S&S Cycle Replacement Pistons 80 For Harley-Davidson Evolution Big Twin Engines - Manual (Page 3)

d. Install oil rings - Oil rings are three piece type with two rails and
one expander. Do not shorten expander for any reason! Installation
is straightforward with one rail placed above expander, other rail
below expander. Rails may be shortened to correct gap, but burrs
must be carefully removed. Expander gap must be in center of
thrust face (rear of piston), or 90° from wristpin. Bottom rail gap
should be approximately 1.5" or 45° to right of expander gap. Top
rail gap should be approximately 1.5" or 45° to left of expander gap.
NOTE: Confirm that ends of expander do not overlap during installation.
Properly installed expander will appear larger than piston but will
compress when cylinder installed.
e. Install second compression ring - Second compression ring has a
darker, charcoal gray finish and slight bevel along inner surface.
This ring has a dot. See Figure 1. Install in second or middle groove
with dot up. Second compression ring gap should be 135° or
approximately 11⁄2" to right of oil expander gap.
f. Install top compression ring - Top compression ring has a gray finish
that is relatively light in color, and may or may not have a slight
bevel along the inner edge. It has no dot or other identifying mark.
The light color can best be recognized by comparing compression
rings to each other beneath a good light. Install light colored ring
without dot in top groove, bevel up. If there is no bevel, ring can be
installed either side up. See figures 2 and 3. Top compression ring
gap should be 135° or approximately 11⁄2" to left of oil expander gap.
Incorrect installation of rings may result in poor performance,
excessive oil consumption or engine damage.
5- Cylinder Installation
a. Apply assembly lube or motor oil to the skirts of the piston and to
the piston rings.
b. Place ring compressor around piston so that the rings are fully
compressed in their respective grooves.
c. Slide cylinder over piston, making sure that rings do not come out
of the grooves, and that ends of oil ring expander to not overlap.
d. Remove ring compressor and repeat for other cylinder.
6- ENGINE BREAK-IN PROCEDURE
a. Initial start up. Run engine approximately one minute at 1250–
1750 rpm. DO NOT crack throttle or subject to any loads during
this period as head gaskets are susceptible to failure at this time.
During this time check to see that oil pressure is normal, that oil is
returning to the oil tank, and that no leaks exist.
b. Shut off engine and thoroughly check for any leaks or other
problems. Let engine cool to the touch
c. After engine has cooled, start up again and allow the motor to
build some heat. Engine should be run no longer than three to
four minutes. When the cylinders become warm/hot to the touch
(approximately 150°) shut the motor down and let it cool to room
temp. Follow the same cautions as for the initial start-up, and
continue to watch for problems.
d. Repeat this procedure 3 or 4 times. Each successive time it should
take slightly longer to warm up and you can increase the temp
slightly each time (+10°). You can be more liberal each time with
the rpm, gently vary rpm continuously from idle up to 2500 rpm
in the final cycle. Don’t be too concerned with final carb settings
at this time because idle speed and mixture cannot be correctly
set until the motor reaches full operating temperature. The motor
should not reach that temperature during these cycles. Do not
allow engine temperature to become excessive. After the motor
has cooled to room temperature for the final time you are ready to
start the 500 mile engine break-in process.
e. The first 50 miles are most critical for new rings and piston break-in.
Engine damage is most likely to occur during this period. Keep heat
down by not exceeding 2500 rpm. Avoid lugging the motor, riding
in hot weather or in traffic. Vary the engine speed. Do not lug the
engine. We recommend changing the oil at 50 miles.
f. The next 500 miles should be spent running engine no faster than
3500 rpm or 60 mph. Avoid continuous steady speeds, and do not
lug the engine. Vary engine rpm. We recommend changing the oil
again at 500 miles.
Lugging or running engine prematurely at sustained high rpm
may result in damage to pistons and other engine components.
S&S® voids its guarantee if engine is not broken in properly.
g. For the balance of the first 1000 miles the motor can be run in a
normal but conservative manner. You can be more liberal with the
rpm range and motorcycle can be operated at normal highway
speeds. Avoid overheating or putting any hard strain on the engine:
no drag racing, dyno runs, excessive speed, trailer towing or sidecar
operation.
h. After 1000 miles, change the engine oil. Motorcycle can now be
operated normally.
i. Have Fun!
3
CAUTION
CAUTION
Figure 1 Figure 2 Figure 3