Honda K24A K24Z
Honda K24A engine (K24Z, K24W)
|Manufacturer||Honda Motor Company
|Also called||Honda K24
|Cylinder block alloy||Aluminum|
4 valves per cylinder
|Piston stroke, mm (inch)||99 (3.90)|
|Cylinder bore, mm (inch)||87 (3.43)|
|Displacement||2354 cc (143.7 cu in)
|Power output||120 kW (160 HP) at 6,000 rpm
124 kW (166 HP) at 5,800 rpm
130 kW (170 HP) at 6,000 rpm
132 kW (177 HP) at 6,500 rpm
138 kW (185 HP) at 6,400 rpm
140 kW (190 HP) at 7,000 rpm
150 kW (201 HP) at 6,800 rpm
153 kW (205 HP) at 7,000 rpm
154 kW (206 HP) at 6,800 rpm
|Torque output||220 Nm (162 lb·ft) at 3,600 rpm
220 Nm (162 lb·ft) at 4,000 rpm
220 Nm (162 lb·ft) at 4,300 rpm
224 Nm (165 lb·ft) at 4,400 rpm
245 Nm (181 lb·ft) at 4,500 rpm
220 Nm (162 lb·ft) at 4,400 rpm
240 Nm (180 lb·ft) at 3,800 rpm
236 Nm (174 lb·ft) at 4,400 rpm
247 Nm (182 lb·ft) at 3,900 rpm
|Redline||6,500 (K24A1, K24A8, K24Y1, K24Z1,K24Z4, K24Z5)
6,800 (K24A4, K24Z2)
7,100 (K24A2, K24Y2, K24Z3, K24Z6, K24Z7)
|HP per liter||68
|Weight, kg (lbs)||187 (412)
|Fuel consumption, L/100 km (mpg)
|Turbocharger|| Naturally aspirated
|Oil consumption , L/1000 km
(qt. per miles)
|up to 1.0
(1 qt. per 600 miles)
|Recommended engine oil||0W-20
|Engine oil capacity, L (qt.)||4.2 (4.4)
|Oil change interval, km (miles)||5,000-10,000
|Normal engine operating temperature, °C (F)||–|
|Engine lifespan, km (miles)
-No life span loss
|The engine is installed in||Honda Accord
Honda Civic Si
Second generation Honda CR-V was launched in 2001, and the largest engine was the 2.4-liter K24A. This engine was created based on K20A’s younger brother, and it replaced the old F23A.
K24A is based on an aluminum cylinder block with cast iron liners; its deck height is 231.7 mm. Inside the unit, they installed the 99 mm stroke crankshaft, the size of the pistons was increased to 87 mm, their height was 30 mm, the length of connecting rods was 152 mm.
Thanks to these changes, they managed to make a 2.4-liter K24A out of the 2-liter K20A.
The cylinder block is covered by a 16-valve i-VTEC DOHC head. Here the i-VTEC system works only for the intake camshaft, it has two cam lobes and is tuned for saving fuel and low exhaust emissions. The diameter of the intake valves is 35 mm, of exhaust valves – 30 mm, valve stem diameter is 5.5 mm.
There are no hydraulic tappets, so you have to adjust valves after every 24,000 miles of mileage.
K24A valve clearances are 0.21-0.25 mm for intake and 0.28-0.32 mm for exhaust.
A timing chain is used here with a decent service life; it can last for 120,000 miles of mileage.
The intake system uses a 2-stage PPA intake manifold to improve the torque at low and medium engine speeds.
The K24A firing order is 1-3-4-2. The size of the OEM fuel injectors is 270 cc. The size of the throttle body is 60 mm.
Beside the described first version of the K24A1, a lot of other K24 models were made. You will find differences below.
Since 2007, K24Z series was made, which was created to comply with the increasingly stringent environmental regulations.
Since 2013, production of the K24W Earth Dreams modification started, which was almost completely different from the K24A or K24Z. Here a new lightweight cylinder block is used with the new crankshaft now positioned with an 8 mm offset from the axis of the cylinders; a modified flywheel and lightweight pistons are also installed. A new head is created for the new cylinder block, but now its exhaust end is faced forward, and intake faces the back of the engine. This head got a direct injection system, new combustion chamber, the increased to 11.1 compression ratio, and a i-VTEC system for intake valves, which is triggered at 4,800 rpm.
Production of K24 engines continues today, but they are replaced by more compact turbocharged L15B engines.
Honda K24 engine modifications and differences
1. K24A1 is the first version of the engine described above. The power is 160 HP @ 6,000 rpm and the torque is 220 Nm @ 3,600 rpm, with the rev limit at 6,500 rpm. It was only installed in 2002-2006 Honda CR-V.
2. K24A2 is a sports version of the K24A1 engine, which quite substantially differed from it. It had a forged crankshaft and dual balance shafts, reinforced connecting rods, lightweight pistons and the compression ratio increased to 10.5. More aggressive camshafts, i-VTEC system for intake and exhaust camshaft with three cam lobes, a large throttle body, a 1-stage RBB intake manifold, 310 cc fuel injectors and a high flow exhaust system are also used. The i-VTEC is triggered at 6,000 rpm. The engine power is 200 HP. @ 6,000 rpm, and the torque is 225 Nm @ 4,500 rpm.
