Caution – S&S Cycle Valve Spring Kits for 1984-2004 Big Twin & 1986-2003 Four-Cam (90-2077 and 90-2078) User Manual

Page 2

S&S

valve spring and collar kits #90-2077 and 90-2078

accommodate valve lifts up to .640” using standard length,

⁄

”

diameter valves, and are compatible with stock style valve
guides and valve guide seals. These spring kits are included
with S&S Super Stock

cylinder heads for Harley-Davidson

Evolution

and Twin Cam 88

engines.

NOTES
●

Spring kit components are not interchangeable with those
from other S&S valve spring kits.

●

Titanium top collars supplied with kit #90-2078 do not
require steel wear plate used with previous S&S
titanium collars.

Mixing of valves, springs or collars between early and late
S&S high-lift kit can cause extensive engine damage not
covered under warranty.

Installation of 90-2077 or 90-2078 spring kits does not usually
require modification for S&S or most stock heads. Exceptions are
Buell

Thunderstorm heads and certain Sportster

models and

big twin heads with different machining in valve spring pockets.
In such cases, removing a small amount of material
(approximately .030”) from O.D. of S&S bottom collar should
allow collar to rest flat in spring pocket for correct installation.
It may be necessary to machine the valve spring pocket deeper
to achieve the correct installed height when installing springs in
Twin Cam 88

cylinder heads.

90-2077 and 90-2078 spring pressures are as follows at 1.800”
installed height: Closed valve - 171 lbf; .560” lift - 389 lbf; .630
lift - 416 lbf.

Spring Installation Procedure

1. Remove heads from engine and disassemble. If cylinder

heads/valves are to be reconditioned, proceed at this time
according to standard procedure. Refer to Harley-Davidson

service manual as necessary.

2. Place lower spring collar in valve spring pocket in head. Place

outer spring on collar. Collar must sit flat on cylinder head
and spring coils must not contact sides of spring pocket in
head. If necessary, machine lower collar and/or spring pocket
to obtain minimum clearance of .030”. Do not modify spring
in any way.

Using following procedure, determine installed spring
height and clearance between top collar and valve guide.

A. Lubricate valve stem and install valve in guide.

B. Install bottom collar, valve seal, top collar, and valve

keepers. Pull top collar tightly against keepers to seat
keepers in collar.

C. While holding valve firmly against seat in closed

position, measure installed spring height (distance
between lower valve spring seating surface and outside
step of top collar). See Figure A, Dimension A. Record
measurement.

D. Measure distance between top collar keepers and top of

valve guide or seal (if applicable). See Figure A,
Dimension B. Distance must be at least .060” greater
than valve lift of cam to be used. If dimension B is not
.060” greater than valve lift, valve guide must be
shortened to obtain required clearance.

Remove seal and grind

guide here to obtain

greater measurement B.

Dimension A:
Installed spring height must be adjusted to 1.800" ± .020"

Dimension B:
Must be .060" greater than valve lift for camshaft to be used.

Figure A

CAUTION