Nissan VK45DD Specifications
| Engine Model: Nissan VK45DD |
| Engine Type: 4-cycle 8-cylinder DOHC 32-valve VTC liquid-cooled gasoline |
| Total Displacement: 274.3 cu.in (4.49 L) |
| Rated Engine Power: 276 Hp (206 kW) at 6000 rpm |
| Fuel System Type: Direct injection gasoline |
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The Nissan VK45DD is a 4.5-liter, 90-degree V8 gasoline
engine produced from 2001 through 2010, representing the debut of Nissan’s VK
engine family. Engineered exclusively for the Japanese domestic market’s
flagship luxury sedans, the VK45DD was distinguished by its advanced direct
injection gasoline (DIG) system, marketed under the NEO Di designation. This
power unit succeeded the VH series V8 engines, introducing a suite of
technologies aimed at improving fuel efficiency, reducing emissions, and
enhancing low-end torque without sacrificing high-rpm power.
The engine’s aluminum construction, dual overhead camshaft (DOHC) valvetrain
with variable timing control (VTC), and a high 11.0:1 compression ratio set new
benchmarks for Nissan’s luxury powertrain offerings. Unlike the port-injected VH
engines that preceded it, the VK45DD utilized stratified charge combustion
enabled by direct injection, allowing for lean-burn operation under light loads.
The engine was installed exclusively in Nissan’s flagship Cima and President
models, where its emphasis on smoothness, silent operation, and responsive power
delivery aligned with the expectations of the luxury sedan segment.
The Nissan VK45DD is a four-stroke, water-cooled, 90-degree V8 gasoline engine
with a total displacement of 4,494 cc (274.3 cu.in). The bore and stroke
dimensions are 93.0 mm and 82.7 mm, respectively, creating an oversquare
configuration that favors high-rpm power while maintaining compact external
dimensions. The valvetrain employs a dual overhead camshaft (DOHC) design with
four valves per cylinder - two intake and two exhaust - for a total of 32
valves. Each cylinder head incorporates variable intake valve timing control
(VTC) on the intake camshafts, allowing the engine control unit to advance or
retard intake cam timing by up to 30 degrees based on engine speed and load.
The fuel system is a direct injection gasoline (DIG) system, branded as NEO Di,
with fuel injectors mounted directly in the cylinder head and delivering fuel at
high pressure into the combustion chamber. Induction is naturally aspirated
through a cast aluminum intake manifold with variable intake length
functionality.
The compression ratio is set at 11.0:1, a relatively high value for a naturally
aspirated V8 enabled by the charge-cooling effect of direct injection and the
knock-suppression capabilities of the engine management system.
Maximum power is rated at 206 kW (276 hp) at 6,000 rpm, adhering to the Japanese
manufacturer self-imposed output limit. Maximum torque is produced at 3,600 rpm,
with a rating of 451 Nm (333 lb-ft). The engine speed limiter is set at
approximately 6,500 rpm. The firing order is 1-8-4-3-6-5-7-2, a common
arrangement for cross-plane crankshaft V8 engines that provides balanced primary
and secondary forces.
The cylinder block is manufactured from aluminum alloy,
a material selected to reduce overall engine mass while maintaining structural
rigidity sufficient for a high-output V8. The block utilizes a 90-degree bank
angle, which provides a low center of gravity and balanced packaging for
longitudinal installation in luxury sedan chassis. The closed-deck design
incorporates cast iron cylinder liners pressed into the aluminum casting to
provide a durable wear surface for the aluminum pistons and steel piston rings.
The block features a deep-skirt construction, with the side walls extending
below the crankshaft centerline to enhance structural stiffness and reduce
noise, vibration, and harshness. The crankshaft is a forged steel unit with
eight counterweights, supported by five main bearings with micro-finished
journals to reduce friction. The main bearing caps are secured with four bolts
each, providing robust crankshaft support under the high cylinder pressures
generated by direct injection combustion. The block incorporates a water jacket
that surrounds the cylinders for effective heat transfer, with coolant flow
directed upward toward the cylinder heads.
Two separate cylinder heads, one for each bank, are
manufactured from aluminum alloy and feature a dual overhead camshaft (DOHC)
arrangement. Each cylinder head houses two camshafts - intake and exhaust -
supported by five bearing journals per camshaft, with micro-finished surfaces to
minimize frictional losses. The intake camshaft incorporates variable timing
control (VTC), utilizing a hydraulic actuator at the front of the camshaft to
adjust cam timing relative to the cam drive sprocket.
