S&S Cycle Bore Stroker Kit 3 3/16 for Harley-Davidson Sportster Models - Manual (Page 3)

NOTES
●
Oil rings will usually touch and/or cross oil return holes with
installation of stroke 4
7 ⁄
16
” or longer. Strokes shorter than
4 7 ⁄
16
” do not require this step.
● Method given below was tried as an experiment when we
installed an S&S
® 4 5 ⁄
8
” stroker kit in our 1972 model. All steps
except H and I were performed. Object was to see if engine
would smoke and use excessive oil which it did not. Several
customers have also reported similar successes when leaving
stock holes open. Based upon our test results and these
customer reports, we feel relatively confident in
recommending that stock oil return holes be left open even
though we have tried it on only one test engine and cannot
guarantee that it will work in all instances. If you decide to
try leaving the stock oil return holes open, perform all of the
following steps except H and I.
For strokes 4 7 ⁄
16
” and longer, perform following steps:
A. Place cylinder with head gasket surface down on bench.
Lay out lines “A” on cylinder base gasket surface so they
are directly above centers of old oil return holes which
exit into cylinder bore. See Figure 1.
B. Lay piece of 1 ⁄
8
” thick material against cylinder spigot 90°
to lines A and scribe lines “B”.
C. Center punch points where lines A and B intersect.
D. Drill 3 ⁄
16
” diameter hole at each point perpendicular to
gasket surface to meet passage coming from cylinder
head. Be careful not to break drill when breaking into
existing passage as holes may be slightly misaligned and
drill may tend to grab.
E. Center punch corners where lines A intersect spigot.
See Figure 2.
F. Drill 3 ⁄
32
” diameter hole at each point at 60° angle into
cylinder bore.
G. Enlarge 3 ⁄
32
” holes from inside cylinder bore with 3 ⁄
16
”
diameter drill.
H. Braze or weld old oil return holes shut. .
NOTE - Be sure person who does work knows how to work with
cast iron as cylinders may crack or develop hard spots if not done
properly
I. Repeat step D to remove braze or welding material that
may be obstructing oil return passages.
J. Blow air through passages to remove chips, etc.
Dirt, filings, etc. left in oil return passageways may circulate
in oil damaging other parts possibly causing engine failure.
● Some solvents, degreasers, gasoline and other chemicals are
harmful to skin, eyes and other body parts. Many items are
flammable and present a fire hazard. Read manufacturer’s
instruction label for proper use. Use in well ventilated area
and wear protective clothing when using them to avoid
personal injury.
● Compressed air and particles dislodged by compressed air
are harmful to eyes and body. Wear protective goggles
when using compressed air and always direct air stream
away from body parts such as hands and eyes and other
people near you.
3
Centerpunch, then
drill 3 ⁄
32 " diameter hole
Figure 2
Picture 2 Picture 3
CAUTION
WARNING
Center-punch, then drill 3 ⁄
32
”
diameter hole