Jeep 1987 Wrangler Workshop Manual page 343

ENGINES
m
4.2 LITER (258 CID) SIX-CYLINDER ENGINE
m
SPECIF1CAT101S
Six-Cylinder Engine Specifications
(USA) (METRIC)
I n c h e s Millimeters
U n l e s s U n l e s s
O t h e r w i s e O t h e r w i s e
S p e c i f i e d S p e c i f i e d
Type In-Llne, OMV, Six-Cylinder
Bore 3.75
05.25
Stroke 3.895 98.93
Displacement 258 cubic inches 4.2 IHer
Compression Ratio 8.6:1
Compression Pressure 120-150 pel 827-1034 kPa
Maximum Variation Between
Cylinders 30 psi 206 kPa
Firing Order 1-5-3-6-2-4
Taxable Horsepower 33.75 Bhp 25.2 kW
Fuel unleaded
C a m s h a f t
Fuel Pump Eccentric Diameter ...... 1.615-1.625 41.02-41.28
Tappet Clearance. Zero Lash (hydraulic tappets)
End Play Zero (engine operating)
Bearing Clearance 0.001-0.003 0.025-0076
Bearing Journal Diameter
No. 1 2.029-2.030 51.54-51.56
No. 2 2.019-2.020 51.28-51.31
No. 3 2.009-2.010 51.03-51.05
No. 4 1.999-2.000 50.78-50.80
Base Circle Runout 0.001 (max) 0.03 (max)
Cam Lobe Lift 0.253 6.43
Valve Lift 0.405 10.29
Intake Valve Timing
Opens. 9« BTDC
Closes. 73* ABDC
Exhaust Valve Timing
Opens 57- BBDC
Closes 25° ATDC
Vslve Overlap .. 34°
Intake Duration 262°
Exhaust Duration. 262°
(USA)
Inches
Unless
O t h e r w i s e
Specified
Connecting Rods
Total Weight (less bearings) 695-703
Total Length (center-to-center) 5.873-5.877
Piston Pin Bore Diameter 0.9288-0.9298
Connecting Rod Bore
(less bearings) 2.2085-2.2080
Bearing Clearance 0.001-0.003
(0.0015-0.002
preferred)
Side Clearance 0.010-0.019
Maximum Twist 0.001 per inch
Maximum Bend 0.0005
per inch
Crankshaft
End Play. . 0.0015-0.0065
Main Bearing Journal Diameter 2.4996-2.5001
Main Bearing Journal Width
No. 1 1.086-1.098
No. 3 1.271-1.273
No. 2-4-5-6-7 1.182-1.188
Main Bearing Clearance 0.001-0.0025
(0.002
preferred)
Connecting Rod Journal
Diameter 2.0934-2.0955
Connecting Rod Journal Width...... 1.0^0-1.076
Maximum Out-of-Round
(All Journals) 0.0005
Maximum Taper (All Journals)....... 0.0005
C f f l n ^ e r Block
Deck Height 9.487-9.493
Deck Clearance 0.0148
(below block)
(METRIC)
Millimeters
U n l e s s
Otherwise
Specified
149.17-149.28
23.59-23.62
56.0^56.08
0.03-0.08
(0.044-.05
preferred)
0.25-0.48
0.025 per
25.4
mm
0.0127 per
25.4 mm
0.038-0.165
63.489-63.502
27.58-27.89
32.28-32.33
30.02-30.18
0.03-0.06
(0.051
preferred)
53.17- 53.23
27.18- 27.33
0.013
0.013
240.97-241.12
0.376
(below block)
SEE
I.S.
N
O
T
E
S
86218
B-109