Pontiac firebird 1968 - V-8 Engine-Service

6-38
1968 PONTIAC SERVICE MANUAL
V-8 ENGINE—SERVICE
CONTENTS OF THIS SECTION
SUBJECT PAGE
General Description . 6-38
Periodic Service 6-39
Service Operations on Car. 6-40
Engine Insulators—Remove and Replace ... 6-40
Drive Belts—Adjust .............. 6-43
Engine—Remove and Install 6-43
Manifold— Valve Trains— Cylinder Heads
Right Side Exhaust Manifold or Gasket-
Remove and Replace ........... 6-43
Left Side Exhaust Manifold or Gasket-
Remove and Replace 6-44
Intake Manifold or Gasket-
Remove and Replace . 6-44
Push Rod Cover or Gasket-
Remove and Replace 6-45
Valve Springs, Shield or Seal-
Remove and Replace ........... 6-45
Push Rod and Valve Lifter-
Remove and Replace . . . . 6-46
Cylinder Head or Gasket-
Remove and Replace ........... 6-49
Rocker Arm Studs—Remove and Replace . . 6-50
Cylinder Head and Valve— Recondition . . . 6-51
Valves and Seats— Recondition 6-52
SUBJECT PAGE
Harmonic Balancer— Timing Chain Cover
and Gasket—Timing Chain and Sprockets-
Oil Seal— Fuel Pump Eccentric 6-53
Camshaft and/or Camshaft Bearing-
Remove and Replace ........... 6-56
Oil Pan and/or Oil Pan Gasket-
Remove and Replace 6-58
Oil Pump—Recondition 6-60
Rear Main Bearing Oil Seal-
Remove and Replace . 6-61
Main Bearings— Remove and Replace .... 6-62
Connecting Rod Bearings-
Remove and Replace 6-63
Connect Rod and Piston Assembly-
Remove and Replace 6-64
Connecting Rod and Piston Assembly-
Recondition ......... 6-64
Piston Rings—Replace 6-67
Crankshaft— Remove and Replace 6-69
Fitted Block Assembly — Replace 6-71
Specifications .................. 6-76
Wrench Torque Specifications. ........ 6-76
Special Tools 6-80
GENERAL DESCRIPTION
V-8 engine is standard equipment on Pontiac and
G.T.O. models, and optional on all Firebird and
Tempest models. The optional Tempest V-8 has
displacement of 350 cubic inches with 3 7/8" bore
and 3 3/4" stroke. This engine is available in two
compression ratios: 9.2:1 and 10.5:1.
gines have four attaching bolts in the three center
main bearing caps as compared to two bolts per cap
in other engines. Fig. 6-68 shows the four-bolt cap
installation.
CYLINDER HEAD
Two types of cylinder heads differing in valve
A 400 cubic inch V-8 engine is standard on Pontiac
and G
a
T.O.
f
s. This engine has 4.120" bore and
3 3/4" stroke and is available in three compression
ratios: 8.6:1, 10.5:1 and 10.75:1. *
Both the 350 and 400 cubic inch V-8 engines are
optional on the Firebird model.
A 428 cubic inch V-8 engine is optional on Pontiac
models. This engine has 4.120" bore and 4" stroke.
The compression ratio is 10.5:1 with a 428 high out-
put engine at 10.75:1.
CYLINDER BLOCK
The cylinder block used for 400 and 428 engines
has three core hole plugs on each side and is more
rigid with improved machining. Cylinder blocks for
the 350, 400 and 428 engines are shown in Figs. 6-67
and 6-68.
t.
K
9? ' * x
£fc -f
428 cubic inch and 400 cubic inch Ram-Air en-
Fig. 6-67 Cylinder Block-350 and 400 Engine