Royal Enfield 500 TWIN 1949 Workshop Maintenance Manual page 11

ROYAL ENFIELD WORKSHOP MANUAL
W - delivery to rocker gear.
X - delivery to big ends.
Position 1. The plunger A is being drawn out of
the cylinder hole in the disc C by the action of the peg
B on the shaft D. The port T in the disc C registers
with the suction port Y in the housing, so that oil is
drawn into the cylinder from the oil tank. At the same
time the delivery port W in the housing is uncovered
and oil below the disc in the housing is forced through
W to the rocker gear.
W' - delivery to oil tank.
X' - delivery to oil tank.
Position 1. The plunger A' is being drawn out of
the cylinder hole in the disc C' by the action of the
peg B' on the shaft D'. The port T' in the disc C'
registers with the suction port Y' in the housing, so
that oil is drawn into the cylinder from the crankcase
sump. At the same time the delivery port W' in the
housing is uncovered and oil below the disc in the
housing is forced through W' back to the oil tank.
Section B1 Page 4
The ports in the housing are connected as follows
The ports in the housing are connected as follows :
Y - suction from oil tank.
Z - suction from oil tank.
Position 2. The plunger A is being pushed into the
cylinder hole in the disc C. The port T in the disc
now registers with the delivery port X in the housing,
so that oil is forced out of the cylinder to the big
ends. At the same time the suction port Z in the
housing is uncovered and oil is drawn into the
housing below the disc from the oil tank.
Y' - suction from crankcase.
Z' - suction from timing chest.
Position 2. The plunger A' is being pushed into the
cylinder hole in the disc C'. The port T' in the disc
now registers with the delivery port X' in the housing,
so that oil is forced out of the cylinder back to the oil
tank. At the same time the suction port Z' in the
housing is uncovered and oil is drawn into the
housing below the disc from the timing chest.
(On early models Y'
and Z' were reversed)