Arona 15 hp (1968) marine engine
Arona 15 hp (1968) marine engine
Lombardini 9LD560
Arona CM 10/B
Index …………………….. Page 1
Specifications …………. Page 2
Operation……………….. Page 3
Maintenance …………… Page 4
Controls ………………… Page 5
Fuel system……………… Page 6
Injector pump …………………
Page 6
Injector and valve timing Page 9
Injector cam housing
Removal and refitting…………. Page 10
Camshaft ……………………... Page 11
Tappets………………………… Page 11
Cylinder head removal………. Page 12
Oil system ……………. Page 13
Cooling system…………. Page 14
Exhaust system………… Page 15
Arona 15 hp (1968) marine engine
Lombardini 9LD560
Arona CM 10/B
Piston rings
Opel 1,5Ltr. "Rekord" (Mot. II. Phase) 3006 ES 80x2,5+2,5+5mm Standard
4-stroke direct injection diesel
Piston diameter and stroke = 80 x 85mm
Piston displacement 854cc
Max cylinder ovality 0.2mm
Max cylinder re-boring = 0.7mm
Top piston ring is chromed
Arona piston ring part nos. from top to bottom:7390
Replacement consumables and cross-references
Fuel Filter
Oil filter
Piston rings
Valve guides
Crosland 450
FIAAM FA4194/2
Opel 1,5Ltr. "Rekord" (Mot. II. Phase) 3006 ES 80x2,5+2,5+5mm Standard
Re-machined from a Renault master 2.5 with oil seals.
Manufacturer: - Fausto Arona & sons Voghera Italy
UK Importer E.P. Barrus
4 cycle direct injection 2 cylinder diesel engine
15 hp @ 2500 rpm 12 – 12½ hp @ 2200rpm
Weight 135 Kgs 297 Lbs (=1hp/9Kgs)
Oils Winter SAE 20/20 Summer SAE30
Valve clearance 0.016” cold (0.4mm)
Valve seat angle 120º
Displacement volume 854cc
Piston stroke 85mm
Cylinder diameter 80mm
Max cylinder ovality 0.2mm
Max cylinder re-bore 0.7mm
Injector calibration 2560/2702 Lb/In² (180/190 Kg/cm²)
Injector markings:- Bosch PFR2K05
ut = 82
b = ±0.2
Injector pressure
2560 – 2700 psi
Oil pressure Max. 68psi Min. 25psi
Engine Cycle
(One turn of the starter handle = 2 rotations of the crankshaft)
Cylinder 1 is the cylinder nearest to the flywheel (front end).
Cylinder 2 precedes cylinder 1 by 180º of rotation in the following cycle.
TDC = Top dead centre BTDC = Before Top dead centre ATDC = After top dead centre
° of
Cylinder 1
Inlet valve opens (8º BTDC) Exhaust valve closes. (8º
= PMS 1
Air drawn in.
Inlet valve closes (223º)
Compression starts.
Fuel Injection starts (331º) (29º BTDC) = AP
= PMS 1
Fuel Injection ends (356º) (4º BTDC)
1 Power stroke starts
Exhaust valve opens (137º ATDC)
Exhaust gases purged.
Inlet valve opens (8ºBTDC) Exhaust valve closes (8º
= PMS 1
Air drawn in.
Output rotation anticlockwise as viewed from the rear.
Torque settings
Cylinder head bolts (5)
Cam shaft bearings
Injector pump mountings
Exhaust manifold
Fuel filter
40 Lb/ft (11½ Lb/ft 5.2Kgf)
30 Lb/ft
20 Lb/ft
Diesel DERV heavy oil (35sec)
Crosland 450
Oil Change
Oil filter
Fuel filter
Every 90 Hours
every 90 hours
every 200 hours
Governor control or throttle
Fuel system
Fuel injector pump
The injector pump comprises of: Body
Non-return valve assembly
Piston assembly
Return Springs
Cam lever follower assembly
To injector
Non-return valve
Valve body
Injector piston body
Injector piston
The non-return valve assembly casing has
a copper washer which seals to the valve
Piston return spring
body when the casing is screwed into the
injector pump body. This is critical as the
Cam lever follower
further the casing is screwed into the pump
body the more it compresses the non-return
valve spring which affects the delivery pressure to the injector. The valve body has
machined faces top and bottom, which ensure no internal leakage of fuel.
