Perkins L4 Workshop Manual - L-36 Fleet

.
c Settings
""'Oc
...,
L4 MARINE (W)
and Data.
Maximum Rating- 58 B.H.P. at 2,000 r.p.m.
Sump Capacity - ] gallons (13.6 litres).
Engine Types.
There are two principal types of L4 Marine
~ngine, one type having pneuma tic governing
and the other ha ving mechanical governing.
The standard pneumatic governing is set tor
variabie speed which is controlled by a lever from
the air intake venturi.
The mechanically governed engine is virtually
identical to its pneuma tic governed counterpart,
the one main difference being the mechanica!
governor incorporated in the timing gear housing.
This governor also is of variabie speed and is
controlled by a lever on the side of the governor
housing forward of the fuel injection pump.
Gearboxes.
The 1..4 Marine engine may be fitted with either
a mechanicalor hydraulic operated gearbox.
[n bath cases the drive to the gearbox is taken
from an input shaft fitted to the engine flywheel.
Lubrication of the mechanica I gearbox is by
means of gravity. The gearbox possesses its own
sump from which the oil is picked up by a rotating
disc and de!ivered to a drip plate at the top of
the gearbox which passes the lubricant to the
working parts.
The hydraulic gearbox incorporates its own
oil pump and is in no war dependent on the
engine tor its oil supply.
Where an oil operated gearbox is fitted to an
engine employing pneumatic goveming, a single
lever throttle con trol system may be incorporated
linking the gearbox to the engine throttle. By this
means gearbox engagement is determined by
movement of the throttle lever. With the engine
idling, initial movement of the throttle lever
effects complete engagement of the gearoox without
increasing engine speed. Engine r.p.m. may
then be increaseri by further opening of the
throttle con trol lever beyond a predetermined
point.
Thus the engine cannot be speeded in neutra!
gear, thert'by eliminating the risk of damage when
the gearoox is engaged. When changing trom
L4 MARINE ENGINES-W.l
ahead to astern or vice versa. the engine throttle
must pass through the idling position. thus enabling
an easy gear change to be attained.
In conjunction with tbis control system. provision
may be made for the fitting of a cable to the
throttle so that the throttle may be partly opened
to assist easy starting.
When an oil operated gearbox is fitted. an oi]
cooler must be fitted in order to cao] the gearbox
oil. The mounting for this cooler is on the top
of the gearbox.
An inter-locking control may afso be used in the
case of a pneumatically governed engine fitted
with a mechanica! gearbox.
The system employed ensures that the engine
throttle is automatical]y returned to id]ing when
the gear lever enters the neutral position. An
amp]e measure of protection is thus afforded
the gearbox. inasmuch as when engaging or
changing gears. the engine throttle must alway~
be in or pass through the idling position. However
with engines utilising mechanica] governing,
irrespective of t~ type of gearbox fitted. there is
no system of Iinkage offered whereby the gearbox
may be effectively coupled to the engine throttle
controls.
Reduction gears of 2: 1 and 3: 1 fot Ieft or
right hand rotation propellors. may be fitted as
optional equipment.
N.B. When converting a mechanical gearbox
from stra ight through drive to 2: I or 3: 1
coupling at the rear of the box must be replaced
reduction. the split type balI race behind the
by a standard type of balI race.
Gearbox and Input Shaft Removal.
Both types of gearbox may be removed in the
following manner :-
Disconnect propellor shaft.
Remove 12 setscrews and was hers located
around gearbox periphery.
Withdraw gearbox trom input shaft.
The input shaft which is affixed to the engine
flywheel may be removed as follows :-
Cut locking w ire.