Page 653 of 1691

block. Determine oil clearance. Clearance must be within
specification. See VALVE LIFTERS table under ENGINE SPECIFICATIONS.
Cylinder block can be bored for oversize lifters.
CYLINDER BLOCK ASSEMBLY
Piston & Rod Assembly
Install piston with notch or groove on top of piston toward
front of engine (timing chain end) with larger chamfer of connecting
rod bore toward crankshaft journal fillet.
Fitting Pistons
1) Measure piston diameter at top of piston skirt at 90-
degree angle to piston pin axis. Measure cylinder bore diameter below
top surface of cylinder bore, middle of bore and bottom of cylinder
bore.
NOTE: Piston diameter and cylinder bore should be measured at room
temperature of 70
F (21C).
2) Ensure piston diameter and clearance are within
specification. See PISTONS, PINS & RINGS table under ENGINE
SPECIFICATIONS.
Piston Rings
1) Ensure ring end gap and side clearances are within
specification. See PISTONS, PINS & RINGS table under ENGINE
SPECIFICATIONS.
2) Position piston ring gaps in proper location. See Fig. 16.
Compression ring gaps must be staggered so they do not align with oil
ring rail gap. Ensure identification marks (drill point, letter "O",
an oval depression or the word TOP) on compression rings face upward.
Fig. 16: Positioning Piston Rings
Courtesy of Chrysler Corp.
Rod Bearings
1) Crankshaft is marked to indicate undersize rod bearings.
See SPECIAL ENGINE MARKS. When replacing connecting rod bearings,
ensure connecting rod is installed with larger chamfer of connecting
rod bore toward crankshaft journal fillet.
2) Apply light coat of engine oil to connecting rod bolt
threads before tightening nut to specification. See TORQUE
SPECIFICATIONS table. Ensure oil clearance and side play are within
specification. See CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS table
under ENGINE SPECIFICATIONS.
Crankshaft & Main Bearings
1) Crankshaft is marked to indicate undersize main bearings.
See SPECIAL ENGINE MARKS. Main bearing cap location and direction of
installation should be marked before removal.
Page 654 of 1691

2) Ensure journal diameter, taper and out-of-round are within
specification. See CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS table
under ENGINE SPECIFICATIONS. Upper main bearings contain oil holes,
while lower bearings installed in main bearing cap do not.
3) Apply light coat of engine oil to threads before
tightening bolt to specification. See TORQUE SPECIFICATIONS table.
Ensure oil clearance and end play are within specification. See
CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS table.
CAUTION: Crankshaft journal grinding should not exceed .012" (.30 mm)
under standard size. DO NOT grind thrust surfaces of No. 3
main bearing. Final paper or cloth polishing after regrind
must be done in same direction as engine rotation.
Thrust Bearing
Thrust bearing is located on No. 3 main bearing. Replace
thrust bearing if crankshaft end play is not within specification. See
CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS table under ENGINE
SPECIFICATIONS.
NOTE: Cylinder bore should be measured at room temperature of 70
F
(21C).
Cylinder Block
1) Check cylinder bore, out-of-round and taper. Measure
cylinder bore diameter below top surface of cylinder bore, middle of
bore and bottom of cylinder bore. Bore cylinder block if bore diameter
is not within specification. See CYLINDER BLOCK table under ENGINE
SPECIFICATIONS.
NOTE: Cylinder block is marked to indicate oversize valve lifters.
See SPECIAL ENGINE MARKS.
2) Check valve lifter bore diameter. Check for scoring. If
scoring exists or lifter bore diameter is not within specification,
ream cylinder block bore for next oversize valve lifter. See VALVE
LIFTERS table under ENGINE SPECIFICATIONS.
ENGINE OILING
ENGINE LUBRICATION SYSTEM
System has a rotor-type oil pump and full-flow oil filter.
Oil is forced by pump through a series of oil passages in engine to
provide lubrication to engine components. Oil is supplied to rocker
assembly through hollow push rods. Push rods are fed oil from lifters.
See Fig. 17 .
Crankcase Capacity
On 3.9L, oil capacity with oil filter is 4.0 qts. (3.8L). On
5.2L and 5.9L, oil capacity with oil filter is 5.0 qts. (4.7L).
Oil Pressure
Oil pressure is 6 psi (.4 kg/cm
) at idle and 30-80 psi (2.1-
5.6 kg/cm) at 3000 RPM with engine at normal operating temperature.
Page 655 of 1691
Fig. 17: Cross-Sectional View Of Engine Oil Circuit
Courtesy of Chrysler Corp.
OIL LINE PLUG
1) The oil line plug is located in vertical passage in rear
of block between oil-to-filter and oil-from-filter passages. See
Fig. 18 . Missing or improperly installed plug could cause erratic, low
or no oil pressure.
2) To check installation, remove oil sending unit and insert
wire down passage. Oil line plug should be 7.50-7.68 in. (190.0-195.2
mm) from machined surface of block. If plug is too high, use suitable
dowel to position properly. If plug is too low, remove oil pan, oil
pump and rear main bearing cap. Use suitable dowel to position
properly.
3) To remove for passage cleaning or plug replacement, drive
plug from oil sending unit hole out bottom of block. When installing
Page 658 of 1691