The piston travels up and down inside the piston body. The
Spill port
piston has a slanted slot and a central duct extending from the
top to halfway down the piston. The injector piston body has a
spill port. As the piston travels upwards the fuel spills out until
the slot is no longer over the port. The remainder of the piston
travel forces fuel through the non-return valve to the injector. As
the piston travels downward a vacuum forms above the piston
until the slot is again uncovered by the port, when more fuel is
drawn into the piston chamber. The piston is rotated by the
governor arm, which moves a rack back and forth. This rack in
turn rotates pinions, which have a slot into which the bottom
rectangular flange of the piston is located. The rotation of the
pistons control the point in the piston stroke at which fuel ceases
to spill back through the port thus increasing and increasing the effective delivery stroke of
the piston. This in turn dictates the amount of fuel delivered to the injectors in any given
Pump Dismantling
Undo and remove the Non-return valve assembly casing. Inside there is a copper washer,
spring, valve and valve body. These should all drop out of the pump casing. The injector
piston body will also drop out from this opening.
On the side of the body there are two pins held in place by a spring wire. Withdraw the
spring wire. Depress the cam lever followers slightly against pressure from the return
springs. This will release the pins, which locate in a slot on the side of the cam follower
assembly and prevent the assembly from falling out of the body under pressure from the
piston return spring. When removed the cam follower assembly will be partially pushed by
the return springs. The follower assembly consists of a gudgeon pin and two concentric
rollers set into the follower body. After the follower assembly is removed, slide out the
spring, piston foot and piston. The spring retaining washer and pinion can then be
removed. Finally the rack can now be slid out.
Pump Reassembly
To determine the point of piston rotation at which there is no fuel delivery, carefully slide
the piston into the injector piston body fully home. Place a finger over the top of the injector
piston body making an airtight seal. As the piston is gently slid back and forth the sound of
a quick rush of air into the piston can be heard followed by a tiny puff of air as it is forced
out from under the finger. By rotating the piston in small amounts whilst it is being
“pumped” the amount of puff can be heard to increase or decrease. Continue this until the
puff gradually decreases and just ceases. It is at this point of rotation that engine cut-off is
set. This is also the point at which the governor arm is in line with the locating slot in the
cylinder block casing where the pin on the rack drops into the governor control arm. The
governor control arm can be set in this position by pushing the brass cut off button located
in the side of the cylinder block, just
above the injector pump position.
There is a locating slot in the injector
piston body, which is in line with the
spill port. Slide the piston body and
piston into the pump body engaging
the locating slot with the locating pin
inside the pump body, which faces
the side of the pump body where the
pinions are exposed. Take care not to disturb the cut-off position
the piston. Screw in the re-assembled non-return valve to hold the
piston body in position. Mark the orientation of the rectangular
locating flange at the bottom of the piston with a felt tip on the
bottom face of the injector body. Remove the piston. Insert the rack so that the rack pin is
at the cut-off position. Drop the pinion into position so that it engages with the rack and the
locating slot is aligned with the cut off rotation marks previously marked with felt tip. The
second pinion has a clamping screw. This also acts as a stop. This stop position should
also coincide with the cut-off position. When the piston body of the secondary pump is
removed, there is sufficient room to disengage the pinion from the rack and then reengage it so that the stop coincides with the cut-off position. After both pinions are reengaged the clamping screw can be slackened and the secondary location slot on the
pinion aligned with the primary. The clamping screw is then retightened. Both pistons
should now be set up so that they cease to deliver fuel when the rack is at the cut-off
position. Drop the spring retaining washer into the cam arm follower recess with the
washer recess facing up. Drop in the piston return spring. Slide the piston foot over the
piston flange and very carefully without using any force slide the piston into the piston
body taking care to orientate the piston flange so that it aligns with the pinion recess and
that the piston slot is facing towards the spill port i.e. the same side as the pinions are
exposed. Slide the follower assembly into the recess and over the spring and piston foot
ensuring that the slot aligns with the retaining pinholes. Depress the follower slightly
against the return spring and drop the retaining pins through their holes into the follower
slots. Slide the pin retaining spring wire across the heads of the pins through the hole in
the pump body and into the grooves set into the pinheads.
Injector Pump installation
By slackening off the two nuts on the lock cover
the pivot shaft for the cam levers can be
Lock cover
rotated. The mounting of the shaft is eccentric,
and therefore by rotating the shaft the axis of
the cam lever pivot can be raised or lowered.
The slot in
Injector pump
the face is
aligned with
eccentric so
that if the
vertical the
would be either at it lowest point or its highest point.
Do not adjust the stroke too high or the injector pump will be damaged.
