check engine light CHEVROLET CAMARO 1967 1.G Chassis User Guide

ENGINE 6-37

Fig.
27V—Removing Camshaft

4.
Set dial indicator on zero, then rotate the damper

slowly, or attach an auxiliary starter switch and

"bump" the engine over, until the push rod is in the

fully raised position.

CAUTION: The primary distributor lead must

be disconnected from the negative post on the

coil and the ignition switch must be in the on

position. Failure to do this will result in a dam-

aged grounding circuit in the ignition switch.

5.
Compare the total lift recorded from the dial indica-

tor with specifications.

6. Continue to rotate the crankshaft until the indicator

reads zero. This will be a check on the accuracy of

the original indicator reading.

7.
If camshaft readings for all lobes are within specifi-

cations, remove dial indicator assembly.

8. Install and adjust valve mechanism as outlined.

Removal

1.
Remove valve lifters as outlined.

2.
Remove crankshaft front cover as outlined.

3.
Remove grille as outlined in Section 13.

4.
Remove fuel pump push rod as outlined * in Sec-

tion 6M.

5.
Complete camshaft removal as follows:

CAUTION: All camshaft journals are the same

diameter and care must be used in removing

camshaft to avoid damage to bearings.

Remove camshaft sprocket to camshaft bolts then

remove sprocket and timing chain together. Sprocket

is a light fit on camshaft. If sprocket does not come

off easily a light blow on the lower edge of the

sprocket (with a plastic mallet) should dislodge the

sprocket.

Install two 5/16" - 18 x 4" bolts in camshaft bolt

holes then remove camshaft (fig. 27V).

Installation

NOTE: Whenever a new camshaft is installed
CONVERTER

BOLT AREA -

DEPRESSED

SYNCHROMESH
RING

GEAR

TRANS.,

AUTOMATIC

Fig.
28V - Flywheel Installation (Typical)

coat camshaft lobes with Molykote or its

equivalent.

1.
Lubricate camshaft journals with engine oil and in-

stall camshaft.

2.
Install timing chain on camshaft sprocket. Hold the

sprocket vertical with the chain hanging down, and

orient to align marks on camshaft and crankshaft

sprockets. Refer to Figure 20V.

3.
Align dowel in camshaft with dowel in hole in cam-

shaft sprocket then install sprocket on camshaft.

Refer to Figure 25V.

4.
Draw the camshaft sprocket onto camshaft using the

mounting bolts. Torque to specifications.

5.
Lubricate timing chain with engine oil.

6. Install fuel pump push rod as outlined in Section 6M.

7.
Install grille as outlined in Section 13.

8. Install crankcase front cover as outlined.

9. Install valve lifters as outlined.

FLYWHEEL

Removal

With transmission and/or clutch housing and clutch

removed from engine, remove the flywheel.

Installation

1.
Clean the mating surfaces of flywheel and crankshaft

to make certain there are no burrs.

2.
Install flywheel on crankshaft and position to align

dowel hole of crankshaft flange and flywheel (fig.

28V).

NOTE: On Automatic Transmission equipped

engines, the flywheel must be installed with the

flange collar to transmission side (fig. 33V).

ENGINE MOUNTS

Engine mounts (fig. 34V) are the nonr adjustable type

and seldom require service. Broken or deteriorated

mounts should be replaced immediately, because of the

added strain placed on other mounts and drive line

components.

Front Mount Replacement

1.
Remove nut, washer and engine mount through-bolt.

2.
Raise engine to release weight from mount.

3.
Remove mount from engine.

CHEVROLET CHASSIS SERVICE MANUAL

SECTION 6M

ENGINE FUEL

CONTENTS OF THIS SECTION

Page

Carburetors 6M-1 Fuel Pumps .

