S&S Cycle Piston and Big Bore Kits 98 and 107 for 1999-06 and 2007-14 Big Twins - Manual (Page 3)

d. The top ring must be installed with the “N" facing up (see Picture
4). The top ring will have a chamfer on the inside edge, this chamfer
will face up. Use a ring expander tool to install the ring to the top
groove. Orient the gap according to Picture 5a.
3. Piston Ring Installation
Order of installation
1. Oil ring expander (ends must face up as shown in Picture 3)
2. Oil ring rails
3. 2nd ring-cast iron with a taper underhook groove face, letter “N"
faces up
4. Top ring-steel compression ring that has been gas nitride, letter “N"
faces up
a. Install the oil ring expander to the bottom groove of the piston.
The expander ring has a silver finish. Make sure the end of
the expander ring is butted together and not overlapping
(Picture 3, below). If the tips are overlapped, excessive oil
consumption will occur. Orient the expander gap such that
it can be viewed as it enters the cylinder. See Picture 5c.
b. Install oil rails. The oil rails are the thinnest of all the rings. Either
side can be placed up. Install the rails into the groove by hand.
Install one rail above the expander, and one below. Orient the gaps
according to Picture 5a.
c. Install the 2nd ring with the “N" facing up (see Picture 4). Use an
expander to install the ring to the 2nd groove in the piston. Orient
the gap according to Picture 5a.
Top Ring Gap
Expander
Ring Gap
Top Oil Rail Gap
Second Ring Gap Bottom Oil Rail Gap
C
AM
SI
D
E
DR
IV
E S
IDE
3
Picture 1
TOP RING
2 nd RING
Picture 4
Picture 5a
Picture 5b
Picture 5c
Expander Ring Gap
Picture 2
Picture 3