Fittings and Oil LIne
J. Exhaust System
K. Initial Start-up and Engine Break-In
L.Tuning Guidelines
M. Engine Specs and Torque Values
N. Service Intervals
O. Replacement Parts

Instruction Contents:

A. Introduction
B. Additional Features
C. Modification Notes
D. Engine to Frame Test Fit
E. Engine Assembly
F. Engine to Frame Assembly
G. Ignition System
H. Fuel System

Please read these instructions carefully before starting work. Proceed with the installation only after the instructions
are completely understood. These instructions should be supplemented by the appropriate OEM service manual for
your motorcycle. Follow all safety information.

B. Additional Features:

● Greater overall strength than stock crankcases,
especially in the front motor mount, an important
consideration in high performance applications.

● All oil passages between the crankcase and cam
support plate are o-ring sealed.

● Compatible with stock components. Use stock oil
pump, cam support plate, gear cover, etc.

● Uses 1999-2002 Timken style sprocket shaft bearing.

● Uses 2003-up pinion shaft bearing

S&S Twin Cam Style Engine Instructions often
refer to procedures described in other S&S
instructions or a Harley-Davidson Service Manual.
These materials should be cross-referenced as
necessary.

IMPORTANT
Before proceeding, verify that serial numbers on
crankcases match numbers on packing carton and
certificate of origin. Contact S&S immediately if
numbers do not match.

NOTE - Valid certificate of origin is required for any transfer
or sale of longblock assemblies. Certificate of origin is
required to title and license any motorcycle which is to be
driven on public streets and highways.

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Dynomometer chart showing typical horsepower and torque curves for S&S 124” Twin Cam style engine.
Horsepower and torque curves will vary, dependant on the engines state of tune, and the ignition and fuel

systems used on the completed engine.

Torque

Horsepower

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C. Modification Notes

S&S Cycle cautions against modifying these
crankcases due to the possibility of damaging or
weakening them. Modifying S&S crankcases in any
fashion voids all manufacturer warranties. Should the
customer elect to modify the crankcases regardless, it
is imperative that they and the information tag attached
to them be inspected beforehand to confirm that the
correct model, style, bore size, etc. have been
provided. The customer must confirm that crankcases
and related parts are correct before assembling them
or having them modified in any manner, and assumes
all liability for modifications.

Under no circumstance will S&S be held responsible
for expenses related to the modification of any S&S
part in the event warranty service is required. Modified
parts will not be accepted for credit or exchange. This
will apply regardless of cause or fault: customer,
retailer, manufacturer, or other.

For further information, contact S&S Technical Services
at 608-627-8324, FAX [phone] or e-mail
[e-mail]

NOTE - “Modification” includes but is not limited to
appearance changes such as painting, powdercoating,
plating, and polishing. Proper preparation for these
procedures as well as the processes themselves may
require the use of polishing compounds, chemicals or
procedures that are potentially harmful to crankcases.

CAUTION - Passages and internal cavities may become
obstructed by residues from materials used to polish,
paint, plate or powdercoat surfaces. Additionally,
surface finishing processes can damage critical
machined surfaces. Any of the above may cause
premature wear, damage or failure of other engine
components as well as the crankcases themselves.
Glass bead and polishing residues are abrasive and
can be difficult to remove from recesses and small
passages. Abrasive residues can cause oil
contamination and extensive engine damage. Engine
damage caused by powder coating, polishing, glass
bead blasting, or other modification will not be covered
under warranty.

Powder Coating - Subjecting heat-treated alloys such

as those used in S&S crankcases to excessive heat
can drastically alter their strength and their critical
properties. The degree of change 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 strongly recommends trial-fitting every engine
before frame is painted or powder coated.

D. Engine to Frame Test Fit

NOTE - The engine must be fitted to the frame it is installed
into. It must rest squarely on its attachment points, and
bolted solidly to the frame without stressing the engine
case at any point. If possible, crankcase should be
positioned in motorcycle frame before assembly to check
alignment and clearances. The same clearancing and
alignment steps must be taken for assembled engines.
Performing the clearance alignment checks with a bare
case is convenient due to the reduced weight.

CAUTION - Failure to correctly mount the engine can
cause problems not covered under warranty including
but not limited to, excessive vibration, driveline mis­alignment, and broken castings.

CAUTION - Do not carry crankcase by the studs. It
stresses the crankcase and studs in ways they are not
designed to handle. Also, it is easy to drop and damage
the case when it is carried by the studs.

1. Test-fit instructions for Twin Cam style cases
with stock Twin Cam style engine mounts.

1. Assemble case halves using case bolts.

Tighten to snug. Torquing bolts to final
specification is not necessary.

2. Clean frame engine mounts and carefully

remove any irregularities from mounting
surfaces. Also inspect crankcase mounting
bosses for burrs.

3. Position case in frame, check for clearance at

frame, and alignment to transmission. It is a
good idea to replace rubber engine mounts at
this time. Old mounts deform over time and
can induce unwanted stresses on the engine
case.

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CAUTION - Improper alignment of engine and frame
mounts may cause abnormal stresses resulting in
damage to crankcases or other parts.

2. Test-fit instructions for Twin Cam style cases
with Evo Style motor mounts.

1. Assemble case halves using case bolts.

Tighten to snug. Torquing bolts to final
specification is not necessary.

2. Clean frame engine mounts and carefully

remove any irregularities from mounting
surfaces. Also inspect crankcase mounting
bosses for burrs.

3. Position case assembly in frame.

4. Install engine mounting bolts in motor mounts,

and check clearance between mounting
bosses on cases and frame and any other
areas where frame and cases may contact
each other. Bolts may be difficult to install if
contact is severe.

5. If cases contact frame, remove them and

relieve just enough material in offending area
to provide clearance.

6. Place cases in frame, install one rear mounting

bolt and snug nut.

7. Measure gap between crankcase mounting

bosses and frame motor mounts with feeler
gauge to determine if shimming is required.

8. If gap exists, fabricate shim just thick enough

to fill gap

9. Install opposite corner shim and mounting bolt

and nut, and tighten identical to other bolt.

10. Check other corners with feeler gauge to

confirm thickness required is same as before.
If not, determine cause and correct.

NOTE - S&S Twin Cam style crankcase installation in
Evolution style motorcycle frame is essentially the same as
stock, although additional clearancing and shimming may
occasionally be required. When this style of case is solid
mounted instead of rubber mounted, additional care must
be taken in installing the case. Main areas of concern are
between cases and frame motor mounts. Checking
clearance around and between case mounting bosses and
frame is necessary to insure that crankcase rests squarely
on motor mount pad and no stress is applied to crankcases
when mounting bolts are tightened. Shimming may be
required to compensate for variances between frames.

E. Engine Assembly

NOTES:

●

S&S supplies Torco Engine Assembly Lube with each
Engine. It should be used as specified in following
instructions. While other brands of assembly lube are
acceptable, other lubricants are not. In no instance should
an aerosol lubricant be substituted for assembly lube.

●

While S&S has made every effort to insure that parts are
correct, it is the engine builder’s responsibility to confirm fit
and finish of all parts provided with Engines prior to
assembly. Parts are deburred at S&S and usually require
no further preparation, but must also be inspected by
installer. Individual parts should not be removed from
protective plastic wrappers until needed. After removal
from plastic, it is imperative that parts be thoroughly
cleaned and dried, preferably with compressed air. When
present, rust preventative must be completely removed.
Additionally , gaskets must be closely inspected for particles
that could become dislodged and damage engine. If
assembly of Engine must be interrupted, seal openings and
cover engine with plastic to protect from destructive
contaminants.

Picture E2

Picture E1