engine JEEP DJ 1953 Service Manual

'Jeep9
UNIVERSAL
SERIES
SERVICE
MANUAL

E-59.
Fuel
Pump Installation

a.
Make certain mating surfaces of fuel pump and
engine
cylinder case are clean. Cement a new gasket
to mounting
flange
of fuel pump.
b. Position fuel pump on cylinder block, so that

cam
lever of pump rests on fuel pump cam of cam­
shaft. Secure pump to block with two cap screws

and
lock washers.
c. Connect intake and
outlet
fuel lines to fuel
pump.

E-60.
FUEL
PUMP
(SINGLE-ACTION)
—
HURRICANE
F4
ENGINE
•
Late
Models.

The
Hurricane F4
engine
is equipped with a single-
action fuel pump (Fig.
E-31).
The fuel pump cam lever is activated by an eccentric on the
engine

camshaft. When the carburetor float
needle
valve
closes, accumulation of fuel in the pump
extends

the diaphragm spring.
This
action causes the rocker

arm
linkage to
become
inoperative until the pres­
sure on the diaphragm and spring is reduced. The fuel pump discharge pressure is thus controlled by
the diaphragm spring.
This
provides a steady sup­ ply of fuel to the carburetor at a fairly constant
pressure.

E-61.
Fuel
Pump Removal

To
remove the fuel pump from the
engine,
dis­
connect the inlet and
outlet
fuel lines. Remove
the two fuel pump
body
attaching nuts, lock washers, and washers, and pull the fuel pump and
gasket free of the
engine.

E-62.
Fuel
Pump Disassembly

Note:
The fuel pump is serviced with a repair kit.

Individual
service parts are also available. The
valves are not replaceable but are serviced as part
of the valve housing.

•
Refer to Fig. E-32.

a.
Remove filter bail assembly, bowl,
element,

spring,
and gasket from filter cover. b.
File
a locating
mark
on the
edges
of the valve
housing and the pump body. Remove the six at-

14280
FIG.
E-32—FUEL
PUMp—

HURRICANE F4 ENGINE,
LATE
MODELS

12988

FIG.
E-31—FUEL
.PUMP-

HURRICANE F4 ENGINE,
LATE
MODELS 1—
Bail

2—
Bowl

3—
Spring

4—
Filter
5—
Gasket

6— Pump Body 7—
Gasket

8—
Valve
Assembly 9— Screws 10—
Valve
Housing
11—
Valve
Assembly
12— Screws
13—
Diaphragm
and Oil Seal 14— Pump Body
15—
Cam
Lever
Spring 16—
Cam
Lever

17—
Gasket

18—
Cam
Lever
Pin and Plug 129

E

FUEL
SYSTEM
taching screws and valve housing from the fuel
pump body.

c.
Remove the two screws in the valve housing
and
separate the filter cover and air
dome
dia­
phragm.

d.
Remove the cam lever return spring, plug,
cam
lever pin, and cam lever from the pump body.

Tap
the cam lever pin out of body, using a drift
inserted through the small
hole
in the pump body.
e. Remove diaphragm from pump body.
f. Under normal service, the pump may be cleaned without further disassembly.

Note:
The oil seal (at top of spring in diaphragm
assembly) seals the spring side of the fuel
dia­
phragm
from the crankcase. Any deposit, in
excess

of a few drops, of oil on the diaphragm indicates leakage past the oil seal. Be sure the seat for the

seal
in the pump body is clean and smooth.

E-63.
Fuel
Pump Cleaning and Inspection

Caution:
Do not immerse valves or diaphragm
in
cleaning solvent; wipe clean.

Clean
all metal parts of the fuel pump in solvent.
Brush
with a stiff-bristled
brush.
Dry with com­
pressed
air.
Check
all parts to see that they are not
cracked
or broken and that the screw threads are
not damaged.

E-64.
Fuel
Pump Reassembly
•
Refer to Fig. E-32.

a.
Assemble the valve housing and filter cover, using a new air
dome
diaphragm. The opening

in
the air
dome
diaphragm is located over the
intake
valve. The filter cover is positioned cor­
rectly
when the inlet passage in the cover aligns

with
the inlet valve. Tighten the attaching screws
alternately and securely.

b.
Lubricate
diaphragm assembly shaft, around

oil
seal, with
engine
oil. Position diaphragm as­ sembly on valve housing and thread all the attach­ ing screws through diaphragm.
(This
helps avoid
damage to the screw
holes
in diaphragm.)

c.
Place diaphragm assembly and valve housing
in
position on pump body (align marks made
before disassembly).
First
start all screws one

or
two threads; then tighten the screws alternately

and
securely.

d.
Lubricate
forked end of cam lever, pin bore
of body, and corresponding
hole
in lever, and the
pin
itself with
engine
oil.