Valves are arranged in a pent-roof combustion chamber configuration with a
narrow included valve angle to promote efficient flame propagation and
accommodate the centrally located direct injector and spark plug. Intake valves
measure 34.0 mm (1.34 in) in diameter, while exhaust valves measure 29.0 mm
(1.14 in) in diameter. Valve actuation is provided by roller rocker arms that
reduce frictional losses compared to sliding designs.
Hydraulic lash adjusters are integrated into the cylinder head, maintaining zero
valve clearance throughout the engine’s operating life and eliminating the need
for periodic valve adjustment. The valve springs are of the single-coil type
with sufficient spring force to maintain valve control to the 6,500 rpm redline.
The combustion chamber is of the compact pent-roof design with the direct
injector positioned centrally and the spark plug located adjacent to the
injector to optimize fuel spray targeting and flame propagation.
The fuel system is a high-pressure direct injection
gasoline system, designated as NEO Di, operating at pressures up to 120 bar
(1,740 psi). A high-pressure fuel pump, mounted to the cylinder head and driven
by the intake camshaft, draws fuel from the in-tank electric pump and delivers
it through a high-pressure fuel rail to six-hole direct injectors mounted in
each cylinder head.
The injectors are solenoid-actuated and positioned to direct a precisely
targeted fuel spray into the combustion chamber during the compression stroke
under stratified charge operation or during the intake stroke under homogeneous
operation.
The engine control unit selects injection mode based on operating conditions.
Under light loads and low to medium engine speeds, the system operates in
stratified charge mode, injecting fuel late in the compression stroke to create
a combustible mixture only in the vicinity of the spark plug, allowing the
engine to operate with an extremely lean overall air-fuel ratio.
Under high loads and high engine speeds, the system operates in homogeneous
mode, injecting fuel during the intake stroke to create a uniform air-fuel
mixture for maximum power output. The fuel system also incorporates a returnless
design, with the fuel pressure regulator integrated into the high-pressure pump
to reduce fuel heating and evaporative emissions.
The lubrication system is a full-flow, pressurized
circuit utilizing a trochoid-type oil pump mounted within the front timing case
and driven directly by the crankshaft. The pump draws engine oil from a baffled
aluminum sump through a strainer screen before directing it through a full-flow
spin-on oil filter. An oil pressure relief valve maintains system pressure
within the specified range.
The main oil gallery distributes pressurized oil to the crankshaft main
bearings, connecting rod bearings, camshaft bearings, hydraulic lash adjusters,
and the variable valve timing actuators. Piston cooling is accomplished through
oil jets mounted in the crankcase, directing a continuous spray to the underside
of each piston crown to manage thermal loads under high-output operation.
The total engine oil capacity, including the filter, is 6.5 L (6.9 qt).
Recommended oil viscosity is 5W-30 or 5W-40, with synthetic formulations
specified to accommodate the high thermal loads and extended service intervals
of the luxury sedan application.
The cooling system operates as a pressurized,
thermostatically controlled water circulation circuit designed to manage the
thermal output of the high-compression V8. A belt-driven centrifugal water pump,
mounted to the front of the cylinder block, circulates a mixture of water and
ethylene glycol antifreeze through the cylinder block, cylinder heads, and the
main radiator.
The water pump features a high-flow impeller design to ensure adequate coolant
circulation through both cylinder banks. The thermostat is a wax-pellet type
positioned on the coolant inlet side of the water pump, maintaining operating
temperature within the range of 85C to 95C (185F to 203F). The radiator is a
cross-flow aluminum construction with plastic end tanks, sized to accommodate
the heat rejection requirements of the 4.5-liter V8.
An electric cooling fan, controlled by the engine control unit based on coolant
temperature and air conditioning compressor operation, provides forced airflow
during low-speed operation or high ambient temperatures. An expansion tank
allows for coolant expansion and provides a point for air separation from the
system. The total cooling system capacity is 9.5 L (10.0 qt) for the complete
system.
| Intake and Exhaust Systems |
Intake System: The intake manifold is constructed from
aluminum and features a dual-length variable induction system. A set of intake
valves within the manifold switches between long runners for low-end torque and
short runners for high-rpm power, with the changeover point determined by engine
speed and throttle position. The air intake system includes a large-capacity
dry-type paper air filter housed in a resonator-equipped air cleaner assembly to
minimize induction noise.
Exhaust System: The exhaust manifolds are constructed from stainless steel
tubular headers, designed to optimize exhaust gas flow to the catalytic
converters. Four heated oxygen sensors are positioned in the exhaust system -
two upstream and two downstream of the close-coupled catalytic converters -
providing feedback to the engine control unit for closed-loop fuel control and
catalyst monitoring.
