Yanmar 6LY3 ETP Specifications
| Engine Model: Yanmar 6LY3 ETP |
| Engine Type: 4-stroke inline 6-cylinder turbocharged water-cooled diesel |
| Total Displacement: 354 cu.in (5.81 L) |
| Rated Engine Power: 480 Hp (353 kW) at 3300 rpm |
| Fuel System Type: Direct injection |
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The Yanmar 6LY3-ETP is a high-performance,
6-cylinder marine diesel engine that represents the first generation of
electronic management in the 6LY series. Manufactured by Yanmar Marine,
this engine features a 24-valve cylinder head and a direct injection
system controlled by an electronic governor, offering improved throttle
response and reduced emissions compared to earlier mechanical models.
The Yanmar 6LY3-ETP produces 480 Hp at 3300 rpm and is turbocharged with
a seawater-cooled intercooler. The engine incorporates the VC10
electronic control system, enabling drive-by-wire throttle and shift
operation as well as real-time fuel flow monitoring. This powerplant
meets EU RCD, US EPA Tier 2, BSO II, IMO Tier 2, and EMC emissions
standards.
The robust construction features a fresh water cooling system with heat
exchanger, utilizing a centrifugal pump for coolant circulation and a
rubber impeller seawater pump. The 6LY3-ETP is commonly paired with the
Yanmar KMH61A down-angle gearbox or ZF 85A marine transmissions, making
it suitable for planing and semi-displacement vessels including yachts,
sportfishing boats, catamarans, and light commercial workboats.
The Yanmar 6LY3-ETP is a 4-stroke, inline 6-cylinder diesel engine
designed for marine propulsion in high-performance vessels. The engine
architecture follows a conventional inline configuration with an evenly
spaced firing interval of 120 degrees. The bore and stroke dimensions
are nearly square, with a bore of 106 mm and a stroke of 110 mm,
promoting both torque development and high-rpm power delivery for
planing hull applications.
The engine features direct injection combustion with electronic
controlled injection, eliminating mechanical governors and providing
precise fuel metering across the operating range. The engine is
turbocharged and intercooled, with the seawater-cooled intercooler
reducing intake air temperature before entry to the intake manifold.
Engine Type: Inline 6-cylinder, 4-stroke diesel
Displacement: 5.813 L (354 cu.in)
Bore x Stroke: 106 mm x 110 mm (4.17 in x 4.33 in)
Compression Ratio: 18.3:1
Valvetrain: OHV, 4 valves per cylinder (24 valves total)
Combustion System: Direct injection, electronic controlled injection
Aspiration: Turbocharged with seawater-cooled intercooler
Cooling System: Fresh water cooling with heat exchanger, raw water
intercooler
Rotation Direction: Counterclockwise viewed from flywheel
Maximum Output (Pleasure Use): 353 kW (480 hp) @ 3,300 rpm
Continuous Rating (Commercial Use): 321 kW (436 hp) @ 3,200 rpm
Rated Speed: 3,300 rpm
Maximum Continuous Operating Speed: 2,800 rpm
Peak Torque: 1,260 Nm (929 lb-ft) @ 2,400 rpm
The cylinder block is constructed from high-strength cast iron,
providing the rigidity required for sustained marine diesel operation
with turbocharging. The block incorporates parent-bore cylinders
machined directly into the cast iron material. The block contains seven
main bearing bulkheads (one at each cylinder position plus front and
rear) to support the forged steel crankshaft. The crankcase is
reinforced around the main bearing areas to manage high combustion
pressures generated during direct injection operation.
Cast-in water jackets surround each cylinder bore, with coolant
circulation directed by the fresh water cooling system and heat
exchanger. The cylinder block is common across the 6LY3 series,
including the UTP (345 hp), STP (400 hp), and ETP (480 hp) variants. The
block incorporates mounting points for the turbocharger, intercooler,
heat exchanger, seawater pump, and transmission adapter. An oil pan
constructed from stamped steel forms the lower crankcase enclosure with
a drain plug at its lowest point.
Cylinder Configuration: Inline 6-cylinder
Cylinder Liner Type: Parent-bore (no replaceable liners)
The cylinder head is manufactured from cast iron using an overhead valve
(OHV) design with four valves per cylinder (24 valves total). The
four-valve configuration provides superior airflow compared to two-valve
designs, contributing to the engine's high specific output. The valve
actuation system consists of a camshaft located in the cylinder block,
mechanical lifters (tappets), pushrods, and forged steel rocker arms
mounted on a rocker shaft.