Note:
Forked
end of lever
goes
around diaphragm
shaft. Be sure
loose
bumper washer on diaphragm shaft is on top of lever and
between
lever and fixed
washer
on shaft.
e.
Install
lever and pin. To install pin, use a drift
and
tap pin into the
hole
in the body until it hits
the
stop
on the
bottom
of the hole;
move
the lever while tapping, to align
hole
in lever with the pin;
then install plug.
Install
lever return spring.
f.
Install
a new filter bowl gasket in filter cover.
Place
bail
assembly in ears on cover and swing
to one side.
Install
spring and new filter element in
bowl and install bowl on pump. Position
bail
as­
sembly under bowl; tighten retainer screw.

Caution:
Do not overtighten screw.

E-65.
Fuel
Pump Installation

a.
Make certain mating surfaces of fuel pump and

engine
cylinder case are clean. Cement a new gasket to mounting flange of fuel pump.

b.
Position fuel pump on cylinder block, so that

cam
lever of pump rests on fuel pump cam of cam­
shaft. Secure pump to block with two cap screws
and
lock washers. Torque
bolts
13 to 17 lb-ft. [1,8
a
2,3 kg-m.].

c.
Connect intake and
outlet
fuel lines to fuel
pump.

E-66.
Fuel
Pump Testing

Whenever
the fuel pump is to be checked for pres­

sure
or volume, follow the procedure outline in

Par.
C-23 of this manual.
Fuel
pump pressure is
important
for low pressure
will
seriously affect en­

gine
operation and high pressure can cause exces­
sive fuel consumption and flooding of the carbure­
tor.
Should there be any doubt of normal opera­
tion, check the procedure as outlined in Par. C-23.
In
addition to proper fuel pressure, volume of the
pump is also important. When testing for proper
pump pressure, be certain to also
test
for volume
as the pump may build up sufficient pressure, but
fail
to produce sufficient volume.

E-67. FUEL
PUMP
—
DAUNTLESS
V-6
ENGINE

Jeep vehicles equipped with the Dauntless V6-225

engine
have a special fuel pump which has a metering
outlet
for a vapor return system. Any

vapor
which forms is returned to the fuel tank
along with hot fuel through a separate line along­
side the fuel supply line.
This
greatly reduces any
FIG.
E-33—FUEL PUMP—DAUNTLESS V-6 ENGINE
1
—Fuel
Outlet 2—Vapor
Return
3—Fuel
Inlet

130

'Jeep'
UNIVERSAL SERIES SERVICE
MANUAL

E
possibility of vapor lock by keeping cool fuel from
the tank constantly circulating through the fuel
pump.

Fuel
pump pressure at carburetor (inlet) on Daunt­
less
V6-225
engine
should be 3% lbs.
[0,264
kgm-cm2] minimum at idle with the vapor return
hose

squeezed off. With the vapor return
hose
open
pump pressure should be 2j^ lbs. [0,176 kg-cm2]
minimum.

The
Dauntless V-6
engine
is equipped with a sealed

unit,
non-repairable, single-action fuel pump (Fig.

E-33).

Note:
All Dauntless V-6
engines
are equipped with

a
throw-away can-type gasoline filter installed in
the fuel line
between
the fuel pump and the
car­
buretor.
This
unit must be replaced every
12,000
miles
[19.200
km.] of vehicle operation.

E-68.
Fuel
Pump Removal

To
remove the fuel pump from the Dauntless V-6
engine, disconnect the fuel inlet, fuel
outlet
and fuel return lines from the pump. Remove the two
fuel pump body attaching cap screws and lock

washers.
Pull
the fuel filter bracket free and remove the pump and gasket. Discard pump and gasket.
Install
new pump in reverse procedure of removal.

E-69.
AIR
CLEANER

Servicing
of the air cleaner is properly taken care of as part of the periodic lubrication and servicing of the vehicle. For this reason, air cleaner servicing
information is given in the Lubrication Section.

Refer
to and follow the instructions given there.