Air Cleaners 6M-7 Special Tools
Page

6M-10

6M-12

CARBURETORS

INDEX

Page

General Description 6M-1

Service Procedures 6M-1

Preliminary Checks 6M-1

Idle Speed and Mixture Adjustment ........... 6M-1

Fast Idle Adjustment .................. 6M-3

Choke Adjustment 6M-3

Float Adjustment 6M-4
Page

Additional Adjustments 6M-4

Removal 6M-4

Test Before Installation 6M-5

Installation 6M-5

Fuel Filter Maintenance 6M-5

Choke Coil Replacement 6M-5

Throttle Linkage Adjustment . . 6M-6

GENERAL DESCRIPTION

Various carburetors (fig. lc) are used with Chevrolet,

Chevelle, Chevy II, Camaro and Corvette passenger

vehicles. These carburetors are designed to meet the

particular requirements of engines, transmissions and

vehicles, therefore carburetors that look alike are not

always interchangeable. (Refer to carburetor part num-

ber and/or specifications.)

Because many service procedures for the various

carburetors are similar, typical illustrations and pro-

cedures are used except where specific illustrations or
procedures are necessary to clarify the operation.

This section covers removal, installation and adjust-

ments (on engine) of carburetors. Also covered in this

section are maintenance procedures for choke coils,

throttle linkage and fuel filters. For carburetor .over-

haul procedures and additional adjustments (bench), re-

fer to Section 6M of the Overhaul Manual under the

carburetor being serviced.

Specifications for carburetors are located in the back

of this manual.

SERVICE PROCEDURES

Preliminary Checks

1.
Thoroughly warm-up engine. If the engine is cold,

allow to run for at least 15 minutes.

2.
Inspect torque of carburetor to intake manifold bolts

and intake manifold to cylinder head bolts to exclude

the possibility of air leaks.

3.
Inspect manifold heat control valve (if used) for free-

dom of action and correct spring tension.

Idle Speed and Mixture Adjustment (Except Air Injection

Reactor System)

NOTE:
This adjustment should be performed

with engine at operating temperature and park-

ing brake applied.

1.
Remove Air Cleaner.

2.
Connect tachometer and vacuum gauge to engine, then

set hand brake and shift transmission into neutral.

3.
As a preliminary adjustment, turn idle mixture

screws lightly to seat and back out 1-1/2 turns.

CAUTION: Do not turn idle mixture screw

tightly against seat or damage may result.

4.
With engine running (choke wide open) adjust idle
speed screw to specified idle speed, (automatic

transmission in drive, synchronized transmission in

neutral).

5. Adjust idle mixture screw to obtain highest steady

vacuum at specified idle speed.

NOTE:
On air conditioned vehicles, turn air

conditioning to the "on" position and hold the

hot idle compensator valve closed while adjust-

ing idle speed and idle mixture screws.

NOTE:
On Rochester BV carburetors the idle

mixture screw should be turned out 1/4 turn

from the "lean roll" position. The definition

of "lean roll" point is a 20 to 30 rpm drop

in engine speed obtained by leaning the idle

mixture.

6. Repeat Steps 4 and5 as needed for final adjustment.

NOTE:
If necessary, final adjustment of the \

carburetor may be made with the air cleaner

installed.

7. Turn engine off, remove gauges and install air

clearer.

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE FUEL 6M-3

Idle Speed and Mixture Adjustment (With Air Injection

Reactor System)

The following is the recommended procedure for Air

Injection Reactor System equipped engines.

NOTE: This adjustment should be performed

with engine at operating temperature and parking

brake applied.

1.
Remove air cleaner.

2.
Connect tachometer to engine, then set hand brake

and shift transmission into neutral.

3.
As a preliminary adjustment, turn idle mixture

screws lightly to seat and back out 3 turns.

CAUTION: Do not turn idle mixture screw

tightly against seat or damage may result."

4.
With engine running (choke wide open) adjust idle

speed screw to specified idle speed. (Automatic

transmission in dirve, synchronized transmission in

neutral).

5.
Adjust idle mixture screw (turn in) to "lean roll"

position; then turn screw out 1/4 turn (1/4 turn

rich from "lean roll"). The definition of "lean

roll" point is a 20 to 30 rpm drop in engine speed,

obtained by leaning the idle mixture.

NOTE: On air conditioned vehicles, turn air

conditioning "OFF" on in-line, 283, 327, and'

350 cu. in. engines, and turned "ON" and hot

idle compensator held closed on 396 and 427 cu.

in. engines.

6. Repeat Steps 4 and 5 as needed for final adjustment.

NOTE: If necessary, final adjustment of the
carburetor may be made with air cleaner

installed.

