Honda K24A1 Specifications
| Engine Model: Honda K24A1 |
| Engine Type: 4-cycle inline 4-cylinder DOHC 16-valve i-VTEC liquid-cooled gasoline |
| Total Displacement: 143.6 cu.in (2.35 L) |
| Rated Engine Power: 160 Hp (119 kW) at 5500 rpm |
| Fuel System Type: Multi-point programmed fuel injection (PGM-FI) |
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The Honda K24A1 is a 2.4-liter inline-four
gasoline engine belonging to Honda’s first-generation K-series family.
Introduced in the early 2000s, the K24A1 powered vehicles such as the
Honda CR-V and Honda Accord, serving as a high-reliability,
high-efficiency alternative to the smaller K20 engines. Honda developed
the K24A1 to provide abundant low-to-mid-range torque, smooth operation,
and excellent long-term durability.
Unlike performance-focused versions such as the K24A2 or the K20A2, the
K24A1 is tuned conservatively, emphasizing stability, efficiency, and
drivability. It uses a DOHC layout with Honda’s i-VTEC system on the
intake camshaft, variable cam phasing, and a long-stroke design ideal
for usable real-world torque. Many owners report that the K24A1 easily
exceeds high mileage milestones with minimal internal wear, making it a
popular engine in both OEM and swap applications.
The K24A1 is a four-stroke, liquid-cooled inline-four gasoline engine
with a displacement of 2,354 cc (143.6 cubic inches). Bore is 87.0 mm
(3.43 inches), stroke is 99.0 mm (3.90 inches), creating a long-stroke
geometry that favors torque. The compression ratio ranges between 9.6:1
and 9.7:1 depending on market and calibration.
Factory output is 160 Hp (119 kW) at 5,500 rpm and around 220-221 Nm
(162-163 lb-ft) of torque at 3,600-4,000 rpm. Idle speed is set around
700-750 rpm, with a rev limiter near 6,500-6,800 rpm. The firing order
is 1-3-4-2. Internally, the K24A1 uses a forged steel crankshaft, forged
connecting rods, and lightweight aluminum pistons with molybdenum-coated
skirts. The crankshaft is supported by five main bearings designed for
long life.
The cylinder block is cast aluminum with cast-iron cylinder liners
integrated using Honda’s FRM (Fiber Reinforced Metal) or ductile-iron
liner technology (market-dependent). The long-stroke design supports
low-rpm torque and steady power delivery.
Deep-skirt block construction increases rigidity and reduces vibration.
The block’s coolant passages promote uniform cylinder cooling, improving
thermal stability and gasket life. Oil passages deliver lubrication to
main bearings, rod journals, and valvetrain components.
The aluminum DOHC cylinder head includes four valves per cylinder. Valve
sizes are approximately 35 mm for intake and 30 mm for exhaust. Roller
rocker arms reduce friction, while i-VTEC provides optimized lift and
duration on the intake camshaft.
The high-flow intake ports promote good volumetric efficiency, while the
combustion chambers support clean and stable combustion. The
chain-driven camshafts use a hydraulic tensioner for durability.
Fuel delivery is handled by Honda’s PGM-FI sequential multi-point
injection. Fuel pressure is controlled by an in-tank regulator at
approximately 350-400 kPa (51-58 psi). High-precision injectors deliver
atomized fuel to each cylinder.
Sensors include MAP, MAF (vehicle-dependent), TPS, IAT, ECT, upstream
O2, downstream O2, knock sensor, and CKP/CMP sensors. The ECU uses these
inputs to regulate timing, fuel mixture, VTEC operation, and idle
stability.
The lubrication system is a full-pressure wet-sump type with a
crank-driven trochoid oil pump. Oil capacity is 4.4 liters (4.6 US
quarts). Oil pressure at 3,000 rpm ranges from 350-500 kPa (51-72 psi).
Idle pressure is around 70-120 kPa (10-17 psi). A full-flow oil filter
captures contaminants. Recommended viscosity is 5W-20 or 5W-30 depending
on climate.
The cooling system uses a belt-driven centrifugal water pump and a
closed-loop coolant pathway. Coolant capacity is 6.7 liters (7.1 US
quarts). The thermostat begins opening between 78-82°C (172-180°F) and
is fully open near 95°C (203°F). The system pressure ranges from 88-110
kPa (13-16 psi).
| Intake and Exhaust Systems |
The induction system features a composite intake manifold designed for
low- and mid-range torque. The throttle body is 60-62 mm depending on
year, with drive-by-wire on later models.
The exhaust system uses a stainless manifold, close-coupled catalytic
converter, and secondary catalytic converter (vehicle-dependent).
Exhaust port geometry provides efficient scavenging while maintaining
emissions compliance.
| Ignition and Electrical System |
Ignition uses coil-on-plug modules with ECU-controlled timing. Spark
plug gap is 1.0-1.1 mm (0.039-0.043 in). Alternator output is around
90-110 A. Starter output is around 1.0-1.2 kW. The ECU manages fuel
control, timing, idle speed, VTEC activation, and knock response.
Length: 690 mm (27.2 in)
Width: 610 mm (24.0 in)
Height: 690 mm (27.2 in)
Dry weight: approx. 150-160 kg (330-353 lb)
Oil and filter: 8,000-10,000 km
Air filter: 20,000-30,000 km
Spark plugs: 100,000 km
Coolant: 40,000 km
Valve adjust: inspect at 160,000 km
Compression: 180-210 psi
Head bolts: 30 Nm + 90° + 90°
Main caps: 60 Nm
Rod bolts: 40 Nm + 90°
Flywheel: 88 Nm
Crank pulley: 245 Nm
Intake: 22 Nm
Exhaust: 30 Nm
Drain plug: 40 Nm
Spark plugs: 18 Nm
Honda CR-V (2002-2006), Honda Accord (market), various swaps.
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