E-70. ACCELERATOR LINKAGE
The
accelerator linkage is properly adjusted when
the vehicle leaves the factory. However, in time
components parts
will
become
worn and require re­
adjustment to maintain a smooth even control of
engine
speed. On Models equipped with F4
engines

the adjustment is made at the adjusting block,

Fig.
E-34. Loosen the lock nuts, and adjust the length of the accelerator rod so that when the
car­

buretor throttle valve is wide open the accelerator
treadle
will
just strike the toe board. After correct
adjustment is made tighten both lock nuts firmly.
To
adjust the accelerator linkage on V6
engines

loosen
the lock nuts securing the accelerator rod
housing to its securing bracket and adjust the length
of the accelerator rod so that when the carburetor throttle valve is wide open the accelerator treadle

will
just strike the toe board. After correct adjust­
ment is made, tighten lock nut firmly, see Fig. E-35 for Dauntless V-6 engine.

E-71. FUEL
TANK
AND
FUEL LINES
The
following paragraphs (E-70 through E-73) describe the removal, installation and services to
be performed when replacing the fuel tank or
servicing
the fuel system.

FIG.
E-34—ACCELERATOR LINKAGE,
F4
ENGINE
1—
Grommet

2— Nut and Lockwasher

3—
Throttle
Control
4—
Choke
Control 5—
Treadle
Rod Seal
6—
Accelerator
Treadle
7—
Treadle
Hinge Pin
8—
Treadle
Hinge 9— Nut and Lockwasher
10—
Screw

11—
Accelerator
Rod
12— Nut
13—
Adjusting
Block
14—
Retracting
Spring
15—
Cotter
Pin
16—
Lower
Beilcrank
17—
Washer

18—
Beilcrank
Link
Rod
19—
Bracket

20—
Throttle
Wire
Stop
21—
Beilcrank
Spring
22—
Rod

23—
Upper
Beilcrank
24—
Wesher
10731
131

FUEL
SYSTEM

14417

FIG.
E-35—ACCELERATOR LINKAGE—V-6 ENGINE

1— Lever
Assembly

2—
Choke
Rod
3—
-Accelerator
Rod (Upper) 4—
Choke
Control Cable
E-72.
Fuel
Tank

The
fuel tank on early model 'Jeep* Universal vehicles has a capacity of 10}4 gals. [38,75 ltr.] and
is mounted under the driver's seat. The tank is
secured to the front floor panel by a hold down

strap
and two bolts.
The
fuel tank on all late model 'Jeep* vehicles has a
capacity of 16 gal. [60,56 ltr.] and is mounted to
three frame
rail
brackets at the
rear
and center of
the frame. The tank is secured to the brackets by
three
bolts
and six rubber shock insulators. A fuel

tank
skid plate is attached to the
rear
frame cross- member to protect the
bottom
of the tank from damage.
E-73.
Fuel
Tank
Removal

When
removing the fuel tank on early model vehicles, first drain the tank of
all
fuel. Remove the

driver's
seat, then remove the tank hold down

straps.
Disconnect fuel line(s) and sending unit 5—
Accelerator
Mounting Bracket
6—
-Accelerator
Boot
7—
Accelerator
Rod
(Lower)

8—
Accelerator
Treadle
wire
from the tank. Remove the filler neck rubber
grommet and remove the tank assembly from the vehicle.

When
removing the fuel tank, on late model vehicles first
drain
the tank of
all
fuel, then remove
the fuel tank skid plate. Loosen the filler neck and vent tube
hose
clamp and disconnect
hoses
from fuel tank. Remove the three mounting
bolts
and six
washers and rubber insulators that secure the tank to the frame brackets. Loosen frame brackets to
give
clearance for tank removal.
Lower
tank
slightly allowing space for disconnecting fuel and vent lines and sending unit wire from tank.
Lower

tank
and remove from underside of vehicle.
E-74.
Fuel Tank Installation

Note:
On vehicles equipped with the Dauntless

V-6
engine
two luel lines are connected to the fuel

tank;
a fuel out line and a fuel return line. It is im- 132

'Jeep'
UNIVERSAL
SERIES
SERVICE
MANUAL

E
portant that
these
lines are not accidentally re­
versed.

When
installing the fuel tank on late model vehicles, position the tank
between
the frame
rail

to allow space to connect the fuel line(s), vent
hose

and
sending unit wire. After connecting
these
items, align and secure tank to frame brackets.
Position filler
hose
on tank filler neck and tighten
hose
clamp.
Fill
tank with fuel and check for leaks.