7.
Shut down the engine, remove gauges and install air

cleaner. *

Fast Idle Adjustment

Rochester
4MV and Holley

With fast idle lever on high step of cam and choke valve

open (engine warm) set fast idle to give specified engine

rpm. Adjust sejrew on Rochester 4MV and bend fast

idle lever *pn Holley. .

Choke Adjustment

With Remote Choke (Fig. 2c)

1.
Remove air cleaner and check to see that choke

valve and rod move freely.

2.
Disconnect choke rod at choke lever.

3.
Check choke adjustment as follows:

On all except 275 and 300 h.p. 327 cu. in. engines,

hold choke valve closed and pull.rod up against stop.

The top of choke rod end should be 1/2-1 rod diame-

ter above top of hole in choke valve lever.

On 275 and 300 h.p. 327 cu. in. engines, hold choke

valve closed and push rod down against stop on ther-

mostat bracket. The top of the choke rod should be

1/2-1 rod diameter below the top of the hole in the

choke lever.

4.
If necessary, adjust rod length by bending rod at

offset bend. (Bend must be such that rod enters

choke lever hole freely and squarely).

5.
Connect rod at choke lever and install air cleaner.

With Manual Choke (Carter YF)

1.
Remove air cleaner.

CHOKE VALVE

COMPLETELY

CLOSED

PULL UPWARD ON

ROD TO END OF

TRAVEL

BEND ROD

TO ADJUST
ROD IN BOTTOM

OF SLOT

BOTTOM OF

ROD SHOULD

BE EVEN WITH

TOP OF

HOLE
CHOKE VALVE

CLOSED

BOTTOM OF

ROD SHOULD

BE EVEN WITH

TOP OF HOLE

TOP OF ROD

SHOULD BE EVEN

WITH BOTTOM

OF HOLE (CHOKE

CLOSED)

BEND ROD TO

ADJUST

PULL DOWNWARD'

ON ROD TO CON-

TACT STOP

L6 (TYPICAL)

[

V8 327-275 HP

V8 350-295 HP
BEND ROD

TO ADJUST

PULL UPWARD ON

ROD TO CONTACT

STOP ON BRACKET

ALL V8 (EXCEPT 327-275 HP

AND 350-295 HP)

Fig.
2C—Remote Choke Adjustment

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE FUEL 6M-4

Fig.
3C-Fuel Level Sight Plug

2.
Push hand choke knob in to within 1/8" of instru-

ment panel.

3.
Loosen choke cable clamp at carburetor bracket and

adjust cable through the clip until the choke valve

is wide open.

4.
Tighten cable clamp at carburetor bracket and check

operation of choke valve to ensure full closed and

wide open positions.

5. Install air cleaner.

Float Adjustment

Ho/fey (Model 4150
Center
Inlet & Model 2300)

1.
Remove air cleaner then remove the fuel level sight

plugs (Fig. 3c)

2.
With parking brake on, and transmission in neutral,

start the engine and allow it to idle.

3.
With the car on a level surface, the fuel level should

be on a level with the threads at the bottom of the

sight plug port (plus or minus 1/32 inch).

NOTE:
No float drop adjustment is required

on this carburetor.

4.
If necessary to adjust (either or both bowls), loosen

inlet needle lock screw and turn the adjusting nut

clockwise to lower or counter-clockwise to raise

fuel level, then tighten lock screw.

NOTE:
1/6 turn of adjusting nut equals ap-

proximately 1/16" fuel level change.

5. Allow a minute for fuel level to stabilize then re-

check the level at sight plug.

6. Readjust, if necessary, until proper level is obtained,

then install sight plug and air cleaner.

NOTE:
To assure proper secondary float level

setting it is advisable to accelerate primary

throttles slightly and hand operate secondary
throttle. This assures a stabilized secondary

fuel level.

Additional Adjustments

The following adjustments may be made without re-

moving the carburetor from the engine. For procedure

refer to Section 6M of the Overhaul Manual under the

carburetor being serviced.