The camshaft is gear-driven from the crankshaft timing gear, eliminating
belt replacement intervals and improving reliability under marine duty
cycles. The valves are arranged in a cross-flow configuration with
intake valves on one side and exhaust valves on the opposite side. Valve
seats are pressed-in alloy steel rings, and valve guides are replaceable
units pressed into the head casting. The cylinder head incorporates the
direct injection fuel nozzle bores and the fresh water circulation
passages from the heat exchanger.
Valves per Cylinder: 4 (2 intake, 2 exhaust)
Total Valves: 24
Valve Arrangement: Overhead valve (OHV), pushrod actuated, cross-flow
The fuel system employs direct injection with electronic controlled
injection, representing the first generation of electronic management in
the 6LY series. The electronically controlled injection pump replaces
the mechanical governor of earlier engines with an electronic governor,
providing improved throttle response and real-time fuel flow monitoring
via the VC10 system.
The injection pump is mounted on the side of the cylinder block and
driven by the engine timing gear train. The electronic control unit
(ECU) manages injection timing and fuel delivery based on engine speed,
load, coolant temperature, and boost pressure. A fuel filter with
integral water separator is mounted on the engine.
Injection System: Direct injection, electronic controlled injection
Injection Pump Type: Electronic with hydraulic injection timer
Governor Type: Electronic, integrated into VC10 control system
Fuel Lift Pump: Mechanical, gear-driven
Fuel Temperature at Injection Pump Inlet: 40 °C (104 °F) per ISO 8665
The lubrication system is a full-pressure, forced-feed, enclosed design.
A gear-type oil pump, mounted within the timing gear cover and driven
directly from the crankshaft, draws oil from the oil pan through a
submerged strainer. The pump delivers oil under pressure to a full-flow
spin-on oil filter mounted on the engine block. A bypass valve allows
oil flow to the bearings if the filter becomes restricted. Filtered oil
is routed through a main oil gallery machined into the cylinder block.
Cross-drilled passages direct oil to the seven main bearings, with
drilled crankshaft passages feeding the connecting rod bearings. Oil is
routed upward through the cylinder block and cylinder head to lubricate
the camshaft and valve train components. An oil pressure relief valve
maintains system pressure. An optional lube oil evacuation pump is
available for simplified oil changes. An optional remote oil filter
mounting on the opposite side of the engine is also offered.
Oil Type: Diesel engine oil meeting Yanmar specifications (SAE 15W-40 or
SAE 30)
Oil Filter Type: Spin-on, full-flow
Oil Change Interval: 250 operating hours or annually (standard marine
practice)
Oil Cooler Type: Shell-and-tube, raw water-cooled
The cooling system is an indirect fresh water (coolant) cooling design
with a heat exchanger separating the internal fresh water circuit from
the external raw seawater circuit. A centrifugal fresh water circulating
pump, driven by a V-belt from the crankshaft pulley, circulates coolant
through the engine block and cylinder head. The heated coolant then
passes through a shell-and-tube heat exchanger where raw seawater
absorbs the heat before being discharged overboard.
A wax-pellet thermostat regulates coolant flow, maintaining engine
operating temperature between 76-88 °C (169-190 °F). A gear-driven
seawater pump with a rubber impeller is driven from the camshaft. The
intercooler is seawater-cooled, reducing intake air temperature after
turbocharging before air enters the intake manifold. The turbocharger is
also water-cooled for extended durability. An optional air vent for the
coolant tank is available.
Coolant Type: Ethylene glycol antifreeze with corrosion inhibitors
Heat Exchanger Type: Shell-and-tube, fresh water/raw water
Seawater Pump Type: Gear-driven, rubber impeller
Fresh Water Pump Type: Centrifugal, belt-driven
| Intake and Exhaust Systems |
Intake System: Air enters through a dry-type paper element air cleaner
mounted on the turbocharger intake. The turbocharger compresses incoming
air, which then passes through the seawater-cooled intercooler. The
intercooler reduces intake air temperature before air enters the intake
manifold. The intake manifold is a cast component with runners feeding
each cylinder.
Exhaust System: The exhaust manifold is a single-piece cast iron unit
with six ports merging into a single outlet for the turbocharger. A
standard L-type exhaust mixing elbow combines raw cooling water with
exhaust gases, reducing exhaust hose temperatures. An optional
high-riser mixing elbow is available for installations requiring
additional height to prevent seawater siphoning into the engine.
The engine is equipped with a 12-volt electrical system with a standard
alternator producing 120 amperes at 12 volts. A 24-volt 35 ampere
alternator is optional. The starter motor is a 12V, 3.0 kW unit. The
engine features the VC10 electronic control system, allowing
drive-by-wire throttle and shift operation. The system is NMEA 2000
compliant for integration with vessel electronics and displays. An air
heater is standard equipment for cold start assistance.