When
installing the fuel tank on early model vehicles, reverse the order of removal as given in

Par.
E-73.

E-75.
Fuel
Tank
Cap

A
surge pressure type fuel tank filler cap is used on

all
models.
This
is necessary to prevent fuel leakage
from
the cap vent opening when the vehicle is on a
side slope. Two spring loaded relief valves which
open when venting is required are built into the
cap.
Should the pressure valve
fail
to open, pressure
in
the tank may force fuel by the carburetor inlet
valve causing flooding.
Failure
of the vacuum valve may prevent flow of fuel to the carburetor. Should
the valves
fail
to vent install a new cap.

Note:
Vehicles having a
Fuel
Evaporative
Emis­

sion System are equipped with a non-vent sealed gas cap. The sealed cap is designed to allow no
vapors to discharge to the atmosphere. No other type of cap is to be used on vehicles having this
type system.

E-76.
Fuel
Gauge Float Unit

The
fuel tank
gauge
float unit is mounted in the top
of the fuel tank and consists of a housing enclosing
a
rheostat that is actuated by the float arm, and a
float
which
moves
with the fuel level in the tank.
On
V-6 and current production F4
engine
equipped vehicles, the fuel
outlet
pipe is integral with the
float
unit.
The fuel
outlet
pipe has a mesh filter on the inner end.

Note:
Under no circumstances should a fuel tank

gauge
be installed without a mesh filter element.

The
filter,
outlet
pipe, and float unit are locked as

an
assembly to the top of the fuel tank. To remove,

turn
the lock plate that secures the float unit
assembly.

E-77.
Fuel
Lines

Check
lines and connections occasionally for leaks,
and
for severe kinks that might restrict the flow of
fuel. If an excessive amount of
dirt
is found in the
carburetor
or fuel pump, the fuel tank should be
drained
and the fuel lines blown out with com­
pressed air.

All
rubber fuel lines and their respective clamps should be checked occasionally to be certain they
are
correctly positioned and not leaking. 133

E

FUEL
SYSTEM
E-78. SERVICE DIHGNOSIS
Symptoms Probable Remedy

Excessive
Fuel
Consumption:
Tires
improperly inflated Inflate

Brakes
drag Adjust
Engine
operates too cold Check thermostat
Heat control valve inoperative Check thermostatic spring
Leak
in fuel line Check all connections

Carburetor
float level high. See
"Carburetor"
section
Accelerator pump not properly adjusted Adjust

Leaky
fuel pump diaphragm Replace
Loose
engine
mountings causing high carburetor fuel level Tighten Ignition timing slow or spark advance stuck See "Distributor" section

Low
compression. Check valve tappet clearance
Air
cleaner dirty
.
Remove and clean

Engine
Hesitates on Acceleration: Accelerator pump
does
not function perfectly.
...................
.Replace piston and rod or adjust
Carburetor
float level. ... .Adjust

Spark
plugs Replace or clean and adjust

Low
compression Check valves

Distributor
points—dirty or pitted Replace

Weak
condenser or coil Replace

Carburetor
jets restricted Remove and clean

Excessive
engine
heat See "Engine" section

Engine
Stalls—Won't Idle:
Improper
condition of carburetor See
"Carburetor"
section

Low
speed
jet restricted Remove and clean
Dirty
fuel sediment bowl screen Remove and clean

Air
cleaner dirty Remove and clean

Leaky
manifold or gasket Replace

Fuel
pump diaphragm porous. Replace
Loose carburetor. Tighten
flange
nuts

Water
in fuel
Drain
and clean system

Improper
ignition. .See "Distributor" section

Spark
plugs Clean and adjust

Valves
sticking.
Grind
valves 134

'Jeep'
UNIVERSAL SERIES
SERVICE
MANUAL

E
E-79.
FUEL
SYSTEM SPECIFICHTIONS
CARBURETOR SPECIFICATIONS HURRICANE
F4 (See
Note)

Make
Model.
Throttle Bore

Main
Venturi.
Low
Speed
Jet

Main
Metering Jet Idle Port

Nozzle
Bleed In Body
Pump Jet
Float
Setting

Engine Idle RPM Dash Pot
Setting
. ......

CARBURETOR SPECIFICATIONS HURRICANE
F4 (See
Note).

Make Model
Throttle Bore
Main
Venturi
Low
Speed
Jet
Main
Metering Jet Idle Port

Nozzle
Bleed In Body
Pump Jet.
Float
Setting
Engine Idle RPM Dash Pot
Setting
Without Exhaust Emission Control

Carter

YF-938SD

lY2n
[3,81 cm.]