Rochester BV

• Float

• Idle Vent

• Choke Rod (Fast Idle)

• Choke Vacuum Break

• Choke Unloader

Rochester 2GV

• Float

• Accelerator Pump

• Idle Vent

• Choke Rod (Fast Idle)

• Choke Vacuum Break

• Choke Unloader

• Secondary Throttle Opening

• Secondary Throttle Lockout

Rochester 4MV

• Float

• Accelerator Pumj)

• Idle Vent

• Air Valve

• Choke Rod

• Choke Vacuum Break

• Choke Unloader

• Air Valve Lockout

• Secondary Opening

• Secondary Lockout

Carter YF

• Float

• Idle Vent

• Choke Rod (Fast Idle)

• Choke Vacuum Break

• Choke Unloader

Holley 4160 and 4150
(Except End
Inlet)

• Float

• Air Vent Valve

• Accelerator Pump

• Choke Vacuum Break

• Choke Unloader

Holley 2300 and 4150
(End
Inlet)

• Air Vent Valve (except 2300)

• Accelerator Pump

• Choke Vacuum Break

• Choke Unloader

Removal

Flooding, stumble on acceleration and other perform-

mance complaints are, in many instances, caused by the

presence of dirt, water, or other foreign matter in the

carburetor. To aid in diagnosing the cause of the com-

plaint, the carburetor should be carefully removed from

the engine without draining the fuel from the bowl.

The contents of the fuel bowl may then be examined for

contamination as the carburetor is disassembled.

1.
Remove air cleaner and gasket.

2.
Disconnect fuel and vacuum lines from carburetor.

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE FUEL 6M-8

^T^l^^/'-vN

COVER
BOTTOM

Fig. 1A—Polyurethane Element Air Cleaner
OIL RESISTANCE

SEAL

BOTTOM
BONDED PAPER

ELEMENT

COVER

Fig. 2A—Paper Element Air Cleaner

SERVICE
PROCEDURES

POLYURETHANE ELEMENT

Maintenance

1.
Remove cover wing nut, cover and filter element.

2.
Visibly check the element for tears or rips and re-

place if necessary.

3.
Clean all accumulated dirt and grime from air

cleaner bottom and cover. Discard air horn to air

cleaner gasket.

4.
/Remove support screen from element and wash

element in kerosene or mineral spirits; then squeeze

out excess solvent (fig. 3A).

NOTE: Never use a hot degreaser or any sol-

vent containing acetone or similar solvent*

5.
Dip element into light engine oil and squeeze out

excess oil.
NOTE: Never shake, swing or wring the ele-

me.nt to remove excess oil or solvent as this

may tear the polyurethane material. Instead,

"squeeze" the excess from the element.

6. Install element'on screen support (fig. 4A).

7.
Using a new gasket, replace air cleaner body over

carburetor air horn.

8. Replace the element in the air cleaner. Care must

be taken that the lower lip of the element is properly

placed in the assembly and that the filter material

is not folded or creased in any manner that would

cause an imperfect seal. Take the same precautions

when replacing the cover that the upper lip of the

element is in proper position.

9.<•
Replace cover and wing nut.

OIL BATH

Maintenance

L Remove air cleaner assembly.

2.
Remove cover and filter element assembly.

Empty oil out of

accumulated dirt.
cleaner and clean out all oil and

Fig. 3A—Cleaning Polyurethane Element

Fig.
4A—Polyurethane Support

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE FUEL 6M-9

4.
Wash body with cleaning solvent and wip dry.

5. Wash filter element by sloshing up and down in

cleaning solvent.

6. Dry filter unit with an air hose or let stand until

dry.

7. Fill body of cleaner to full mark with SAE 50 engine

oil. If expected temperatures are to be consistently

below freezing, use SAE 20 engine oil.

8. Assemble filter and cover assembly to body of

cleaner.

9. Install cleaner, making sure it fits tight and is set

down securely. \

OIL
WETTED
PAPER
ELEMENT

Replacement

1.
Remove wing nut, washer and cover.

2.
Remove paper element and discard.

3.
Remove bottom section of air cleaner and gasket

on air horn of carburetor. Discard air horn gasket.

4.
Clean bottom section of air cleaner and cover pieces

thoroughly, to remove dust and grime.