Ignition System: The ignition system utilizes a
distributorless ignition system with individual ignition coils mounted directly
over each spark plug. The engine control unit determines ignition timing based
on inputs from the crankshaft position sensor, camshaft position sensors, and
knock sensors. The knock sensors allow the ECU to retard ignition timing under
detonation conditions to protect the engine while optimizing timing for maximum
power and efficiency under normal conditions. The spark plugs are long-life
platinum or iridium types with a gap of 1.0 mm (0.039 in) to 1.1 mm (0.043 in).
Timing Drive: The camshafts are driven by a silent-type timing chain
arrangement. A primary chain drives the intake camshaft of the right bank, with
secondary chains connecting the intake camshafts to the exhaust camshafts on
each bank. The timing chain is lubricated by engine oil and guided by tensioners
and guides, with hydraulic chain tensioners maintaining proper chain tension
throughout the engine’s operating life.
The overall length, measured from the front accessory
drive to the flywheel mating face, is 730 mm (28.7 in). Width across the
cylinder heads and intake manifold is 880 mm (34.6 in). Height from the bottom
of the oil sump to the top of the intake manifold is 710 mm (28.0 in).
The dry weight of the engine, inclusive of the
intake and exhaust manifolds, alternator, starter motor, and fuel system
components but without transmission or fluids, is 185 kg (408 lb),
reflecting the weight savings achieved through the aluminum block and
cylinder head construction.
The engine oil and filter must be replaced at intervals
not exceeding 10,000 km (6,214 mi) or 12 months under normal operation, using a
high-quality synthetic oil meeting Nissan specifications. The timing chain
requires no scheduled replacement but should be inspected for tensioner wear and
chain stretch at major service intervals. The spark plugs are long-life platinum
or iridium types with a replacement interval of 100,000 km (62,137 mi).
The air filter element should be inspected at each oil change and replaced every
30,000 km (18,641 mi) to 40,000 km (24,855 mi) depending on operating
conditions. The fuel filter is a high-pressure unit integrated with the fuel
pump assembly or mounted in-line, with a recommended service interval of 40,000
km (24,855 mi) to 60,000 km (37,282 mi).
Coolant replacement is specified at 40,000 km (24,855 mi) or every two years,
utilizing a long-life antifreeze formulation. The direct injection system
requires periodic inspection for carbon buildup on intake valves, a
characteristic of direct injection gasoline engines, with professional cleaning
recommended as required.
Cylinder Head Bolts: 30 Nm (22 lb-ft).
Main Bearing Cap Bolts: 40 Nm (30 lb-ft).
Connecting Rod Cap Bolts: 25 Nm (18 lb-ft).
Camshaft Bearing Caps: 12 Nm (9 lb-ft).
Flywheel Bolts: 110 Nm (81 lb-ft).
Crankshaft Pulley Bolt: 250 Nm (184 lb-ft).
Intake Manifold Bolts: 22 Nm (16 lb-ft).
Exhaust Manifold Nuts: 30 Nm (22 lb-ft).
High-Pressure Fuel Pump Mounting Bolts: 20 Nm (15 lb-ft).
Fuel Injector Clamp Bolts: 15 Nm (11 lb-ft).
Oil Pan Bolts: 12 Nm (9 lb-ft).
Timing Chain Tensioner Bolts: 25 Nm (18 lb-ft).
Spark Plugs: 25 Nm (18 lb-ft).
Engine Mounting Brackets: 60 Nm (44 lb-ft).
The Nissan VK45DD was produced exclusively for Nissan’s
flagship luxury sedan platforms in the Japanese domestic market, where its
combination of smooth power delivery, advanced direct injection technology, and
refined operation aligned with the expectations of the premium segment.
Nissan Cima (F50): The VK45DD served as the top-tier power unit for the fourth
generation Cima, a full-size luxury sedan positioned as Nissan’s flagship.
Produced from 2001 to 2010, the F50 Cima utilized the VK45DD in its highest
specification trims, where the engine’s direct injection technology provided the
fuel efficiency and low-end torque demanded by the luxury segment. The engine
was paired with a five-speed automatic transmission in rear-wheel drive and
all-wheel drive configurations.
Nissan President (PGF50): The President, Nissan’s ultimate luxury sedan and the
platform shared with the Cima, received the VK45DD as its exclusive power unit
from 2003 to 2010. Positioned as a chauffeur-driven limousine and executive
transport vehicle, the President demanded the highest levels of powertrain
refinement, silence, and smoothness.
The VK45DD’s direct injection system contributed to reduced fuel consumption
compared to the port-injected VH series, while its high compression ratio and
variable valve timing delivered the linear torque characteristics essential for
dignified performance in this application.
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