Mitsubishi S4S Service Manual page 99

(5) Measuring piston protrusion
If the piston protrusion is not correct, check the
various parts for clearance. Measure the piston
protrusion as outlined below.
(a) Measure the top dead center of the pistons
with a dial gage.
(b) Install the dial indicator on the top of the
crankcase. Set the indicator to read 0.0 mm
[0.000 in.].
(c) Measure the piston protrusion at least three
locations on the top ofthe piston and average
the three measurements to check the
protrusion. Subtract the projection from the
compressed thickness of the cylinder head
gasket to check the clearance between the
piston top and the cylinder head.
Unit: mm [in.]
Item
Assembly Standard
Direct
0.05 to 0.45
Piston
injection [0.0020 to 0.0177]
protrusion
Swirl -0.25 to 0.15
chamber [-0.0098 to 0.0059]
Compressed thickness 1.2±0.05
of cylinder head gasket [0.05±0.002]
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l
& CAUTION
f - - - - - - - ,
Incorrect piston protrusion affects engine
performance and causes valve interference with
the piston.
ENGINE MAIN PARTS
Measuring piston protrusion
7-37