Honda A20A4 Specifications
| Engine Model: Honda A20A4 |
| Engine Type: 4-cycle inline 4-cylinder SOHC 16-valve liquid-cooled gasoline |
| Total Displacement: 119.3 cu.in (1.96 L) |
| Rated Engine Power: 110-120 Hp (82-89 kW) at 5500 rpm |
| Fuel System Type: Multi-point electronic fuel injection (PGM-FI) |
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The Honda A20A4 engine is a 2.0-liter inline
four-cylinder gasoline engine produced for the third-generation Honda
Accord during the late 1980s. As a member of Honda’s A-series family,
the A20A4 emphasized strong low-end torque, mechanical durability, and
smooth drivability while maintaining respectable fuel efficiency for its
era. This engine uses a single overhead camshaft configuration with 12
valves, a cast-iron block, aluminum cylinder head, and Honda’s
Programmed Fuel Injection (PGM-FI).
Known for its robustness, long service life,
and ease of maintenance, the A20A4 became especially appreciated for its
straightforward mechanical layout and reliability. Although predating
variable valve timing technologies, the engine delivers consistent
performance and remains highly regarded among classic Honda enthusiasts.
The Honda A20A4 is a four-stroke, water-cooled inline four-cylinder
gasoline engine with a displacement of 1,955 cc, equal to 119.3 cubic
inches. Bore measures 82.7 mm, or 3.26 inches, and stroke measures 91.0
mm, or 3.58 inches. This long-stroke geometry favors low-end torque and
smooth mid-range operation. The compression ratio varies slightly by
production year but commonly falls around 9.2:1.
Power output is approximately 110 to 120 horsepower, or about 82 to 89
kW, at roughly 5,300 to 5,500 rpm. Peak torque averages about 160 to 170
Nm, or 118 to 125 lb-ft, delivered at around 4,000 rpm. Idle speed is
typically 750 ± 50 rpm. The firing order is 1-3-4-2. Redline is
positioned near 6,300 rpm, with fuel cut slightly above it.
The cast-iron block contributes to the engine’s long service life.
Cylinder walls are precision-machined, enabling excellent ring sealing.
The crankshaft is a forged-steel component supported by five main
bearings. Pistons are cast aluminum alloy with three-ring
configurations, including two compression rings and one oil-control
ring. Connecting rods are forged steel, sized for longevity and stable
reciprocating mass characteristics.
The aluminum cylinder head is a SOHC design featuring three valves per
cylinder—two intake valves and one exhaust valve. This arrangement
provides moderate airflow with enhanced swirl and combustion stability.
Rocker arms are actuated by the camshaft, and
valve lash is adjusted manually by screw-and-locknut hardware. The
timing system uses a toothed rubber belt that drives both the camshaft
and the water pump. Timing belt replacement interval is approximately
90,000–100,000 km, or 55,000–62,000 miles.
The A20A4 uses Honda’s PGM-FI electronic fuel injection system. An
electric fuel pump mounted inside the fuel tank sends fuel through a
chassis-mounted filter before reaching the fuel rail. Fuel pressure is
regulated to approximately 36–42 psi, or about 250–290 kPa.
Injectors deliver fuel into each intake runner under ECU control. Fuel
metering depends on inputs including manifold-absolute-pressure
readings, throttle-position sensor data, engine-coolant-temperature
signals, intake-air-temperature sensor input, and oxygen-sensor
feedback. The system ensures stable idle, smooth acceleration, and good
fuel efficiency. Recommended fuel is unleaded gasoline with at least 87
AKI, or 91 RON.
Lubrication is provided by a full-pressure wet-sump system driven by a
crankshaft-mounted trochoid oil pump. Oil is drawn through a pickup
screen, pressurized by the pump, and routed through a full-flow spin-on
filter. The main oil gallery supplies crankshaft bearings,
connecting-rod journals, camshaft journals, rocker arms, and valvetrain
components.
Oil capacity including filter is approximately 4.0 to 4.3 liters, or 4.2
to 4.5 US quarts. Recommended oil viscosity is SAE 5W-30 or 10W-30
meeting API SG or higher. Typical oil pressure is 50–70 psi at cruising
rpm, with a minimum of 10 psi at idle. The PCV system maintains internal
crankcase ventilation and reduces combustion byproduct accumulation.