1M"
[3,18 cm.]
.028"
[0,711
mm.]

.0935"
dia.
[2,375
mm.]
.184" x .030" [4,70 a
0,765
mm.]
.0225
"[0,571
mm.] .031"
[0,787
mm.] Vk" [7,39 mm.] 600 Without Exhaust Emission Control

Carter

YF-4002-S

\y%"
[3,81 cm.]

1M"
[3,18 cm.]
.031"
[0,794
mm.]
.091" dia.
[2,311
mm.]
.184" x .030" [4,70 a
0.765
mm.] .028"
[0,713
mm.]
.025"
[0,635
mm.]
lW
[6,74 mm.] 650 — 700

With
Exhaust Emission Control
Carter

YF-4366-S,
YF-4941-S, YF-6115-S IV2" [3,81 cm.]

1M*
[3,18 cm.]
.035"
[0,889
mm.]
.089" dia.
[2,261
mm.]
.184" x .030" [4,70 a
0.765
mm.] .028"
[0,713
mm.]
.024"
[0,609
mm.]
1W
[6,74 mm.] 700 - 750
Y%" ]3,75 mm.]

CARBURETOR SPECIFICATIONS
DAUNTLESS
V-6 (See
Note)
Make
Model
Designation
Code Number
Choke
Number of Barrels
Throttle Bore

Main
Metering Jet: Production . . High Altitude —
over
5000
ft
—
over
10,000
ft... .
Float Level Adjustment*
Float Drop Adjustment Pump Rod Adjustment**
Engine Idle RPM
Initial
Idle
Speed
Setting
Initial
Idle Mixture
Setting.

Dash Pot
Setting
Without Exhaust Emission Control
Rochester
2G

7026082
Manual
2
Wy? [3,65 cm.]
.051" - 60° [1,29 mm.]
.049" - 60° [1,24 mm.] .047" - 60° [1,29 mm.]
Hit"
[27,78
mm.] V/%" [4,76 cm.]

IH2"
J2.94 cm.] 650
-—
700 3 turns in
2 turns out
W [3,75 mm.]
With
Exhaust Emission Control
Rochester

2G

7027082-7041185
Manual

2
[3,65 cm.]
.051" - 60° [1,29 mm.]
.049" - 60° [1,24 mm.] .047" - 60° (1,29 mm.] l%2"
[29,36
mm.] V/£" [4,76 cm.]

\W
]2,94 cm.[ 650 — 700 3 turns in
2 turns out
[3,75 mm.]

*From
air horn
gasket
to top of
float
at toe.

**From
air cleaner ring to top of
pump
rod.
NOTE:
Carburetor
specifications
for
engines
equipped
with
exhaust
emission
control are
also
shown
in
section
Fl for the F4-134 Hurricane
engine,
and in
section
F2 for the V6-225 Dauntless
engine.
135

E

FUEL
SYSTEM E-79.
FUEL
SYSTEM SPECIFICATIONS
(Continued)

MODEL
EARLY
MODEL
HURRICANE
F4
EARLY
MODEL
DAUNTLESS
V-6

AIR CLEANER:
Type
Oil
Bath

Oil
Bath

FUEL
TANK: 10H
gal. [39,75 ltr.]
10lA
gal. [39,75 ltr.]

Location
Under
Driver's Seat

Under
Driver's Seat

FUEL
PUMP:
AC
or
Carter
A.C.

Model
5594032
21955

6440515

Type..
Diaphragm,
serviceable unit
Disposable unit

FUEL
FILTER:
Tank
unit only
Left
side of engine, plus tank unit

MODEL
LATE
MODEL
HURRICANE
F4
LATE
MODEL
DAUNTLESS
V-6

AIR CLEANER:
Type...
Oil
Bath

Dry
Type

FUEL
TANK:
Capacity
16 gal. [60,57 ltr.]
16 gal. [60,57 ltr.]
Between frame
rails,
rear
of vehicle Between frame
rails,
rear
of vehicle

FUEL
PUMP:
Make.
Carter

A.C.

Model.
. 4574-S

6440515

Type
Diaphragm,
serviceable unit
Disposable unit

FUEL
FILTER:
Left
side of engine, plus tank unit
Left
side of engine, plus tank unit 136

'Jeep*
UNIVERSAL SERIES SERVICE
MANUAL

F EXHAUST SYSTEM

Contents

SUBJECT
PAR.

