Nissan CD20 Specifications
| Engine Model: Nissan CD20 |
| Engine Type: 4-cycle inline 4-cylinder SOHC 8-valve liquid-cooled diesel |
| Total Displacement: 119.5 cu.in (1.97 L) |
| Rated Engine Power: 75-79 Hp (55-59 kW) at 4800 rpm |
| Fuel System Type: Indirect fuel injection |
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The Nissan CD20 engine is a 2.0 liter inline
four-cylinder diesel powerplant developed as part of Nissan's CD series
of small displacement compression ignition engines. Introduced during
the early 1990s, the CD20 was engineered to provide excellent fuel
economy, long service life, and low running cost for compact and mid
size vehicles. It features indirect injection, a cast iron cylinder
block, aluminum alloy cylinder head, single overhead camshaft design,
and a mechanically controlled fuel injection pump.
The CD20 gained a solid reputation for durability under varied operating
conditions, including harsh climates and lower fuel quality markets. The
engine was widely used in passenger cars, small vans, and utility
vehicles such as the Nissan Sunny, Bluebird, Avenir, AD Van, and
Wingroad. Its modest power output is balanced by excellent fuel
consumption, making it suitable for long distance commuting and
commercial use.
The CD20 engine emphasizes simplicity and reliability. Its indirect
injection system provides smooth combustion and reduced noise compared
to older diesel engines. Although not a high-performance design, the
CD20 delivers dependable torque at low to mid-range engine speeds. The
engine's conservative compression ratio, simple mechanical injection
system, and robust construction allow long service intervals and high
mileage longevity. The CD20 helped Nissan compete in global diesel
markets by offering a refined and practical engine suited for everyday
use.
The displacement of the CD20 is 1973 cc. It has a bore of 84.5 mm or
3.33 inches and a stroke of 88.0 mm or 3.46 inches. This relatively long
stroke indicates a torque-oriented design suitable for diesel
combustion. The compression ratio is approximately 22.0 to 1. The firing
order is 1-3-4-2. The cycle is the conventional four stroke diesel cycle
with intake, compression, power, and exhaust events. The crankshaft is
supported by five main bearings for improved rigidity and smooth
rotation. Pistons are cast aluminum with reinforced crowns to withstand
high compression temperatures. Each piston uses two compression rings
and an oil control ring. Connecting rods are forged steel with full
floating gudgeon pins.
Maximum power output is typically between 75 and 79 Hp at around 4800
rpm depending on year and emission calibration. Maximum torque is 96 to
100 lb-ft or 130 to 135 Nm at about 2400 rpm. Idle speed is usually
around 750 rpm. The engine redline is modest for a diesel, at roughly
5000 rpm. The cylinder head design uses a precombustion chamber system
for indirect injection, resulting in smooth operation and quieter
combustion compared to direct injection engines of the same era.
The block is made from cast iron providing rigidity and long wear life.
Coolant passages are cast around the cylinders for uniform heat
distribution. The aluminum cylinder head contains the precombustion
chambers, intake ports, exhaust ports, and the single overhead camshaft
bearings. Valves are actuated by rocker arms controlled by the camshaft.
Valve seats are hardened for durability under diesel combustion
temperatures.
The CD20 engine uses a mechanically operated fuel injection system with
an inline or distributor type injection pump depending on model year and
vehicle application. Fuel is drawn from the tank by a mechanical lift
pump or an electric priming pump in some versions. The fuel then passes
through a primary filter and a secondary fine filter before entering the
injection pump.
Fuel pressure is generated by the injection pump, which meters and times
injection for each cylinder through high pressure metal lines. Injectors
are pintle type designed for indirect injection combustion chambers.
Injection pressure is typically in the range of 130 to 150 bar.
The injection pump includes mechanical governors to regulate fuel
delivery, cold start devices for improved starting at low temperature,
and timing adjustment mechanisms. Fuel return lines route excess fuel
back to the tank. Fuel filter replacement is critical to maintain
injector performance. The CD20 is tolerant of a variety of diesel fuel
grades but cleanliness is essential to protect the precision components
of the injection system.
The CD20 uses a full pressure wet sump lubrication system. A trochoid
oil pump driven by the crankshaft draws oil through a pickup screen and
delivers it through the main oil gallery. Oil is routed to main
bearings, connecting rod journals, camshaft bearings, and rocker arms.
The system incorporates a full flow replaceable oil filter. Oil jets
beneath the pistons spray oil onto the piston crowns for cooling. Normal
oil pressure at 3000 rpm is around 45 to 55 psi, and idle pressure is
around 10 to 15 psi. Oil capacity is approximately 4.0 liters or 4.2 US
quarts including filter.
Recommended oil viscosity is SAE 10W-30 or 15W-40 depending on climate.
Diesel rated oils meeting API CF or higher specifications are required
for proper soot suspension and wear protection. Oil and filter changes
should occur at intervals of about 5000 km or 3000 miles under mixed
driving.