Turbocharger System: The 6LY3-ETP utilizes a water-cooled turbocharger
mounted directly to the exhaust manifold. The water-cooled bearing
housing extends turbocharger life under marine operating conditions.
Maximum boost pressure is not specified by manufacturer.
Control Systems: Classic (Hybrid) controls for mechanical backup and
Unlimited (Electronic) controls for full drive-by-wire operation are
available. A second station kit for flybridge installations is offered
as optional equipment. Various control heads, extension wire harnesses,
and a trolling mode kit are available as optional accessories.
Overall Length (including KMH61A gearbox and high-riser elbow): 1,458 mm
(57.4 in)
Overall Width: 907 mm (35.7 in)
Overall Height: 876 mm (34.5 in)
Length (engine only, without gearbox): 1,290 mm (50.8 in)
Width (engine only): 748 mm (29.4 in)
Height (engine only): 791 mm (31.1 in)
Dry Weight (without gear): 640 kg (1,411 lb)
Dry Weight (with gearbox): 650-666 kg (1,433-1,468 lb)
Wet Weight (with all fluids and gearbox): 680-700 kg (1,500-1,543 lb)
Engine Oil Change Interval: 250 operating hours or annually.
Total oil capacity is 18.0-22.0 L depending on the oil pan configuration
and filter.
Engine Oil Filter Change Interval: Replace with every oil change.
Fuel Filter Change Interval: 250 operating hours or annually.
Coolant Replacement Interval: 500 operating hours or 2 years.
Fresh water coolant capacity is 14.0-15.0 L depending on the heat
exchanger configuration.
Heat Exchanger Zinc Anode Inspection: Every 150-250 operating hours or 6
months.
Seawater Pump Impeller Replacement Interval: 250-500 operating hours or
annually.
Aftercooler Service Interval: Remove, disassemble, clean, grease, and
reassemble with new O-rings every 5 years.
Air Cleaner Inspection Interval: 250 operating hours.
Drive Belt Inspection Interval: Inspect every 250 hours; replace as
needed.
Rated Engine Speed (Maximum): 3,300 rpm.
Maximum Continuous Operating Speed: 2,800 rpm (recommended for extended
operation).
Recommended Cruising Speed Range: 2,500-2,800 rpm.
Cylinder Head Bolts, Stage 1: 40 Nm (30 lb-ft)
Cylinder Head Bolts, Stage 2: 130 Nm (96 lb-ft)
Connecting Rod Cap Bolts: 80 Nm (59 lb-ft)
Main Bearing Cap Bolts: 200 Nm (148 lb-ft)
Flywheel Bolts: 120 Nm (89 lb-ft)
Camshaft Bearing Cap Bolts: 25 Nm (18 lb-ft)
Rocker Arm Shaft Bolts: 30 Nm (22 lb-ft)
Intake Manifold Nuts: 25 Nm (18 lb-ft)
Exhaust Manifold Nuts: 50 Nm (37 lb-ft)
Injector Clamp Bolts: 35 Nm (26 lb-ft)
Glow Plugs: 20 Nm (15 lb-ft)
Oil Pan Bolts: 15 Nm (11 lb-ft)
Water Pump Bolts: 20 Nm (15 lb-ft)
Crankshaft Pulley Bolt: 450 Nm (332 lb-ft)
Turbocharger Mounting Nuts: 50 Nm (37 lb-ft)
The Yanmar 6LY3-ETP is engineered specifically for marine propulsion
applications requiring 480 horsepower. The engine is suitable for
planing and semi-displacement vessels where the flat torque curve from
2,100 rpm to 2,500 rpm provides excellent acceleration and cruising
efficiency.
Powerboat Applications:
Sportfishing Yachts: High-performance fishing vessels 11-14 m (36-46 ft)
requiring 30+ knot top speeds.
Express Cruisers: Fast cruising boats with single or twin engine
configurations.
Downeast Boats: Semi-displacement hulls operating at 15-25 knot cruise
speeds.
Catamaran Applications:
Power Catamarans: Vessel length 14.1 m (46.3 ft) with twin 6LY3-ETP
engines, shafts, and fixed pitch propellers; cruise speed 22 knots @
2,500 rpm; top speed 30 knots.
Twin-engine configuration: KMH61V-2 gears with 2.432:1 reduction ratio.
Commercial Applications:
Patrol Boats: Law enforcement and government vessels.
Work Boats: Pilot boats, water taxis, and light commercial vessels.
Charter Fishing Boats: Day charter and overnight sportfishing
operations.
Yacht Applications:
High-Performance Yachts: Vessels up to 18 m (60 ft) depending on hull
design and weight.
Pleasure Craft: Single or twin installations for cruising yachts and
motor yachts.
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