Service manual
6
NOTES
●
Objective of this modification is to alter 1948-1962 and
1966-1969 crankcases to 1973-later style oiling. With this
oiling system heads and lifters get primary, unrestricted oil
supply first. Lower end main and rod bearings get secondary,
low pressure oil after top end is supplied. This modification
is recommended only if hydraulic lifters are used.
●
1948-1969 style S&S crankcases feature special
machining leaving installation of plug as described in Section
4-D only step required to complete modification.
●
1963-1965 and other Panheads with outside oilers cannot
utilize Step #4, Optional Crankcase Modification, due
different oil supply system.
CAUTION - If performed on “outside oiler” Panheads,
modification described in Step 4 will result in oil starvation
to top end and extensive engine damage.
A. Wrap masking tape around .203" (
13
⁄64") drill bit .850"
from point to use as depth guide. Carefully drill hole
in Picture 11 .850" deep. See Pictures 11 and 12.
NOTE - Drill size is very close to hole size and may tend to
distort hole if drill is not steadied.
CAUTION - Distorting hole may cause poor thread fit after
hole is tapped.
Picture 10 Picture 12Picture 11
Picture 13 Picture 15Picture 14
threads just as it becomes flush with or slightly below oil pump
gasket surface.
C. Install
1
⁄4 -20 set screw using Loctite on threads.
3. Crankcase Modification - 1970-1980 Only - Drill
Pressure Valve Relief Hole.
A. Install S&S Oil Pump Drill Jig, part #53-0013, or H-D
Crankcase Oil Passage Drilling Jig, part #94461-81
or #94461-82, on oil pump gasket surface of
crankcase.
B. Use .125" (
1
⁄8") drill bit to drill pressure relief hole into
gear cavity. See Picture 10. Apply grease to bit and
both sides of case and withdraw drill frequently during
procedure to clear chips.
CAUTION - Do not perform Step 3 on stock 1936-1969
crankcases or any crankcase with angled tappet screen.
Drilled passage will intersect tappet screen oil passage
resulting in loss of oil pressure. Loss of oil pressure will
likely result in serious engine damage due to inadequate
lubrication.
4. Optional Crankcase Modification - 1948-1962 using
#31-6001 cast or #31-6040 billet pump body, or
1966-1969 using #31-6001 or #31-6073 cast pump
body - Plug and Redrill Crankshaft Feed Hole.