GENERAL
.F-l Dauntless V-6 Engine Exhaust System....
F-3

Hurricane
F4 Engine Exhaust System....
F-2

MAINTENANCE
REQUIREMENTS
F-4

EXHAUST SYSTEM SERVICING
F-5
SUBJECT
PAR.

Exhaust
Manifold Installation. .F-6
Exhaust
Pipe(s) Replacement F-8

Heat
Control Valve Replacement F-7

Muffler
Replacement F-9
Tail
Pipe Replacement F-10

EXHAUST SYSTEM SPECIFICATIONS.
.
F-11

F-L
GENERAL
The
major components of the exhaust system (Figs.
F-l,
F-2 and F-3) are the exhaust manifold(s), ex­
haust pipe(s), muffler and tail pipe. Differences in
the exhaust system occur depending on whether the vehicle is equipped with the Hurricane F4 or
Dauntless V-6 engine.

Note:
For service information on exhaust emission
control systems, refer to Section Fl and F2 of this

manual.
F-2. Hurricane
F4 Engine Exhaust System

On
the Hurricane F4 engine, the exhaust and in­
take manifolds are separate units. The intake mani­
fold is cast as an integral part of the cylinder head

and
is completely water jacketed.
This
construction

transfers
heat from the cooling system to the in­
take riser and assists in vaporizing the fuel when
the
engine
is cold.

With
this construction, there is no heat control
valve on the
engine
and the only function of the exhaust manifold is to gather and direct the exhaust
FIG.
F-l—HURRICANE F4 ENGINE EXHAUST
SYSTEM
—
EARLY
MODEL
1—
Exhaust
Pipe
2—
Clamp

3—
Exhaust
Pipe Extension
4—
Clamp

5— Tail
Pipe 6—
Muffler
7—
Clamp

8—
Support
Strap

9—Bolt

10—Support
Strap
11—Bracket

12—
Insulator

13—
Bracket

14—
Nut
and
Lockwasher
15—
Washer

16—Bolt

17—
Gasket

18—
Bolt
19— Nut
137

F

EXHAUST
SYSTEM
12844

FIG.
F-2—DAUNTLESS
V-6
ENGINE
EXHAUST
SYSTEM
—
EARLY
MODEL
1—
Right
Exhaust
Pipe
19—Lockwasher

2—Tall
Pipe 20—Bolt

3—
Bolt
21—Bracket

4—
Bolt
22—Insulator

5—
Muffler
23—Nut 6—
Exhaust
Pipe
Extension
24—Bolt
7—
Crossover
Exhaust
Pipe
25—Clamp

8—
Bracket
26—U-Bolt 9—
Lockwasher
27—Saddle

10—
Nut
28—U-Bolt
11—
Saddle
29—Saddle

12—
Washer
30—Insulator

13—Bolt
31—U-Bolt
14—
Bracket
32—Nut

15—
Reinforcement
3
3—Lockwasher

16—
Nut
34—U-Bolt

17—
Lockwasher
35—Saddle

18—
Nut

gases
into the exhaust pipe.

When
assembling the manifold, to the cylinder
block
(Fig.
F-4)
new gaskets should be installed
and
the nuts drawn up evenly until they are tight
to avoid leakage. Torque manifold nuts to 29-35 lb-ft [4,0 a 4,84 kg-m.].

F-3.
Dauntless
¥-6
Engine
Exhaust System

Each
of two cylinder banks of a Dauntless V-6 engine has an exhaust manifold. On late production engines the right exhaust manifold is equipped

with
a heat collector manifold which supplies heated air to the air cleaner. See Fig. F-5.
Each
cylinder
exhausts through its own individual port
into a branch of its exhaust manifold. These
branches
conduct exhaust
gases
into the main mani­
fold branch which connects the exhaust pipe to
the muffler. A thermally-actuated heat control valve is located at the
rear
of the right exhaust

manifold.
This
valve has a bimetal thermostatic
spring
which holds it closed when the engine is

cold.

In
closed position, the valve deflects exhaust
gases

upward
through a passage in the intake manifold to the left exhaust manifold.
This
aids in vaporizing

fuel,
speeds
engine warm-up, and reduces oil
dilution.

Since
the valve plate is offset-mounted, the valve

will
be forced partially open at higher engine speed
and
load.
This
prevents excessive back pressure. 138