By removing the non-return valve assembly at the injector pump union it is possible to
examine whether the injection occurs at the correct point in the engine’s cycle. This is the
point marked AP on the front of the flywheel housing. With the removal of the non-return
valve assembly fuel will flow through the pump and piston and out of the top of the union
until the injector piston is displaced to a point where the spill port is no longer in line with
the slanted slot. This is the point when the fuel is compressed in the injector body and fuel
injection commences. This should coincide with the AP marking on the flywheel (29º
To adjust cam lever setting: • Remove the side access cover plate
• Rotate the engine so that the levers
are not activating the pump pistons.
(i.e. at their lowest point)
• Slacken the lock nuts on the pivot
shaft locking plate and turn the pivot
shaft clockwise so that the levers are
just touching the followers on the
bottom of the injector pump. (the
eccentric pointing to the pump).
• Slacken the 2 locknuts on the lever
Lock nuts
arms and adjust the screw adjusters
so that they are just touching the pump followers equally. The followers should touch
so that the retaining pins for the cam lever follower assembly are not impacted on the
down stroke of the injector pistons and possibly shear.
• Screwing the adjusters up to advance and down to retard the timing can make at this
point fine adjustment. The adjusters may only be rotated upwards a maximum of 3
turns to prevent over displacement of the pump pistons and damage to the injector
The cam levers act on each of the two
individual injection pistons in the injector
pump. Adjust the clearance on the pump
followers by slackening off the lock nuts
and screwing the adjuster up or down.
When adjustments are complete retighten
the lock nuts.
View from side with access panel cover
Timing markings
(Note that the flywheel has no woodruff key
and may slip)
Timing markings on the flywheel housing.
AP = Injection point (29°BTDC) (Spill point)
PMS = Top dead centre (TDC)
Spill point
The spill point is found by removing the
injector pipe couplings at the injectors and
rotating the engine. As the engine is rotated
and the injector cam rises, fuel will seep from
the injector pipe. The spill point is the point
during engine rotation when the fuel seepage
Setting injector and valve timing
The injector timing, or spill point and valve timing is critical to the running of the engine.
In making both of these settings it should be noted that serious damage could result in
incorrect settings and procedures.
Note that the flywheel is attached to the crankshaft by sliding onto a taper and clamped
tight using two locknuts. There is no woodruff key and the flywheel may slip on the
crankshaft. It is therefore imperative to confirm TDC every time this procedure is carried
This procedure can be applied using either cylinder 1 or 2. Take care not to confuse these
during the setting up process.
Always rotate the engine in its normal direction of rotation when setting up the timing
positions, as this will ensure any slack in the drive trains for the injector pump and/or
camshaft will have been “taken up.”
1. Remove the valve/camshaft cover
2. Remove the injectors
3. Rotate the flywheel by hand until the TDC position can be felt by gently inserting a
piece of wire through the open injector port. Mark the TDC position on the flywheel
pulley. (Alignment with the PMS marking)
4. Mark the injector pump cam housing for the spill point
5. Remove the injector pump cam housing
6. Remove the valve chain coupling as necessary to realign or confirm alignment of
the missing teeth positions. The driving sprocket can be rotated using the starter
7. Rotate the camshaft so that the inlet and exhaust ports for cylinder 1 are rocking.
Rotation will be blocked if the piston is at or near TDC.
8. By carefully inserting a length of thin wire in the injector port and rotating the engine
slowly, the piston position can be felt and top dead centre (TDC) confirmed. Confirm
or mark the TDC positions for cylinders 1 and 2 on the flywheel.
9. Mark the camshaft “rocking” position on a visible part of the sprocket so that this
position can be confirmed with the valve cam cover in place.
10. Replace the injector pump cam housing taking care not to disturb any gear
positions when re-engaging the gear wheels.
11. Confirm TDC coincides with the valve rocking position for the correct cylinder. The
tips of the lobes should be equi-distant from top face of the cylinder head. Fine
adjustment of this timing is also made by slackening the three nuts that attach the
sprocket to the starter shaft using slotted holes (access through rear access panel)
and adjusting its relative position, then retightening the nuts.
12. From the TDC (PMS) rotate the flywheel to the AP position.
13. Remove the Injector pump cam housing.
14. Rotate the injector cam so that it is aligned 180º out from the previously marked
spill position.
15. Refit the Injector pump cam housing.
16. Confirm that the spill point coincides with the AP position on the flywheel for the
correct cylinder.
17. Confirm TDC coincides with the valve rocking position for the correct cylinder.
Removing and refitting the injector pump cam housing
3 mounting screws.
