EM-48 ENGINE MECHANICAL h Cylinder Head
Both intake and exhaust
Bushing bore mm (in.)
11.000 - 11.027
(0.433 1 - 0.4341 I Bushing size
.’ Use STD
Over 11.027
(0.434 1) Use O/S 0.05 10. IF NECESSARY, REPLACE VALVE GUIDE BUSHINGS
(a) insert an old valve wrapped with tape into the valve
guide bushing and break off the.valve guide bushing
by hitting it with a hammer.
CAUTION: Be careful.not to damage the lifter hole.
(b) Gradu
9O”C(’ .
ally heat the cylinder head to approx.
194OF).
(c) Using SST and hammer, drive out valve guide bush-
ing.
SST 09201-70010
(d) Using a caliper gauge, measure the valve guide bore
of the cylinder head.
(e) Select a new valve guide bushing.
If the valve guide bushing bore of the cylinder head is
more than 11.027 mm (0.4341 in.), machine the bore to
the following dimensions.
Rebored valve guide bushing bore dimension:
11.050 - 11.077 mm (0.4350 - 0.4381 in.1
EM-80 ’ ENGINE MECHANICAL .- Cylinder. Block
BORING OF CYLINDERS
NOTE; .-
l Bore all six cylinders for the oversized piston. outside
diameter.
l Replace the piston rings with ones to match, the over-
sized pistons.
1.
2.
3. SELECT OVERSIZED PISTON
Oversized piston diameter:
O/S, 0.50 7M-GE 83.40 - 83.45 mm
(3.2835 - 3.2854 in.)
7M-GTE 8341.. - 83.46.mm
(3.2839 - 3.2858 in.)
CALCULATE AMOUNT TO BORE CYLINDER
(a) Using a micrometer, measure the piston diameter at a
right angle to the piston pin hole center line, 22 mm
(0.87 in.) from the piston head.
(b) Calculate the amount each cylinder is to be rebored
as follows:
Size to be rebored = P + C - H
P = Piston diameter
C = Piston clearance
7M-GE 0.08 - 0.10 mm
(0.0020 - 0.0028 in.1
7M-GTE 0.07 - 0.09 mm
(0.0028 - 0.0035 in.)
H = Allowance for honing
0.02 mm (0.0008 in.) or less
BORE AND HONE CYLINDERS TO CALCULATED
DIMENSIONS
Maximum honing: 0.02 mm (0.0008 in.)
CAUTION: Excess honing will destroy the finished
roundness.
