Volvo Penta D11-725 Specifications
| Engine Model: Volvo Penta D11-725 |
| Engine Type: 4-cycle inline 6-cylinder direct injection liquid-cooled diesel |
| Total Displacement: 661 cu.in (10.8 L) |
| Rated Engine Power: 725 Hp (537 kW) at 1800 rpm |
| Aspiration Type: Turbocharged and aftercooled |
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The Volvo Penta D11-725 is a heavy-duty,
six-cylinder, in-line diesel engine designed for high-performance
commercial and industrial applications. It delivers 725 Hp at 1800 RPM,
engineered for prime and continuous power generation, marine propulsion,
and demanding off-highway machinery.
This engine employs advanced combustion technology and a robust
construction to achieve a balance of high power output, operational
efficiency, and long-term durability. The design prioritizes
serviceability and features integrated electronic controls for optimized
performance and monitoring across varied operating conditions.
Engine Model: Volvo Penta D11-725.
Engine Type: Four-stroke, direct injection, turbocharged and aftercooled
diesel engine.
Number of Cylinders: 6, in-line.
Bore: 123 mm (4.84 inches).
Stroke: 152 mm (5.98 inches).
Displacement: 10.8 liters (661 cubic inches).
Compression Ratio: 17.0:1.
Aspiration: Turbocharged with charge air cooling (aftercooled).
Rated Power: 725 Hp (537 kW) at 1800 RPM.
Peak Torque: 3150 Nm at 1400 RPM. (2325 lb-ft).
Firing Order: 1-5-3-6-2-4.
Rotation (flywheel end): Counterclockwise.
Governor Type: Electronic, CAN J1939 compliant.
Emissions Compliance: Meets IMO Tier II, EU Stage IIIA, and U.S. EPA
Tier 3 standards for industrial engines.
The cylinder block is a rigid, one-piece cast iron construction. It
features a deep-skirt design that contributes to high torsional
stiffness and reduced vibration. Cylinder liners are replaceable, wet
type, made from centrifugally cast iron for superior wear resistance.
The block incorporates seven main bearings with generously sized bearing
caps, secured by four vertical bolts and two lateral cross-bolts per
cap. This cross-bolted main bearing design significantly increases block
strength and crankshaft stability under heavy loads. The oil and coolant
passages are cast integrally.
Each cylinder is fitted with an individual cylinder head, constructed
from cast iron. Each head houses two inlet and two exhaust valves. Valve
seats are hardened and integral for the inlet, with inserted hardened
seats for the exhaust valves. Valve guides are replaceable.
The engine uses overhead camshafts, with one camshaft operating the unit
injectors and a separate camshaft for the valve train. Valve stems are
equipped with rotary caps to promote even wear and seat conditioning.
Valve angles are 30 deg for inlet and 45 deg for exhaust.
The fuel system is a high-pressure unit injector (HPI) system. Each
cylinder has a dedicated electronic unit injector, combining pumping and
atomization in one component. Injection pressure reaches 1800 bar. The
system is managed by the Volvo Penta Engine Management System (EMS).
The fuel supply circuit includes a primary filter with a water separator
and a secondary fine filter. A mechanical lift pump feeds fuel from the
tank to the filters. A return line with a restriction orifice maintains
stable pressure in the rail. Fuel grade must comply with ISO 8217
DMA/DMB or EN 590 standards.
The lubrication system is a pressure-fed, full-flow filtration system
with a gear-type oil pump. Oil is drawn from a deep sump through a
suction strainer. It passes through a full-flow, replaceable spin-on oil
filter. A built-in bypass oil cooler regulates oil temperature.
The system lubricates main and connecting rod bearings, camshaft
bearings, the valve train, and provides pressurized oil to the piston
cooling jets. Engine oil capacity, including filters, is approximately
58 liters (15.3 U.S. gallons). Oil specifications must meet Volvo Penta
VDS-3 or equivalent ACEA E6/E7, API CJ-4.
The engine uses a dual-circuit cooling system. A high-temperature
circuit cools the cylinder block, cylinder heads, and oil cooler. A
separate low-temperature circuit cools the charge air aftercooler. Each
circuit is equipped with a centrifugal water pump, thermostatic control,
and a pressure relief cap.
The system is designed for use with a heat exchanger or remote radiator.
Coolant must be a mixture of 50% distilled water and 50% glycol-based
antifreeze with an additive package meeting Volvo Penta requirements.
Total coolant capacity is approximately 60 liters (15.9 U.S. gallons).
Starting System: A 24-volt electrical system with two heavy-duty
starters. Air intake system includes a dry-type, two-stage air filter
with a service indicator. Exhaust system is insulated and designed for
connection to a vertical or horizontal outlet.
The engine is equipped with a centrifugal crankcase ventilation
breather. Engine braking is available as an optional system. The wiring
harness is sealed and resistant to oil, fuel, and heat.
Length (from flywheel housing to front pulley): 1685 mm (66.3 inches).
Width (over valve cover): 1050 mm (41.3 inches).
Height (over intake manifold): 1280 mm (50.4 inches).
Dry Weight (engine only, without fluids): 1250 kg (2755 lbs).
Engine Oil Change Interval: 500 hours or 1 year under standard operating
conditions.
Oil Filter Change: Every oil change interval.
Fuel Filter Primary: Service every 250 hours. Replace element every 500
hours.
Fuel Filter Secondary: Replace every 500 hours.
Coolant Change Interval: 1000 hours or 4 years, with inhibitor checks
annually.
Air Filter: Replace as indicated by service gauge or per pressure
differential check. Inspect every 250 hours. Valve Clearance Adjustment
(cold setting): Inlet valve 0.40 mm (0.016 in). Exhaust valve 0.70 mm
(0.028 in). Check every 1000 hours.
Belt Tension: Check water pump and alternator belt tension every 250
hours. Adjust or replace as necessary.
Main Bearing Cap Bolts (M20): First pass 50 Nm, second pass 90 deg
rotation, final pass additional 90 deg rotation.
Cylinder Head Bolts (M16): First pass 50 Nm, second pass 90 deg
rotation, third pass additional 90 deg rotation.
Connecting Rod Cap Bolts (M14): First pass 30 Nm, final pass 120 deg
rotation.
Flywheel-to-Crankshaft Bolts (M16): 265 Nm. (195 lb-ft).
Vibration Damper Bolt: 450 Nm + 90 deg rotation. (332 lb-ft + 90 deg).
Injector Clamp Bolt: 35 Nm. (26 lb-ft).
Oil Pan Bolts (M10): 35 Nm. (26 lb-ft).
Exhaust Manifold Nuts (M10): 40 Nm. (30 lb-ft).
The Volvo Penta D11-725 is engineered for severe-duty applications.
Primary uses include high-capacity generator sets for prime and standby
power. In marine sectors, it serves as the propulsion engine for
commercial fishing vessels, fast ferries, and workboats.
For industrial machinery, this engine powers heavy-duty construction
equipment such as pile drivers, dredgers, and large mobile crushers. It
is also found in auxiliary power units for mining and oilfield
applications. The engine's power profile and torque characteristics make
it suited for equipment requiring constant high load factor operation.
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