The injector pump cam housing can be accessed after removal of
the gearbox.
Disengage the cam levers from the injector pump by slackening
off the 2 nuts on the pivot shaft locking plate and rotating the pivot
shaft anticlockwise 90º
Mark the TDC position to aid refitting.
Injector pump cam plate.
After removal of the 3 mounting screws the cam plate can be
Underneath the plate within the governor housing can be seen from top to bottom the
governor wheel gear, the crankshaft gear and oil pump gear, Part of the governor arm can
also be seen.
The Injector pump cam housing includes a hollow gear with teeth
on both the inner and outer face. The inner face is driven by the
crankshaft gear and the outer face drives the oil pump and
governor wheel gears.
The refitting is the reverse of the above. Correct alignment of the
gears is essential for injector and valve timing. If this was correct
at removal take care not to disturb their positions.
Reset the injector cam pivot shaft by rotating it clockwise until
contact with the injector pump resistance is just felt. Turn the shaft
a further 1º so that the injector pump pistons bear down on the
cam levers and not the piston retaining pins.
It is essential to confirm that the valve timing has not been
Injector pump, spill timing should also be confirmed.
The camshaft is driven through a series of gears
in the governor housing finally being joined by a
chain coupling. The coupling consists of two
sprockets positioned face to face and a length of
drive chain wrapped around them. The chain has
a connector similar to a bicycle chain with a pin,
back- plate and clip. The sprockets each have a
tooth missing to aid future alignment. The relative
positions of the two sprockets to each other affect
the valve timing. Valve timing is also made by
slackening the
three nuts that
attach the sprocket to the starter shaft using slotted holes
(access through rear access panel) and adjusting its
relative position, then retightening the nuts. The TDC
position of the piston, indicated by the relative cylinder
mark (1 or 2) aligned with the PMS datum on the flywheel
housing should coincide with the camshaft lobes
“rocking” between the inlet closed and exhaust open
position for either cylinder 1 or 2 as appropriate.
Great care should be taken with the valve timing as incorrect timing may result in
valves impacting on the piston crowns.
Lubrication is through the camshaft bearing caps at either end of the shaft. Oil is delivered
through an external delivery pipe connecting to the hollow rocker cover studs.
The tappets are inverted cups with 4 small
lubricating holes. They are machine fitted in
the cylinder head recess for the double valve
springs. On the top of the valve stem is fitted
a small machined cap. This cap sits above
the valve spring retaining collets. It is by the
replacement of this cap with others of various
clearances are achieved.
Tip:- It is possible to make up gaps caused by
wear by making shim discs of appropriate
thicknesses out of a feeler gauge.
Valve clearance 0.016” cold (0.4mm)
The decompression (valve lifter) system is
provided by a flat plate lying across the top
edge of the 2 inlet tappets. A cam lever
mounted in the rocker cover acts on this plate
depressing the plate when the lever is rotated.
The plate presses down on the inlet tappets
and partially opens the inlet valves. The plate
is secured at one edge by two locknuts on
each of two studs. The plate floats freely
beneath the locknuts, and is held off the
tappets by a small spring located on the top of
the central cylinder head stud and bolt. The
locknuts are adjust by allowing the plate to rest horizontally on the tappets of the fully
closed inlet valves and locked down just touching the plate in this position.
Cylinder head removal
Oil System
Filter head assembly
Note that the non-return valve assembly
bolts through the body of the filter head.
Care must be taken to remove the filter
head casting before removing the NRV
assembly as the bolt, lock washer and
copper sealing washer will drop into the
gallery below the filter head when undone.
The NRV serves to prevent the oil
draining from the pipes that deliver oil to
the camshaft, thus preventing dry running
immediately after start up.
The face of the filter head assembly
shows the two concentric grooves, inlet
and outlet ports and the central threaded
recess for the main bolt.
The outer groove takes the filter body
seal. The inner groove contains the inlet
port, which delivers oil from the pump.
The hollow bolt above the inlet port takes
two banjo connections: 1. From the oil pump (within the
2. To the oil pressure gauge.
The banjo connection to the NRV
assembly takes oil via a long delivery pipe
and a series of banjo connections, to the
camshaft and then on to the forward main crankshaft bearing. The connection to the main
crankshaft bearing inlet also takes spill oil returning from the camshaft via the exhaust
manifold and a large bore pipe which runs from a connection on the underside of the
exhaust manifold to the double banjo connection for the forward main crankshaft bearing.
The oil pressure can be set by a screw and locknut arrangement located on the side of the cylinder
Cooling System
Exhaust System
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF