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Workshop Manual_3 - 4 LD_cod. ED0053025560_
4° ed
_ rev.
03
Disassembly / Reassembly
Piston ring assembly order
3LD 450, 3LD 450/S, 3LD 510, 3LD 510/S, picture 30
A
= slot for first piston ring (chromium plated)
B
= slot for piston ring segment (torsional)
C
= slot for third piston ring (oil scraper ring)
4LD 640, 4LD 705, 4LD 820, picture 31
A
= slot for first piston ring (chromium plated)
B
= slot for second piston ring (torsional)
C
= slot for third piston ring(torsional)
D
= slot for fourth piston ring(oil scrarper ring)
Note:
before inserting the piston in the cylinder, oil the piston
ringwith engine oil and turn them, thus the cuts are
misaligned.
Piston reassembly
Important
Lubricate the following parts with oil before mounting: the piston
pin, the piston, the cylinder and the big-end bearing.
Couple the piston with the connecting rod, thus the combustion
chamber centre
B
is perpendicularly under end
A
of the nozzle
housed inside the head.
Lubricate the piston pin and insert it in the piston, lightly
pressing with your thumb.
Make sure that the two stop rings are well housed inside their
seats.
Clearance volume
A
= Clearance volume
B
= Head gasket
The thickness
B
head gasket determines the clearance volume
A
which shall be 0.75 ÷ 0.90 mm for 3LD 450, 3LD 451/S, 3LD
510, 3LD 510/S and 0.80 ÷ 1.00 mm for 4LD 640, 4LD 705, 4LD
820.
Measure the piston crown position as to the cylinder surface
and chose a gasket having a suitable thickness.
Always consider that the piston at the top dead centre could be
at the same level, either under or over the cylinder.
Summary of Contents for 3LD 450
Page 1: ...WORKSHOP MANUAL Engine Series 3 4 LD ...
Page 9: ... 9 Workshop Manual_3 4 LD_cod ED0053025560_4 ed_ rev 03 ...
Page 45: ... 45 Workshop Manual_3 4 LD_cod ED0053025560_4 ed_ rev 03 ...
Page 46: ... 46 Workshop Manual__3 4 LD_cod ED0053025560_4 ed_ rev 03 ...
Page 47: ... 47 Workshop Manual_3 4 LD_cod ED0053025560_4 ed_ rev 03 ...
