Sunbeam ALPINE I SERIES: APLINE II SERIES, Workshop Manual

Page: 85 / 413

RO OTES MAN UAL WSM. 12-4
Section B (Engine)
Page 47
Fig. 55.
Closed crankcase ventilation
system.
CLOSED CRANKCASE VENTILATION
SYSTEM
This crankcase ventilation system i� fitted to the
engines of cars supplied to areas where regulations
forbid the discharge of crankcase fumes direct Into
the atmosphere.
Description See Fig.
55
The system consists of hoses (I) (2) and ( 4), a
flame trap (3), and ventilation regulator (5) the
outlet end of which is screwed Into the inlet
manifold.
Details of the regulator valve are shown In the
Illustration Inset. It consists of an outlet con­
nection (6) screwed into the main body (9) that
houses the valve (7) and the valve opening spring
(8).
The flame trap
(3)
was not fitted to the first arrange­
ment of this system which had a direct hose connection
from the oil filter tube on the rocker cover to the
ventilation regulator
(5),
and a crankcase air Intake
gauze filter which screwed into the tappet chamber
cover. Particulars
of
the first type
of
regulator valve
were given In section
C
page
59.
Operation
When the engine is idling the Inlet manifold
depression is high enough to draw the regulator
valve (7) onto its seat (10), and under this condition
crankcase fumes pass directly Into the carburettor
through the pipe (2) flame trap (3) and pipe (4).
As the throttle opens the Inlet manifold de­
pression decreases and the spring (8) lifts the valve
(7) from Its seat. This allows the crankcase fumes,
and air to be drawn from the tappet cover through