The cooling system is a pressurized liquid cooling design using a belt
driven centrifugal water pump. Coolant circulates through block and head
passages, radiator, and heater core. The thermostat begins to open
around 82 C or 180 deg F and is fully open near 95 C or 203 deg F.
System capacity is roughly 6.5 to 7.0 liters or 6.8 to 7.4 US quarts.
The radiator cap maintains system pressure around 13 psi.
Radiator construction is aluminum core with plastic tanks. An engine
driven fan or electric fan ensures adequate airflow. Coolant mixture
should be a 50 50 blend of ethylene glycol and water. Regular coolant
replacement every two years protects aluminum components from corrosion.
Temperature sensors on some versions provide input for glow plug timing
and dashboard indication.
| Intake and Exhaust Systems |
The induction system consists of an air cleaner housing with a
replaceable paper element, intake ducting, and intake manifold. The
intake manifold is cast aluminum or cast iron depending on model. Some
versions include a cold air intake flap to improve starting.
The exhaust system uses a heavy-duty cast iron manifold connected to a
downpipe and catalytic converter on emission certified variants.
Naturally aspirated versions of the CD20 do not use a turbocharger.
Exhaust gas recirculation is present on some engines for emission
reduction.
The electrical system includes an alternator rated around 70 to 80
amperes, a starter motor capable of high torque cranking, glow plug
wiring, sensors for coolant temperature, oil pressure, and some models
include crank angle sensors for improved emission control. Battery
capacity is 60 to 70 amp-hours to support glow plug operation.
Diesel engines require preheating for reliable cold starts. The CD20
uses sheathed type glow plugs installed in the precombustion chambers. A
glow control relay and timer unit manage preheat duration based on
coolant temperature. The glow time ranges from 3 to 8 seconds in mild
climates and longer in colder regions. Afterglow operation may continue
for a short period after starting to improve idle stability.
| Valve Train and Timing Belt |
The single overhead camshaft is driven by a rubber toothed timing belt.
The belt also drives the water pump in some versions. Valve actuation is
via rocker arms and pivot adjustment screws. Valve clearance must be
checked and adjusted periodically. Intake and exhaust valves are
arranged in a crossflow pattern for efficient breathing. Timing belt
replacement is recommended at about 100000 km or 60000 miles. Belt
tension is controlled by a spring-loaded tensioner.
The engine features a positive crankcase ventilation system that
recycles blow by gases into the intake. The evaporative control system
is minimal on diesel engines but some versions include a separator or
catch tank for oil mist. Some variants include EGR valves for emission
control. The cooling system includes an expansion reservoir for thermal
expansion. Engine mounts use rubber isolators tuned to reduce diesel
vibration.
The CD20 engine is compact for a diesel design. Overall length is around
600 mm or 23.6 inches. Width is about 550 mm or 21.6 inches. Height is
around 650 mm or 25.6 inches. Dry weight is approximately 150 to 160 kg
or 330 to 352 lbs depending on accessories. The cast iron block
contributes to durability and vibration damping.
Oil change interval is every 5000 km or 3000 miles. Air filter
replacement is recommended every 20000 km or 12000 miles. Fuel filter
replacement should occur every 20000 to 30000 km depending on fuel
quality. Glow plugs should be inspected every major service interval.
Timing belt replacement at 100000 km is critical for reliability. Valve
clearance should be checked every 40000 km or 25000 miles.
Normal compression pressure for the CD20 is around 420 to 460 psi with a
minimum service limit near 350 psi. Cylinders should not vary more than
10 percent. Idle speed is adjusted at the injection pump to maintain
around 750 rpm. Injection timing must be set according to service
specifications using timing marks and a dial gauge or timing light for
diesel pumps. Cooling system maintenance includes periodic flushing and
thermostat inspection.
Cylinder head bolts require staged tightening to approximately 108 Nm or
80 lb-ft. Main bearing cap bolts torque to around 85 Nm or 63 lb-ft.
Connecting rod bolts torque to about 45 Nm or 33 lb-ft. Flywheel bolts
require around 100 Nm or 74 lb-ft. Intake manifold bolts torque to about
25 Nm or 18 lb-ft. Exhaust manifold nuts require around 35 Nm or 26
lb-ft. Glow plugs tighten to approximately 15 Nm or 11 lb-ft. Oil drain
plug torque is about 35 Nm or 26 lb-ft.
The CD20 engine was used in a variety of Nissan vehicles. These include
the Nissan Sunny models such as the B13 and B14 series, Nissan Bluebird
series including U12 and U13, Nissan Avenir and Primera in certain
diesel markets, and utility vehicles such as the AD Van, Wingroad, and
small commercial vans. The engine offered a balance of economy,
reliability, and adequate performance for daily transportation and light
duty commercial needs.
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