NOTE:
Check bottom section of air cleaner

seal for tears or cracks.

5. Install a new gasket on carburetor air horn and set

bottom section of air cleaner on carburetor.

6. Install new paper element on bottom section of air

cleaner with either end up.

NOTE:
Plastisol seal is the same material on

both ends.

7. Install cover, washer and wing nut.

Testing (Fig. 5A)

Tool J-7825, is designed to check paper element air

cleaners to determine whether the element has ma-

terially decreased in efficiency arid should be replaced

or has only slightly increased air restriction and is

suitable for further service. In combination with a

tachometer, this instrument will quickly and accurately

determine the air cleaner element condition.

VENT HOLE

TOWARD DASH
NOTE:
t Before testing, inspect for holes or

breaks in the element, as these defects re-

quire immediate replacement. If no holes or

breaks exist, proceed as follows:

1.
Remove all hoses and plug all openings except air

cleaner inlet.

2.
Install air cleaner, using Tool J-7825 in place of the

wing nut. Screw Tool J-7825 onto the stud until it

seals tightly against the air cleaner cover. Rotate

the entire tool so that the scale can be read from

the left side of the car. Be sure the vent hole is

toward the dash.

3.
Connect a tachometer and place it so that it may be

read simultaneously with Tool J-7825.

4.
Zero oil level in the inner tube by pulling inner tube

upward until the rubber seal is above the vent hole,

then raise or lower as' required until the inner tube

oil level is exactly to the "0" mark.

5. Start engine. If engine is cold, allow to run for 2 to

3 minutes. The automatic choke must be fully open.

6. Accelerate the engine slowly until the inner tube oil

level of Tool J-7825 just reaches the 1/4 mark.

Allow engine speed to stabilize and note tachometer

(rpm) reading. Decelerate engine.

7. If the tachometer reading is at or below the follow-

ing, the oil wetted paper air cleaner element is re-

stricted beyond the allowable limit and should be

replaced. If testing indicates that the element

restriction is satisfactory at 12,000 miles, the ele-

ment need not be replaced but should be retested

every 6,000 miles thereafter until replaced.

Engine

Displacement

283 cu.
in.

327 cu.
in.

350 cu. in.

396 cu.
in.

427 cu.
in.
Horsepower

195

210

275

300

325

350

295

325

350

385

390

425
Minimum

Allowable

RPM

2300

2100

210Q

2600

2600

1550

1950

1850

1850

2140

Fig.
5A—Testing Air Cleaner
8. Remove tachometer and Tool J-7825 from vehicle

and push down inner tube until seal is below vent

hole to prevent oil loss.

Tool J-7825

FiHing
Tool

Tool J-7825 is shipped dry and must be filled with the

red gauge oil (specific gravity .826) provided.

Pull the knurled inner tube completely out of the gauge

and add oil to the reservoir until the oil level is between

CHEVROLET CHASSIS SERVICE /MANUAL

ENGINE-EIECTRICAI 6Y-3

PERIODIC SERVICING

Since the Battery is a perishable item which requires

periodic servicing, a good maintenance program will

insure the longest possible Battery life.

COMMON CAUSES OF FAILURE

If the Battery tests good but fails to perform satis-

factorily in service for no apparent reason, the following

are some of the more important factors that may point to

the cause of the trouble.

1.
Vehicle accessories inadvertently left on overnight to

cause a discharged condition.

2.
Slow speed driving of short duration, to cause an

3.
undercharged condition.

A vehicle

capacity.
electrical load exceeding the generator

4.
Defect in the charging system such as high resist-

ance, slipping fan belt, faulty generator or voltage

regulator.

5. Battery abuse, including failure to keep the Battery

top clean, cable clamps and posts clean and tight,

and improper addition of water to the cells.

LEVEL INDICATOR

The Battery features an electrolyte level indicator,

which is a specially designed vent plug with a transparent

rod extending through the center (fig. 5b). When the elec-

trolyte is at the proper level, the lower tip of the rod is

immersed, and the exposed top of the rod will appear

very dark; when the level falls below the tip of the rod,

the top will glow. ,

The Indicator reveals at a glance if water is needed,

without the necessity of removing the vent plugs (fig. 6b).

