MAN – 086 – ENG - 23
ENGINE CRANKSHAFT
MATCHING THE PISTON
Bearing seat diameter on new engine
Refer to the attached table to define the state of wear
of the drive shafts.
The replacement operation must be carried out when
size is lower than 0.03mm vs. original.
ATTENTION:
Clearance between piston and liner must be:
0.090 / 0.095mm.
If clearance is higher than 0.14mm, the piston
must be replaced.
MAX ALLOWED OVALIZATION ON
CONROD
Max. allowed ovalization between A and B on new
conrod: 0.002mm
Max. allowed ovalization between A and B on used
conrod: 0.01mm
An inspection must be carried out after about
30 hours use. When ovalization reaches 0,01mm
(the difference between the measured diameter in the
positions shown below
“A”
and
“B”
) the conrod must
be replaced.
The replacement operation must be carried out about
a use of 60 hours.
An inspection must be carried out after about a
use of 45 litres or 5 hours of use, and the pistons are
measured at 17.5mm from bottom.
The replacement operation must be carried out about
a use of 10 hours or 80 litres.
Size of the liner to be matched with piston is
marked on top of piston.
Allowed ring gap 0.15÷0.40 mm.
ESTIMATED AVERAGE LIFE OTHER
COMPONENTS
Big End Conrod Roller
B Crankpin
+ silver washers
= 30 hours
Little End Conrod
Roller B Piston
Pin
= 10 to 20 hours
WEAR STATUS EVALUATION CHART
21
