L- and F- Four-Cylinder Engines

General Valve Timing
Engine Block Pistons and Rings
Crankshaft and Flywheel Camshaft
Cylinder Head and Valve Train Oil Pump
Oversize & Undersize Component Code Letter Definition Torque Specifications

TypeIn-line four-cylinder with F- or L-head valve configuration
Displacement134 cu in
Firing Order1-3-4-2
Cylinder numbering(from front-rear1-2-3-4
Bore and Stroke3-1/8 x 4-3/8 in
Oil Pressure
L-head to S/N 4441750psi at 30 mph
L-head to S/N 44417 and on35 psi at 2000 rpm
f-head35 psi at 2000 rpm

Valve Timing
Intake Valve
Opens9 BTC
Closes50 ABC
Opens47 BBC
Closes12 ATC

Engine Block
Cylinder Bore
Diameter3.125 to 3.127 in
Taper Limit0.005 in
Out-of-Round Limit0.005 in
Deck Warpage Limit0.010 in

Pistons and Rings
Piston Diameter(near bottom of skirt)3.1225 to 3.1245 in
Piston-to-Cyliner Bore Clearance0.003 in
Piston Ring Side Clearance
Top Ring0.002 to 0.004 in
2nd Ring0.0015 to 0.0035 in
Oil Ring0.001 to 0.0025 in
Piston Ring End Gap
Cylinder bore oversizeRing SizeEnd Gap
Standard to 0.009 inStandard0.007 to 0.045 in
0.010 to 0.019 in0.020 in0.007 to 0.017 in
0.020 to 0.024 in0.020 in0.007 to 0.029 in
0.025 to 0.029 in0.030 in0.007 to 0.017 in
0.030 to 0.034 in0.030 in0.007 to 0.029 in
0.035 to 0.039 in0.040 in0.007 to 0.017 in
0.040 in0.040 in0.007 to 0.017 in
Piston Pin Diameter0.8119 to 0.8121 in
Piston Pin-to-Piston Clearance
Standard0.0001 in
Service Limit0.0003 in
Connecting Rod End Play0.004 to 0.010 in

Crankshaft and Flywheel
Main Journal
Diameter2.3331 to 2.3341 in
Taper Limit0.001 in
Out of Round Limit0.001 in
Main Bearing Oil Clearance
Standard0.0003 in
Service Limit0.0029 in
Connecting Rod Journal
Diameter1.9375 to 1.9383 in
Taper Limit0.001 in
Out-of-Round0.001 in
Connecting Rod Bearing Oil Clearance
Standard0.001 in
Service Limit0.0019 in
Crankshaft End Play0.004 to 0.006 in
Flywheel Clutch Face Runout Limit0.005 in

Bearing Journal Diameter
Number 12.1860 to 2.1855 in
Number 22.1225 to 2.1215 in
Number 32.0600 to 2.0590 in
Number 41.6230 to 1.6225 in
Bearing Oil Clearance
Standard0.001 in
Service Limit0.0025 in
End Play0.004 to 0.007 in

Cylinder Head and Valve Train
Head Warpage Limit
L-head1/32 in
F-head0.010 in
Valve Seat Angle45
Valve Seat Width3/32 to 1/8 in
Valve Seat Runout Limit0.002 in
Valve Face Angle45
Valve Margin Width1/32 in minimum
Valve Stem Diameter
Intake0.3733 to 0.3738 in
Exhaust0.371 to 0.372 in
Valve Stem-to-Guide Clearance
Intake0.0007 to 0.0022 in
Exhaust0.0025 to 0.0045 in
Valve Spring Free Length(intake and exhaust0
L-head2.50 in
F-head1.97 in
Valve Spring Pressure(lbs at specified length)
Standard120 at 1.750 in
Service Limit110 at 1.750 in
Standard53 at 2.109 in
Service Limit47 at 2.109 in
Lifter TypeMechanical
Lifter Diameter0.6245 to 0.6240 in
Lifter-to-Bore Clearance0.0005 to 0.002 in

Oil Pump
Early model L-head Engine(to engine S/N 44417)
Rotor End Play0.002 to 0.005 in
Pump Shaft End Play0.002 to 0.004 in
Late model L-head Engine(engine S/N 44417 and on)
Rotor Lobe Clearance0.010 in or less
Rotor End Play0.004 in
Outer Rotor-to-Pump
Body Clearance
0.012 in or less
Rotor Thickness Variance0.001 in or less
Driven Gear-to-Pump
Body Running Clearance
L-head0.003 to 0.010 in
F-head0.022 to 0.051 in
Pump Cover Warpage Limit0.001 in

Oversize and Undersize Component Code Letter Definition
Code Letter
AMain and connecting rod bearing0.010 in undersize
BPistons0.010 in oversize
ABCombination of A and B

Torque Specifications FT-LbsNm
Camshaft Thrust Plate Bolt2635
Camshaft Gear or Sprocket Bolts30 to 4041 to 55
Main Bearing Cap Bolts65 to 7588 to 101
Connecting Rod Cap Nuts35 to 4548 to 61
Cylinder Head Bolts60 to 7082 to 95
Flywheel Bolts35 to 4148 to 55
Manifold Assembly Bolts29 to 3533 to 48
Oil Pan Bolts9 to 1412 to 19
Piston Pin Lock Screw35 to 4148 to 55
Spark Plugs25 to 3334 to 48
Rocker Arm Cover Nuts(F-head)7 to 109.5 to 13.6
Rocker Arm Assembly Nuts(F-head)30 to 3641 to 48
Valve Lifter Cover Bolts(all)7 to 109.5 to 13.6
Water Outlet Bolts20 to 2527 to 34
Water Pump Bolts12 to 1716 to 23