The Level Indicator is used in only one cell (second

cell cap from positive Battery post) because when the

electrolyte level is low in one cell, it is normally low in

all cells. Thus when the Indicator shows water is needed,

check the level in all six cells.

An alternate method of checking the electrolyte level is

to remove the vent plug and visually observe the electro-

lyte level in the vent well. The bottom of the vent well

features a split vent which will cause the surface of the

electrolyte to appear distorted when it makes contact.

The electrolyte level is. correct when the distortion first

appears at the bottom of the split vent (fig. 4b).

ELECTROLYTE LEVEL

The electrolyte level in the Battery should be checked

regularly. In hot weather, particularly during trip driv-

ing, checking should be more frequent because of more

rapid loss of water. If the electrolyte level is found to be

low, then colorless, odorless, drinking water should be

added to each cell until the liquid level rises to the split

vent located in the bottom of the vent well. DO NOT

OVERFILL because this will cause loss of electrolyte

resulting in poor performance, short life, and excessive

corrosion.

CAUTION: During service only water should be

added to the Battery, not electrolyte.

The liquid level in the cells should never be allowed to

drop below the top of the plates, as the portion of the
INDICATOR

ELECTROLYTE LEVEL

CORRECT

Fig.
5b—Cut-Away View Showing Electrolyte at Proper Level

with Indicator Having Dark Appearance

plates exposed to air may be permanently damaged with a

resulting loss in performance.

WATER USAGE

Excessive usage of water indicates the Battery is being

overcharged. The most common causes of overcharge

are high Battery operating temperatures, too high a volt-

age regulator setting, poor regulator ground wire con-

nection. Normal Battery water usage is approximately

one to two ounces per month per battery.

INDICATOR

Fig.
6b—Cut-Away View Showing Electrolyte at Low Level

with Indicator Having Light Appearance

CHASSIS SBtVKZ MANUAL

ENGINE-ELECTRICAL
6Y-4

CLEANING

The external condition of the Battery should be checked

periodically for damage or for the presence of dirt and

corrosion. The top of the Battery should be kept clean.

An accumulation of acid film and dirt may permit current

to flow between the terminals, which will slowly dis-

charge the Battery. For best results when cleaning the

top of Batteries, wash first with a diluted ammonia or a

soda solution to neutralize any acid present; then flush

with clean water. Care must be taken to keep vent plugs

tight, so that the neutralizing solution does not enter the

cells.

CABLES

To insure good electrical contact, the cables should be

clean and tight on the Energizer posts. If the posts or

cable terminals are corroded, the cables should be dis-

connected and the terminals and clamps cleaned sepa-

rately with a soda solution and a wire brush. After

cleaning and installing clamps, apply a thin coating of

petroleum jelly on the cable clamps to retard corrosion.

CARRIER
AND
HOLD-DOWN

The Battery carrier and hold-down should be clean and

free from corrosion before installing the Battery. The

carrier should be in a sound mechanical condition so that

it will support the Battery securely and keep it level.

To prevent the Battery from shaking in its carrier,

the hold-down bolts should be tight (60-80 in. lbs.). How-

ever, the bolts should not be tightened to the point where

the Battery case or cover will be placed under a severe

strain.

BATTERY SAFETY PRECAUTIONS

When Batteries are being charged, an explosive gas

mixture forms in each cell. Part of this gas escapes

through the holes in the vent plugs and may form an

explosive atmosphere around the Battery itself if ventila-

tion is poor. This explosive gas may remain in or around

the Battery for several hours after it has been charged.

Sparks or flames can ignite this gas causing an internal

explosion which may shatter the Battery.

The following precautions should be observed to pre-

vent an explosion:

1.
Do not smoke near Batteries being charged or which

have been very recently charged.

2.
Do not break live circuits at the terminals- of Batr

teries because a spark usually occurs at the point

where a live circuit is broken. Care must always be

taken when connecting or disconnecting booster leads

or cable clamps on fast chargers. Poor connections

are a common cause of electrical arcs which cause

BATTERY CHARGING PROCEDURES

There are three methods of recharging Batteries.