Cooling is provided by a belt-driven centrifugal water pump that
circulates coolant throughout the engine block, aluminum head, radiator,
and heater core. Thermostat opening begins at around 82°C, or 180°F, and
reaches full opening at roughly 95°C, or 203°F. Cooling-system capacity
is approximately 6.0 to 6.5 liters, or 6.3 to 6.9 US quarts.
Radiator cap pressure specification is 13–16 psi, or 90–110 kPa. A 50/50
mixture of ethylene glycol coolant and distilled water is recommended.
Coolant replacement intervals are typically every 40,000 km or two
years.
| Intake and Exhaust Systems |
The induction system consists of an air-cleaner housing with a
replaceable dry-element filter, an intake resonator for noise reduction,
and an aluminum intake manifold designed for balanced flow distribution.
The throttle body is cable-operated and contains sensors for throttle
position and idle-air control.
The exhaust system uses a cast-steel manifold designed for rapid warm-up
and steady flow characteristics. The manifold connects to a catalytic
converter, followed by a resonator and muffler tuned for noise control.
Emissions-control equipment includes EGR, PCV, and evaporative emissions
components.
| Ignition and Electrical System |
The ignition system uses an electronic distributor that incorporates an
internal ignition coil, igniter module, and reference pickups. The ECU
or ignition control module modifies timing advance based on rpm, load,
coolant temperature, and intake temperature. High-voltage spark is
transmitted through plug wires to each cylinder.
Recommended spark plugs are NGK or Denso equivalents with a gap of about
1.1 mm, or 0.043 inches. Replacement intervals vary from 20,000 to
30,000 km for copper plugs and up to 60,000 km for platinum types.
The electrical system operates on 12 volts. The alternator typically
outputs 70 to 80 amperes. The starter motor uses a reduction-gear
design. Battery capacity is generally between 45 and 60 amp-hours.
Ground straps maintain stable electronic operation.
Sensors feeding the ECU include MAP, TPS, IAT, ECT, and an oxygen
sensor. Distributor-mounted pickups provide crank-angle and cam-angle
signals. Wire harnesses are designed to withstand heat and vibration
common in the engine compartment.
Length: 640–680 mm (25.2–26.8 inches)
Width: 580–620 mm (22.8–24.4 inches)
Height: 660–710 mm (26.0–28.0 inches)
Dry weight is 145 to 165 kg, or 320 to 364 lbs, depending on accessories
and emissions configuration.
Routine service intervals include:
Oil and filter every 10,000 km (6,000 miles)
Air filter every 20,000 km (12,000 miles)
Spark plugs every 20,000–30,000 km (or up to 60,000 km for platinum)
Fuel filter every 40,000 km (25,000 miles)
Valve-clearance inspection every 40,000–50,000 km
Timing-belt replacement every 90,000–100,000 km (55,000–62,000 miles)
Coolant every 40,000 km or two years
Standard compression pressure for a healthy engine is typically 180–200
psi, or 1,240–1,380 kPa, with no more than 10% variation across
cylinders.
Cylinder head bolts: 75–80 Nm (55–59 lb-ft)
Main bearing caps: 60–70 Nm (44–52 lb-ft)
Connecting rod bolts: 38–45 Nm (28–33 lb-ft)
Camshaft-bearing caps: 12–14 Nm (9–10 lb-ft)
Flywheel bolts: 95–105 Nm (70–77 lb-ft)
Crankshaft pulley bolt: 140–150 Nm (103–111 lb-ft)
Intake manifold bolts: 22–25 Nm (16–18 lb-ft)
Exhaust manifold nuts: 28–32 Nm (21–24 lb-ft)
Spark plugs: 18 Nm (13 lb-ft)
Oil drain plug: 35 Nm (26 lb-ft)
The A20A4 engine was primarily used in the 1986–1989 Honda Accord,
particularly in fuel-injected European and North American trim levels.
Its strong mid-range torque, solid mechanical construction, and easy
serviceability made it well-suited for midsize passenger vehicles.
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