Amazingly no other manufacturer of small
marine diesel engines has this feature.
The 3YM30AE has the same gear-
driven camshaft and push rods to drive
the overhead valves and an all cast-iron
construction. Like the 3YM30, heat
exchanger cooling is standard.
The raw saltwater cooling pump is
gear-driven and the freshwater circulating
pump by the same v-belt that drives the
125 amp voltage regulated alternator
mounted high up on the engine. Even the
1.4kW starter motor is mounted well above
the engine bearers.
Complete with KM2P-1 gearbox, which
weighs only ten kilograms, the 3YM30AE
is 715 millimetres long, 486mm wide and
619mm high. If you are repowering from
a 3YM30 the additional width may mean
reshaping of the engine box. But there
should be no issues with mating the engine
up to the prop shaft drive f lange.
A sump evacuation pump is standard and
I recommend changing the oil and filter every
100 running hours or annually. For cooler
climates, such as around Tassie, a mineral-
based SAE10W30 oil would enable oil to
reach the rockers faster on cold mornings.
But for tropical climates an SAE15W40
would provide better engine protection.
Standard instrumentation includes an
analogue tachometer with digital engine
hours display plus switches for the ignition
and glow plugs. Plus, of course, audible
alarms for low engine oil pressure and
high coolant temperature.
FINAL WORDS
Sure Yanmar parts can be pricey
compared to other manufacturers but the
amount of detail that has gone into the
3YM30AE ref lects Yanmar's heritage of
making small marine diesels for well over
29
http://www.mysailing.com.auSimple and reliable
a thing of beauty.SPECIFICATIONS
OUTPUT AND FUEL FLOW
Engine type: three cylinder indirect injection naturally aspirated diesel
Maximum output: 28.6 brake horsepower at 3200rpm*
Maximum torque: 79 Newton metres at 1800rpm
Piston displacement: 1266cc
Dry weight
+ KM2P-1 gearbox: 137kg
+ SD25 sail drive: 157kg.As the 3YM30AE has mechanical injection
I recommend not running it continuously
below 1600rpm or above 2800rpm.
The engine should be worked to prevent
possible cylinder bore glazing from fuel
over-supply at lower revs and when
engine load is light.RPMMax,
torque
(NM)BHP
absorbed
by propActual
lph1400 73 3.1 1.1
1600 77 3.4 1.5
1800 79 5.4 1.9
2000 76 9.4 2.4
2200 73 11.0 3.0
2400 72 14.7 3.7
2600 70 18.5 4.6
2800 67 23.2 5.9
3000 65 24.8 6.5
3200 64 28.6 7.3Note the rapid torque rise at low revs
as expected from an industrial diesel,
but even at my recommended maximum
cruising revs of 2800, 85% of peak torque
is still available. This is very useful for
powering into head seas.Andrew Norton has written for
Cruising Helmsman since 1983.
He served in the Australian Merchant Navy where
he studied navigation and marine engineering and
later naval architecture at Sydney TAFE. He acquired
his first boat 51 years ago and has been sailing for
45 years. He lives in the Lake Macquarie NSW area.AUTHOR NAME HERE
40 years. There are still niggling issues,
such as exhaust manifolds rusting out,
but show me a manufacturer that does not
have some design and engineering issues.
The only real issue I have with all
of these indirect injection tractor and
industrial diesels is that there are no
hand starting facilities, relying instead
on starter motors and healthy starting
batteries. I well remember the hand start
Lister lifeboat and fire pump diesels
from one to three cylinders we had in the
merchant navy, where a combination of
relatively low compression direct injection,
decompression levers and hefty f lywheels
allowed for total mechanical ops.
Of course these engines were way
too dirty for current exhaust emissions
standards and as most small marine
diesels have industrial/tractor bases
designed for low emissions it stands to
reason something had to go.
This gripe aside modern engines like
the 3YM30AE are damned fine pieces of
engineering and with regular maintenance
and routine servicing should provide
thousands of hours of motoring pleasure.
Plus the heat exchangers allow for hot
water take-offs for on board showers,
something we all aspire to in modern
cruising yachts.
In my opinion, an easily-started and
reliable diesel makes a yacht complete.
http://www.power.equipment.com.au ≈