They differ basically in the length of time the Battery is

charged and the rate at which charging current is sup-

plied. One is the Slow Charge method, the second is the

Fast Charge method, and the third is the Emergency

Boost Charge method.

Before recharging a Battery by any method, the elec-

trolyte level must be checked and adjusted if necessary.
SLOW CHARGING

The Slow Charge method supplies the Battery with a

relatively low current flow for a relatively long period of

time. This is the only method that will bring the Battery

to a full state of charge.

The Slow Charge method consists of charging at

approximately a 4 ampere rate for 24 hours or more if

necessary to bring the Battery to full charge. A fully

charged condition is reached when the cells are gassing

freely and three corrected specific gravity readings

taken at hourly intervals show no increase.

FAST CHARGING

The Fast Charge method supplies current to the Bat-

tery at a 40 to 50 ampere rate for a 1 1/2 hour period of

time. If the electrolyte temperature reaches 125°F before

the 1 1/2 hour period is completed, the Battery must be

taken off charge temporarily, or the charging rate

reduced to avoid damage to the Battery.

Although a Battery cannot be brought to a fully charged

condition during Fast Charge, it can be substantially

recharged or "boosted". In order to bring the Battery to

a fully charged condition, the charging cycle must be

finished by the Slow Charge method.

EMERGENCY BOOST CHARGING

In cases where the Battery is not sufficiently charged

to crank the engine, an emergency boost charge may be

applied as a temporary expedient in order to crank the

engine. The Emergency Boost Charge method consists of

charging at a 40 to 50 ampere rate for a period of one-

half hour.

It should be particularly noted that the Emergency

Boost Charge will not necessarily restore the Battery to

a useful state of. charge for continued service. After an

emergency boost charge, failure to charge the Battery

further, either by a long uninterrupted driving period or

by the Fast Charge or Slow Charge method, may result

in failure to crank the engine the next time cranking is

attempted. A Battery should never be condemned on the

basis of failure to crank the engine after an emergency

boost charge. Although an emergency boost charge may

put enough energy into the Battery to crank the engine

once, further charging usually is necessary in order to

create a sufficient reserve to crank a second and third

time.

12
VOLT BATTERY SUGGESTED

CHARGING RATES

(100 Amp/hr or Less Capacity)

TYPE OF

CHARGE

Boost Charge for

Light Load Test

Slow Charge

Fast Charge

Quick Boost .

Dry Charge

Warm-up Boost
LENGTH

OF TIME

20 Minutes

24 Hours

1-1/2 Hours

30 Minutes

10 Minutes
CHARGING

RATE

50 Amps

4 Amps

40-50 Amps

40-50 Amps

15 Amps

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE-ELECTRICAL 6Y-7

CHARGING SYSTEM

INDEX

Page

General Description . 6Y-7

Maintenance and Adjustments 6Y-9

Static Checks . 6Y-10

System Condition Check and Voltage

•Regular Adjustment. 6Y-10

General Output 6Y-11

Generator Diode and Field Test 6Y-12

Indicator Lamp-Initial Field Excitation

Circuit Tests . 6Y-12
Page

Field Circuit Resistance Wire Tests 6Y-13

Field Relay Test and Adjustment 6Y-14

Other Harness Checks 6Y-14

Service Operations 6Y-14

Generator 6Y-14

Removal and Installation 6Y-14

Pulley Replacement. 6Y-14

Brush Replacement (6" Delcotron). 6Y-15

Double Contact Regulator . . . . . . 6Y-16

GENERAL DESCRIPTION

The charging system includes the battery, generator,

regulator, telltale light, and necessary wiring to connect

these components. The Delcotron is offered as standard

equipment, although there are various capacities avail-

able on all models.

The Delcotron continuous output A.C. generator (fig.

lc) consists of two major parts, a stator and a rotor. The

stator is composed of a large number of windings as-

sembled on the inside of a laminated core that is attached

to the generator frame. The rotor revolves within the

stator on bearings located in each end frame. Two

brushes are required to carry current through the two

slip rings to the field coils wound concentric with the

shaft of the rotor. Six rectifier diodes are mounted in the

slip ring end frame and are joined to the stator windings

at three internally located terminals.

Diodes are mounted in heat sinks to provide adequate

heat dissipation. The six diodes replace the separately
mounted rectifier as used in other types of application.

The diodes change the Delcotron A.C. current to D.C.

current.

Two regulators (fig. 2c) are available on the 1967 vehi-

cles,
a double contact two unit type and a transistor

regulator. The function of these regulators in the charg-

ing system is to limit the generator voltage to a pre-set

value by controlling the generator field current. Both

regulators have an internal field relay unit. The relay

unit allows the telltale lamp to light (as a bulb check)

with the ignition key on and engine not running. When the

engine is started and the generator begins to charge, the

indicator light goes out indicating that the system is op-

erating normally.

The double contact regulator, when used with the

special 63 amp air conditioning model generator (4 ohm

field coil) uses a field discharge diode internally in the

field circuit (figs. 3c and 4c). The added diode adapts the

BRUSH AND

TERMINAL

ASSEMBLY

SLIP RINGS
SLIP RING

END FRAME

_\

THRU

BOLT
DRIVE END

FRAME

BEARING

BEARING

DIODES

ROTOR

5.5" SERIES ID DELCOTRON
STATOR

ASSEMBLY
GREASE

RESERVOIR

BRUSH

FAN ASSEMBLY

6.2" SERIES 2D TYPE 150 DELCOTRON

Fig.
lc—Delcotron Cross-section View

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE-ELECTRICAL 6Y-9

63 AMP 1

MODELS ONLY'
BATTERY FUSIBLE

LINK
HORN

FUSIBLE LINK'
TRANSISTOR
FUSIBLE LINK'

Fig.
4c— Circuitry - Voltage Regulator Assemblies (Corvette)

Engine compartment wiring harness incorporates sev-

eral fusible links. Each link is identified with its gage

size. A fusible link is a length of special wire (normally

four wire gages smaller than the circuit it is protecting)

used in wiring circuits that are not normally fused, such

as the ignition circuit. The same size wire with a hypalon

insulation must be used when replacing a fusible link.

The links are:

1.
The pigtail lead at the battery positive cable (except

Corvette) is a 14 gage, brown fusible link protecting

the 10 gage battery charging circuit. This wire is an

integral part of the battery cable assembly and serv-

icing requires replacing the complete battery cable

assembly. On Corvette models this link is installed

as a molded splice at the solenoid "Bat" terminal

and servicing requires splicing in a new link.

2.
A 16 gage black fusible link is located at the horn
4.
relay to protect all unfused wiring of 12 gage or

larger. It is installed as a molded splice and serv-

icing requires splicing in a new link.

The generator warning light and field circuitry (16

gage wire) is protected by a fusible link (20 gage

orange wire) used in the "battery feed to voltage

regulator #3 terminal" wire. The link is installed as

a molded splice in the generator and forward lamp

harness and is serviced by splicing in a new 20 gage

wire as required.

The ammeter circuit on all models is protected by

two orange, 20 gage wire fusible links installed as

molded splices in the circuit at the junction block or

the solenoid "Bat" terminal (Corvette only) and at

the horn relay. Each link is serviced by splicing in a

new 20 gage wire as required.

MAINTENANCE AND ADJUSTMENTS

At regular intervals, inspect the terminals for cor-

rosion an4 loose connections, and the wiring for frayed

insulation. Check mounting bolts for tightness. Check the

drive belt for alignment, proper tension and wear. Be-

cause of the higher inertia and load capacity of the rotor

used in A.C. generators, PROPER BELT TENSION is

more critical than on D.C. generators.

Since the Delcotron and its companion regulator are

designed for use on negative polarity systems only, the

following precautions must be observed. Failure to ob-

serve these precautions may result in serious damage to

the charging system.

1.
When installing a battery, always make absolutely

sure the ground polarity of the battery, generator and

regulator is the same.

2.
When connecting a booster battery, make certain to

connect the correct battery terminals together.

3.
When connecting a charger to the battery, connect the

correct charger leads to the battery
%
terminals.

4.
Never operate the generator on an uncontrolled open
TO SOLENOID

BAT ACC RES. WIRE

Fig.
5c—Typical Wiring Diagram Showing Lead Connections

CHEVROLET CHASSIS SERVICE MANUAL