WÄRTSILÄ 41508, Инструкция по эксплуатации

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valves as well as inlet valves are then somewhat open and scavenging
takes place. If the crankshaft is turned to and fro near this TDC, both
exhaust and inlet valves will move, a fact that indicates that the
crankshaft is near the position which can be named
TDC at scaveng-
ing.
b)
The second time is after the compression stroke and before the
working stroke. Slightly before this TDC the fuel injection takes place
(on an engine in operation) and this TDC can therefore be defined
TDC
at firing. Characteristic is that all valves are closed and do not move
if the crankshaft is turned. When watching the camshaft and the
injection pump it is possible to note that the pump tappet roller is on
the lifting side of the fuel cam.
Marking of the flywheel. The flywheel is divided in 360°, starting from
TDC at firing for cylinder 1. TDC at firing for every cylinder is marked
on the flywheel. There is a common marking for the cylinders in engines
with even cylinder numbers, one cylinder is at TDC at firing and the other
is at TDC at scavenging. There are separate scales for A- and B-bank in a
V-engine. See also the firing order in chapter 01. Firing interval, in crank
angles, can be determined by dividing 720° with the number of cylinder.
Example of reading the flywheel
Example: On a VASA 12V32 engine, the fuel timing is read to 17° for
cylinder A2 when the flywheel is in the position shown in the above figure.
5
0
1
0
0
5
5
4
4
3
3
2
2
1
1
0
6
0
1
1
0
C
l
o
c
k
w
i
s
e
r
o
t
a
t
i
n
g
e
n
g
i
n
e
1
3
0
8
0
1
2
0
C
Y
L
A
2
,
5
T
D
C
7
0
17˚
Cyl A2
TDC
Fig 00-3
3200538935
Contents, Instructions, Terminology 34SG-200328-02