Lombardini LDW 502 Workshop Manual page 54

DISASSEMBLY/REASSEMBLY
II
COMPILER TECO/ATI
54
MAIN BEARING CAPS / BEARINGS- CENTER
The center main caps are referenced on the actual cap and on the
crankcase as shown to allow replacement of the caps in the identical
position of removal. The reference number locations are shown in the
figure at the left. Always reposition main caps in the original position.
NOTE: If main bearings are intended to be re-used following
disassembly, mark the bearing position using a permanent marker.
INSPECTION / CLEANING: Clean the main bearing caps in solvent
and dry with compressed air. Remove all dirt, oil and deposits from
the bearing seats. Check/ clean all oil passages and remove any and
all impurities. Flush the oil passages with clean solvent before
assembling the crankshaft.
crankcase for cracks, signs of overheating, nicks, etc. Inspect the
main bearings for wear and signs of oil starvation, pitting, scoring,
etc. Thoroughly scrub, but do not damage the non-bearing surface
(back side) of the main bearings if re-use is intended. Replace the
main bearings if any doubt exists.
BEARING INSTALLATION / TORQUE SPECIFICATION. Install the
main bearings (upper and lower) into the respective bearing seats/
caps aligning the "tang" on the bearing with the "slot" in the seat or
cap. Liberally oil the bearing surface with clean engine oil. Install the
main bearing caps with reference to original position (see above).
Torque the main bearing caps to 60 Nm in 10 Nm steps.
FRONT / REAR MAIN BEARING CAPS / BEARINGS
The front and rear main bearings of the FOCS engine are designed
with lateral seals (2) installed between the sides of the main bearing
cap and the crankcase saddle. The lateral seals MUST be replaced
each time the main bearing caps are removed. Thoroughly clean the
main bearing cap and crankcase as described above. Install and
lubricate the main bearings as described above. Install the thrust
bearings (rear main only) as described on page 43. Install the lateral
seals onto the main bearing cap(1). Liberally lubricate the exterior of
the seals. Place the special shims (part no. 1460-053) as shown in
the figure between the crankcase and the main bearing. Push the
main bearing into place.
Torque the front and rear main bearing caps to 60 Nm in 10 Nm
steps. Following installation, the lateral seal must extended 0.5-
1.0mm past the crankcase planes(A) at the front and rear face of the
crankcase and 0.5-1.0mm past the oil pan plane(B) to allow
complete sealing. Trim material in excess of 1.00mm with a razor
knife. NOTE: Prior to installation of the rear seal support, oil pump or
the oil pan, apply a small amount of RTV Silicone to the lateral seal
extended area.
MAIN BEARING CLEARANCE
Ideally, main bearing clearance is determined following actual
measurement of the main bearing journals and the main bearing
diameters. "PLASTIGAGE" however, can provide a quick and
reasonably accurate determination of main bearing clearance.
Review and
"PLASTIGAGE" kit. Invert (if possible) the engine so that the
crankshaft weight is directed away from the main bearing cap.
Remove the main bearing cap in question. Clean all oil from the
main bearing and crankshaft using a spray solvent. Place a small
strip of PLASTIGAGE across the main bearing as shown at (A).
Install and torque the main bearing to 60 Nm. DO NOT ROTATE
THE ENGINE!. Remove the main bearing cap and compare the width
of the compressed PLASTIGAGE strip to the "KEY" provided with the
PLASTIGAGE (as shown) to determine the bearing clearance.
PISTON COOLING JETS- LDW 1204/T: The LDW 1204/T engine is
equipped with cooling jets which spray engine oil on the underside of
the piston providing additional engine cooling. The cooling jets attach
to the crankcase directly adjacent to the lower cylinder.
COMPONENTS:
1 Washer
2 Nozzle
3 Washer
4 Banjo Bolt
5 Check Ball
6 Spring
INSPECTION / CLEANING / INSTALLATION: Inspect the spray jets
for damage and clogging. Using new washers(1),(3), affix the
nozzle(2) to the crankcase with bolt(4). Slowly rotate the engine to
BDC (each cylinder). Adjust the position of the nozzle(2) so that no
contact is made with the piston at BDC and the nozzle is pointed at
the center of the piston bottom. Torque the bolt (4)
REG. CODE
MODEL N°
1-5302-351 50563
Inspect the main bearing caps and
Remove the shims (part no. 1460-053).
understand the instructions
SPECIFICATIONS:
A = 0.80 / 0.85mm
B = 34mm
C = 150mm
D = 16mm
a = 5°
DATE OF ISSUE
04
REVISION
04.90
provided with the
DATE ENDORSED
15.11.99