Nissan LD28 Specifications
| Engine Model: Nissan LD28 |
| Engine Type: 4-cycle inline 6-cylinder OHV 12-valve liquid-cooled diesel |
| Total Displacement: 172.4 cu.in (2.83 L) |
| Rated Engine Power: 80-95 Hp (56-69 kW) at 4000 rpm |
| Fuel System Type: Indirect fuel injection |
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The Nissan LD28 engine is a 2.8-liter,
inline-six, four-stroke, water-cooled diesel engine widely used in
Nissan’s passenger sedans, light trucks, vans, and industrial
applications. Introduced in the late 1970s and continuing into the 1980s
and 1990s in various markets, the LD28 belongs to Nissan’s LD-series of
durable indirect-injection diesel engines. It is known for excellent
mechanical longevity, smooth operation due to its six-cylinder
configuration, low fuel consumption, and the ability to tolerate
inconsistent fuel quality.
The LD28 combines a cast-iron block, cast-iron cylinder head, OHV
valvetrain, and a fully mechanical inline injection pump. These design
traits allow reliable operation with minimal electronic dependence. The
LD28 is prized in both automotive and marine conversions for its
robustness, stable operating temperatures, and high level of
serviceability.
The Nissan LD28 displaces approx. 2,826 cc (2.8 liters / 172.4 cubic
inches). Bore is approx. 84.5 mm (3.33 in), and stroke is approx. 83.0
mm (3.27 in). Compression ratio varies between 21.0:1 - 22.0:1 depending
on model and emissions requirements. The firing order is 1-5-3-6-2-4.
Idle speed is 700-750 rpm. Power output ranges approx. 80-95 hp at
around 4,000 rpm. Torque output is approx. 120-135 lb-ft (163-183 Nm) at
around 2,000 rpm.
The LD28’s straight-six architecture provides exceptional balance and
smoothness, reducing vibration levels. The cast-iron block uses seven
main bearings for maximum crankshaft stability. The crankshaft is forged
steel with fully machined journals. Pistons are cast aluminum alloy with
three-ring sets and reinforced crowns. Connecting rods are forged steel.
Indirect-injection combustion allows quieter operation, stable cold
starts, and improved emissions for the era.
The cylinder head is cast iron with two valves
per cylinder arranged in an OHV configuration. A block-mounted camshaft
drives valves through hardened pushrods and rocker arms. Valve lash is
manually adjustable using screw-and-locknut adjusters.
Pre-combustion chambers are cast into the head to support indirect
injection, creating swirl and efficient burn characteristics. The LD28
head is highly tolerant of heat stress when coolant maintenance is
performed.
Ports are arranged for consistent airflow. Intake ports encourage swirl,
improving mixture formation. Exhaust ports are short and robust,
dissipating heat efficiently. Glow plugs preheat the pre-combustion
chambers to ensure reliable cold starts.
The LD28 uses a fully mechanical diesel fuel system.
Major components include:
- Mechanical lift pump
- Fuel sediment bowl with water separator
- Primary and secondary fuel filters
- Inline high-pressure mechanical injection pump (Bosch-type)
- High-pressure steel injector lines
- Multi-hole diesel injectors
- Fuel-return line system
The mechanical governor regulates engine speed. Injection timing is
adjusted by rotating the injection pump on its mounting flange. The
injectors atomize fuel into pre-chambers for efficient burn. Fuel
quality has significant influence on injector life, making filter
maintenance crucial.
The LD28 employs a full-pressure wet-sump system.
Specifications:
- Oil capacity: approx. 6.0-7.0 liters (6.3-7.4 US qt)
- Normal oil pressure: approx. 45-65 psi at 3,000 rpm; approx. 15-20 psi
at idle
- Recommended oil: 15W-40 or 10W-30 diesel-rated (API CF-CH)
A crankshaft-driven trochoid oil pump supplies pressurized oil to
crankshaft bearings, connecting-rod bearings, camshaft bearings, and
valvetrain components. A full-flow replaceable spin-on oil filter cleans
the oil. Oil jets may cool the undersides of pistons on some variants.
Cooling is handled by a liquid-cooled system with a belt-driven
centrifugal water pump, thermostat, and radiator.
Specifications:
- Thermostat begins opening approx. 82°C (180°F)
- Thermostat fully open approx. 95°C (203°F)
- Cooling-system capacity: approx. 9.0-10.0 liters (9.5-10.5 US qt)
- System pressure: approx. 13-15 psi
The cooling system uses an expansion tank, heater core, bypass passages,
and internal cooling jackets. Regular coolant replacement helps prevent
scale buildup in the cast-iron block and head.
| Intake and Exhaust Systems |
The LD28 induction system includes:
- Heavy-duty air-cleaner housing
- Replaceable paper air-filter element
- Intake snorkel system
- Pre-heater for cold-weather use
Airflow is optimized for torque delivery at low rpm. Marine conversions
commonly adapt the induction system for water-separating filtration.
The LD28 uses a cast-iron exhaust manifold and a single downpipe.
Emissions-controlled variants may include:
- EGR valve
- Oxidation catalyst
- Closed crankcase ventilation
Marine variants may incorporate water-cooled exhaust manifolds.
The LD28 uses a 12-volt electrical system.
Components include:
- Alternator approx. 50-70 amps
- Reduction-gear starter motor
- Glow plugs
- Glow-plug relay and timing controller
- Heavy-duty battery approx. 70-100 Ah
Glow-plug activation is essential for cold-start performance.
- Length: approx. 740-780 mm (29.1-30.7 in)
- Width: approx. 600-650 mm (23.6-25.6 in)
- Height: approx. 700-750 mm (27.6-29.5 in)
Dry weight: 230-260 kg (507-573 lb) depending on accessories and
application
Recommended intervals:
- Oil and filter change: every 5,000-7,500 km (3,000-5,000 mi)
- Fuel filters: every 10,000-20,000 km
- Air-filter inspection: every 10,000 km; replace when needed
- Valve-lash adjustment: every 20,000-30,000 km
- Coolant replacement: every 2 years
- Glow-plug inspection: every 20,000 km
- Injection timing check: during major service
- Idle speed: approx. 700-750 rpm.
Compression readings:
- Approx. 380-460 psi
- Cylinder variation: less than 10 percent
- Cylinder-head bolts: 110-130 Nm (81-96 lb-ft)
- Main-bearing-cap bolts: 110-130 Nm (81-96 lb-ft)
- Connecting-rod bolts: 70-80 Nm (52-59 lb-ft)
- Flywheel bolts: 130-150 Nm (96-111 lb-ft)
- Intake-manifold bolts: 20-25 Nm (15-18 lb-ft)
- Exhaust-manifold nuts: 30-35 Nm (22-26 lb-ft)
- Injector hold-down bolts: 25-30 Nm (18-22 lb-ft)
- Oil-drain plug: 30-35 Nm (22-26 lb-ft)
The LD28 engine appeared in:
- Nissan Laurel (C31)
- Nissan Maxima (810 / early US models)
- Nissan Cedric / Gloria diesel variants
- Nissan Van and people-mover applications
- Industrial equipment and marine conversions (aftermarket)
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