Pontiac firebird 1968 - Specifications

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1968 PONTIAC SERVICE MANUAL
6-CYLINDER ENGINE WRENCH TORQUE -SPECIFICATIONS
NOTE: Torque in lb. ft. unless otherwise shown.
APPLICATION _ TORQUE
Bolt - Main Bearing Cap to Block . . ....... 100
Bolt - Rear Main Bearing Cap to Block .............. ....... . . 100
Bolt - Cylinder Head . . . . . 95
Bolt - Flywheel to Crankshaft . . . . . . . . 60
Nut - Connecting Rod Bearing Cap • . .
0
. ..o • 33
Bolt - Accessory Drive Housing to Block . . ... • . 15
Bolt (& Nut) - Intake and Exhaust Manifold to Head .......... 30
Bolt - Oil Pan to Block . . . . .......... 12
Bolt - Camshaft Thrust Washer . . . . • ...... . . . 40
Bolt - Camshaft to Sprocket . . ....... o 40
Spark Plug to Head . .......................... ......... . 20
Bolt - Rocker Arm Cover to Head .............
0
.............. • • 15
Bolt - Harmonic Balancer . 160
6-CYLINDER ENGINE SPECIFICATIONS
Type. In-Line 6, Overhead Cam
Bore and Stroke .3-7/8 x 3-17/32
Displacement ...... 250 cu. in.
Taxable Horsepower 36.0
HORSEPOWER AMU TORQUE
Compression
Engine Carburetor Ratio Horsepower Torque
250 1-Bbl. 9.0 175 @ 4800 240 @ 2600
250 Q'Jet 10.5 215 § 5200 255 @ 3800
Compression Pressure at Cranking Speed:
1-Bbl. 150-170 PSI @ 155-165 RPM
Q'Jet 185-205 PSI § 155-165 RPM
Firing Order . . . 1-5-3-6-2-4
Engine Number Location Pad Behind Oil Filler Neck
Cylinder Nos.-Front to Rear 1-2-3-4-5-6
Cylinder Block
Material Alloy Cast Iron
Installation Angle . 4° 19'
Cylinder Head
Material . . .................... . Alloy Cast Iron
Combustion Chamber Wedge Type - Fully Machined
Pistons
Material . . * • Tin-Plated Aluminum Alloy
Type . . . o . . o o * * c Cam and Contour Ground - Slipper Skirt
Measurement Taken At . . . . Top of Skirt
Clearance in Cylinder 0022"-.0028"
Piston Rings
Compression Rings Two Cast Iron, Reverse Twist, Taper Face
Material - Upper Channel Moly Filled
- Lower . Lubrite Finish
Oil Ring Three-Piece
Material - Rails (2) . . . . . Chrome Plated Steel
- Expander Stainless Steel