Fig. 17 - Checking valve guide wear.
Installing cylinder heads
Cylinder head securing screws should be tightened evenly following
the cross sequence shown in figure to a 2 kgm (19 Nm) torque, then
repeat tightening in the shown sequence to a 5 kgm (49 Nm) torque,
finally use n. 5.9030.640.0 equipment to furtherly tighten the cap
screws until each of them is locked by an angle of 90°
±
5’.
Before performing screw tightening, the use of plate A is recom-
mended to align the cylinder heads correctly, as shown in figure
21.
Checking engine compression
Run the engine until the operating temperature is attained.
Remove the injection nozzle from the cylinder head and fit the
special engine compression tester.
Ensure the injection pump is in STOP position.
Start the engine and let it turn until the peak pressure in the
cylinders is obtained and then check the engine r.p.m.
Be sure the same checking procedure is applied for each single
cylinder so as to provide even measurements.
Cylinder pressure should be 25 to 30 bar at sea level at 150 engine
r.p.m. and with hot oil.
Any difference in readings should be no more than 10%. Altitude
affects engine compression: 4% pressure loss every 300 m above
sea level is usually recorded. To avoid incorrect readings, the
battery should be thoroughly efficient. Lack of compression may
be due either to piston ring or valve and valve seat or cylinder
wear.
Fig. 21 - Using alignment plate A to install the cylinder heads and cap
screw tightening order.
Fig. 18 - Inserting valve guides with the special
tool.
Fig. 19 - Adjusting valve clearance.
Fig. 20 - Checking cylinder compression.
Fig. 22 - No. 5.9030.640.0 equipment for tighte-
ning the cylinder head securing screws angularly.
engine
cylinder head
14
1
49
www.maskinisten.net
www.classicmachinery.net
To Next Page
Loading...
