Lexus SC300 / Lexus SC400. Manual - part 389

CYLINDER BLOCK ASSEMBLY

EG1KW–01

(See Components for Cylinder block Disassembly and As-

sembly)
HINT:

•

Thoroughly clean all parts to be assembled.

•

Before installing the parts, apply new engine oil to all
sliding and and rotating surfaces.

•

Replace all gaskets. O–rings and oil seals with new
parts.

1. 

INSTALL MAIN BEARINGS
HINT:

•

Main bearings come in widths of 19.5 mm (0.768 in.) and
22.5 mm (0.886 in.). Install the 22.5 mm (0.886 in.)
bearings in the No.1 and No.5 cylinder block journal
positions with the main bearing cap. Install the 19.5 mm
(0.768 in.) bearings in the other positions.

•

Upper bearings have an oil groove and oil holes lower
bearings do not.

(a)  Align the bearing law with the claw groove of the cylinder

block, and push in the 5 upper bearings.

(b)  Align the bearing claw with the claw groove of the main

bearing cap, and push in the 5 lower bearings.
HINT: A number is marked on each main bearing cap to indi-
cate the installation position.

2. 

INSTALL UPPER THRUST WASHERS
Install the 2 thrust washers under the No.3 journal position of
the cylinder block with the oil grooves facing outward.

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ENGINE MECHANICAL

EG–179

3. 

PLACE CRANKSHAFT ON CYLINDER BLOCK

4. 

INSTALL MAIN BEARING CAPS AND LOWER THRUST
WASHERS

A.

Place main bearing caps and lower thrust washers on
cylinder block

(a)  Install the 2 thrust washers on the No.3 bearing cap with the

grooves facing outward.

(b)  Install the 5 main bearing caps in their proper locations.

HINT: Place the bearing caps level and let them return to their
original position by their own weight.
NOTICE: Do not install the main bearing cap by tapping
it.

B.  Install main bearing cap nuts

HINT:

•

The main bearing cap nuts are tightened in 2
progressive steps (steps (b) and (d)).

•

If any one of the main bearing cap stud nuts is broken
or deformed, replace it.

EG–180

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ENGINE MECHANICAL

(a)  Apply a light coat of engine oil on the threads and under the

main bearing cap nuts.

(b)  Install and uniformly tighten the 20 main bearing cap nuts in

several passes, in the sequence shown.

Torque: 27 N

⋅

m (275 kgf

⋅

cm, 20 ft

⋅

lbf)

If any one of the main bearing cap nuts does not meet the
torque specification, replace the main bearing cap stud bolt.

(c)  Mark the front of the main bearing cap nut with paint.

(d)  Retighten the main bearing cap bolts 90

 in the numerical

order shown.

(e) Check 

that the painted mark is now at a 90

 angle to the front.

C.

Install main bearing cap bolts

(a)  Install a new seal washer to the main bearing cap bolt.
(b)  Install and uniformly tighten the 10 main bearing cap bolts.

Torque: 49 N

⋅

m (500 kgf

⋅

cm, 36 ft

⋅

lbf)

(c)  Check that the crankshaft turns smoothly.

5. 

CHECK CRANKSHAFT THRUST CLEARANCE
Using a dial indicator, measure the thrust clearance while pry-
ing the crankshaft back and forth with a screwdriver.

Standard thrust clearance:

0.020 – 0.220 mm (0.0008 – 0.0087 in.)

Maximum thrust clearance:

0.30 mm (0.0118 in.)

If the thrust clearance is greater than maximum, replace the
thrust washers as a set.

Thrust washer thickness:

2.440 – 2.490 mm (0.0961 – 0.0980 in.)

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ENGINE MECHANICAL

EG–181

6. 

INSTALL PISTON AND CONNECTING ROD ASSEMBLES
Using a piston ring compressor, push the correctly numbered
piston and connecting rod assemblies into each cylinder with
the front mark of the piston facing forward.
NOTICE: The shape of the piston varies for the RH and LH
banks. The RH piston is marked with “R”, the LH piston
with “L”.

7. 

INSTALL CONNECTING ROD CAPS

A.

Place connecting rod cap on connecting rod

(a)  Match the numbered connecting rod cap with the connecting

rod.

(b)  Align the pin groove of the connecting rod cap with the pins

of the connecting rod, and install the connecting rod.

(c)  Check that the outside mark of the connecting rod cap is

facing in correct direction.

EG–182

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ENGINE MECHANICAL