Bentley R Type - Fuel Gauge; The Carburetters (Action)

48
TnB
'R'
TypB BBNrrBv.
Fuel
Gauge.
T-rr: $.t
gauge
registers
when
the
master
and ignition
switches
are
rrOn".
As
mentioned
on
page
43,
this
gauge
also registers
the amount
of
oil
in
the
engine
sump,
when
the appropriate
sriitch is
depressed.
The
Ganburetters
(Action).
Two carburetters
of
the
conventional
S.U. type are
fitted
as
sfrown-in.Figs.
13
and
14,
one
being
shown
in
section to illustrate
the principal
parts.
This
lyp.
of
carburetter
automatically
adjusts both
its choke
and
jet
area
in
accordance
with the
demand-of tire
engine as
determined
bv
.th9
degree
of
throttle
opening,
the
engine
spted, and
the load
against
which
the
engine
is
-operating.
Fie.
I3.-CARBURETTERS
lN POSITION
ON
ENGINE.
1. Fuel inlet
and filter,
2. Air
valve
chamber.
3. Hydraulic
piston.
4, Soienoid.
5. ldle Adiustment
screw.
This is
effected
by
using
the
manifold depression
to levitate
a
piston
or
air valve
carrying
a tapered
needle
which
regulates
the
fuel
p-ass_age.
Tfre, uppgr
side
of the piston
is connected by passage
ways
to
the
base
of the piston
facing
the throttle
valves, and
is thus
subject
to the
$epression
in
the
thiottle
body.
As the
air flow
through
the carburetter increases,
so the
depression
b_etwe.en
the
piston
and
the
throttle valve increases, therebytausing
the_piston
to
rise
and
admit
more air, and
consequently
the
needle
to be
withdrawn
from
the
jet,
thus
allowing
inore
fuel
to
flow.
Similarly,
as
thg
air
flow
falla, due to
reduced engine
requirements,
so
the
piston
fallg, maintaining
a
state of
balance wherebythe
piston
keeps
at a
certain height,
dependent on
engine
speed
and
thlottle
opening.
An approximately
constant
air velocity,
and
hence
an