Nanni N4.40, Workshop Manual, Page: 135 / 175

ENGINE
03-M-E3B, 03-M-DI-E3B, 03-M-E3BG, WSM
1-S65
Pistons
[D1503-M, D1703-M, D1803-M, V2003-M, V2203-M, V2403-M,
V2403-M-T, D1703-M-BG, V2003-M-BG, V2003-M-T-BG,
V2203-M-BG, V2403-M-BG]
1. Fully clean the carbon (1) in the cylinders.
2. Remove the connecting rod cap (3).
3. Turn the flywheel and move the piston to the top dead center.
4. Lightly tap the piston from the bottom of the crankcase with the
grip of a hammer to pull the piston out.
5. Pull out the other piston in the same procedure as above.
(When reassembling)
• Before you install the piston into the cylinder, apply sufficient
engine oil to the piston.
• When you install the piston into the cylinder, point the mark on
the connecting rod to the injection pump.
IMPORTANT
• Do not change the combination of cylinder and piston.
Align the position of each piston by the its mark. For
example, mark "1" on the No. 1 piston.
• Set the piston rings with their gaps at 0.79 rad (45 °) from
the direction of the piston pin (see the figure).
• Install the pistons with a piston ring compressor (6)
carefully.
• When you install the piston in position, do not give a
damage to the layer of molybdenum disulfide on the piston
skirt. This layer can decrease the clearance with the
cylinder liner. Immediately after you press-fit the piston
pin, the piston is hot and the layer comes off easily. Only
put in the piston after its temperature decreases.
M00000003ENS0095US1
Tightening torque Connecting rod screw
45 to 49 N·m
4.5 to 5.0 kgf·m
33 to 36 lbf·ft
(1) Carbon
(2) Connecting Rod Screw
(3) Connecting Rod Cap
(4) Connecting Rod
(5) Layer of Molybdenum Disulfide
(6) Piston Ring Compressor (A) Top Ring Gap
(B) Second Ring Gap
(C) Oil Ring Gap
(D) Piston Pin Hole
(a) 0.79 rad (45 °)
KiSC issued 06, 2009 A