S&S Cycle Cylinder Heads for Harley-Davidson Twin Cam 88 Engines - Manual (Page 2)

Disclaimer:
S&S ® parts are designed for high performance off road, racing
applications and are intended for the very experienced rider
only. The installation of S&S parts may void or adversely effect
your factory warranty. In addition such installation and use may
violate certain federal, state, and local laws, rules, and
ordinances as well as other laws when used on motor vehicles
used on public highways, especially in states where pollution
laws may apply. Always check federal, state, and local laws
before modifying your motorcycle. It is the sole and exclusive
responsibility of the user to determine the suitability of the
product for his or her use, an the user shall assume all legal,
personal injury risk and liability and all other obligations, duties,
and risks associated therewith.
Introduction
S&S Super Stock ® cylinder heads are designed to fit all Harley-
Davidson ® Twin Cam 88 ® engines. S&S heads can be used on stock
88”, 3 3 ⁄
4
” bore engines as well as 95”, 3 7 ⁄
8
” bore engines and all
S&S 4” bore dual cam engines. The exterior dimensions of these
heads are similar to stock and require no additional clearancing
when replacing stock heads on engines installed in stock chassis.
The combustion chambers are compatible with stock flat topped
pistons and S&S pistons. Some S&S pistons are flat topped and
some have a “pop up” dome to increase compression. Spark plug
holes are in the stock location and machined to accept stock
spark plugs.
Special Features of the Major Kit Components:
G The intake and exhaust ports are a “cast to shape” design
that yields approximately 30% more flow than stock heads.
G The special intake manifold required for these S&S cylinder
heads has larger 1.780” I.D. runners to match the larger
intake ports on the heads.
G The valve train components are designed to improve flow
and work with any present day fuel. Clearances are set for
any S&S camshaft with a lift of up to .640” without
modification. S&S cylinder heads with the newer style short
breather passage work only with S&S rocker covers. S&S
rocker covers are compatible with stock rocker arms or
aftermarket roller rocker arm assemblies.
G All S&S cylinder heads for Twin Cam 88
® with 89cc
combustion chambers are machined to accept the S&S
compression release. Compression release machining is
optional on heads with the 79cc combustion chamber.
Installation of S&S electric compression releases requires the
use of S&S die-cast rocker covers or similar rocker covers with
a central hole or chimney.
If heads are machined for
compression release, but compression release is not used, a
special plug #90-4916 must be installed in compression
release hole in each head.
G The S&S cylinder heads for Twin Cam 88
® have been
strengthened with additional material in key areas. One
such area is around the head bolt holes on the spark plug
side. The head bolt washer pads for the two “outboard”
head bolts is at the same level as the head bolt pads under
the rocker cover. As a result, S&S heads for Twin Cam 88
® use
four identical long head bolts in each head instead of two
long and two short head bolts.
Kit Contents:
G One set of S&S Super Stock
® cylinder head assemblies
complete with valves, valve springs, valve guide seals and
keepers installed.
G Hardware which includes exhaust port stud flanged nuts,
manifold mounting screws and washers, intake manifold
O-ring seals, and exhaust pipe gaskets.
G Installation instructions.
Additional items required for installation:
Some of these items are included in S&S Hot Set Up Kit
TM or Super
Sidewinder ® packages. If the below items are not listed in the kit
contents, they must be purchased separately.
G S&S rocker covers.
G S&S intake manifold.
G Rocker cover gaskets, cylinder head and base O-rings,
exhaust pipe gaskets and pushrod tube and alignment
dowel O-rings.
G Head gaskets.
NOTES:
G Since it is nearly impossible to anticipate every possible
engine combination, it is the engine builder’s responsibility
to check for proper running clearances. S&S considers
checking and establishing all running clearances as standard
engine building practice that must be performed during
engine assembly. Engine failure due to improper clearances
between moving parts is not covered under warranty.
G Valve pocket reliefs in stock Harley-Davidson
® pistons are
smaller than those in S&S pistons. Valve to piston clearance
should be checked if S&S heads are used with Harley-
Davidson
® pistons and high lift cams. If S&S heads have not
been decked, valve to piston clearance is normally adequate
with cams such as the S&S 585G, with TDC lifts of up to
.186”/.179”. If cams with higher TDC lifts are used, clearance
must be checked.
G If S&S heads are used with S&S pistons no valve to piston
clearancing is normally required.
G If S&S 79cc heads are decked, valve to piston clearance
should be checked. If Harley-Davidson ® pistons are used with
S&S heads that have been decked, valve pockets must be
modified in nearly all cases.
G S&S cylinder heads with 79cc combustion chambers have
smaller valves than the heads with 89cc chambers. Heads
with 79cc chambers have 1.940” intake and 1.575” exhaust
valves. Heads with 89cc chambers have 2.000” intake valves
and 1.605” exhaust valves.
G Due to the larger valve sizes in S&S cylinder heads with 89cc
chambers, the 89cc heads, will nearly always require valve to
piston clearancing if used with Harley-Davidson
® pistons. No
clearancing will be required if used with S&S pistons.
G Other S&S products such as adjustable chrome moly
pushrods, cams, Hydraulic Lifter Limited Travel kit, and Super
E and G carburetors which may enhance the operation of
S&S Super Stock cylinder heads may be purchased separately.
In some instances many of these parts are sold with S&S
heads as part of a Super Sidewinder big bore kit or one of
our popular Hot Set Up Kits.
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