In 2006, the engine got a 80 mm air intake duct (instead of the 70 mm one), 64 mm throttle body (instead of the 60 mm one), 36 mm intake valves, a new intake camshaft, and a 2.25″ exhaust system (instead of 2″). As a result, the power increased to 205 HP @ 7,000 rpm and the torque is 231 Nm @ 4,500 rpm, with the rev limit at 7,200 rpm.
This model was only installed in 2006-2008 Acura TSX.
3. K24A3 is an analogue to K24A2 1st gen for Europe and Australia.
4. K24A4 is an analogue to K24A1, but it has new pistons, the 9.7 compression ratio, a 1-stage RAA intake manifold and slightly modified head ports. It used i-VTEC to the intake camshaft that could change duration by +/- 25° and is tuned for the low-end and mid-range torque. The size of the stock fuel injectors is 270 cc. The power is 160 HP @ 5,500 rpm, and the torque is 218 Nm @ 4,500 rpm, and the rev limiter is 6,800 rpm.
5. K24A8 is an analogue to K24A4, but for a different environmental standard. Here an RTB intake manifold is used, almost the same as in K24A4, and an electronic throttle body. The i-VTEC system is triggered at 2,400 rpm.
6. K24Z1 – this engine replaced the K24A1. It has a new 1-stage RTB intake manifold, an improved i-VTEC system, increased to 9.7 compression ratio, another oil pan, an electronic throttle body and a modified exhaust system. As a result, the power increased to 166 HP @ 5,800 rpm, and the torque is 218 Nm @ 4,200 rpm.
7. K24Z2 – this engine replaced the K24A8 that has increased compression ratio to 10.5, new fuel injectors, an R40 intake manifold and an integrated exhaust manifold, as well as configured i-VTEC. Its exhaust emission corresponds to higher standards. The power was 177 HP @ 6,500 rpm, and the torque was 224 Nm @ 4,300 rpm.
8. K24Z3 is an analogue to K24Z2, but with a high flow exhaust system. This increased the power up to 190 HP @ 7,000 rpm, and the torque is 220 Nm @ 4,400 rpm.
For 2009-2014 Acura TSX, they made an improved version, where a 31 mm exhaust valves are used, the i-VTEC system is slightly modified, and the compression ratio increased to 11. This added to engine power and it reached 201 HP @ 7,000 rpm, and the torque is 233 Nm @ 4,400 rpm.
9. K24Z4 is the engine that came to replace the K24Z1. The difference is in compliance with higher environmental standards.
10. K24Z5 is an analogue to K24Z2 for the Chinese market.
11. K24Z6 is an analogue to K24Z2 for 2010-2014 Honda CR-V.
12. K24Z7 is an analogue to K24Z3 (like in Acura TSX) for 2012-2015 Honda Civic Si and 2013-2015 Acura ILX.
13. K24Y1 is an analogue to K24Z6 for Honda CR-V created for the Thailand market. The power is reduced to 170 HP @ 6,600 rpm, and the torque is 220Nm @ 4,300 rpm.
14. K24Y2 is an analogue to 2012 K24Z6, but for Honda Crosstour.
15. K24W is an Earth Dreams engine, which is described in the beginning of the article. The engine power is 185 HP @ 6,400 rpm, and the torque is 245 Nm @ 3,900 rpm.
16. K24W4 is an analogue to K24W for Australia and Asia. It featured compression ratio decreased to 10.1. The power is 174 HP @ 6,200 rpm, and the torque is 225 Nm @ 4,000 rpm.
17. K24W7 is an analogue to K24W with a dual-stage intake manifold and compression ratio increased to 11.6. The power is 206 HP @ 6,800 rpm, and the torque is 247 Nm @ 3,900 rpm.
Honda K24A (K24Z, K24W) engine problems and malfunctions
The problems here are the same as in K20: rapid wear on the exhaust camshaft, possible leaks of engine oil, rough idle, and more. HERE you will learn about Honda K24 reliability in detail.
Engine noise during startup. This happens due to the use of improper engine oil or untimely replacement of engine oil, which deteriorates the VTC gear. The noise comes from the right side of the engine? Then you have to replace the VTC gear. Sometimes, the timing chain starts rattling, the reason is the same, it is non-serious attitude to the choice of or frequency of replacement of motor oil.
Any K24 engine has a head worse than that in K20A2, or JDM K20A Type R, or JDM K20A Euro R. Heads of K24A2 (Acura TSX) or K24A3 are almost the same as in K20A2, but they have inferior camshafts, valve springs, etc.
It is most advantageous to take any K24A cylinder block and buy a K20A2, a K20A Euro R, or a K20A Type R head for it. Buy ACL race bearings, CP high compression pistons (CR ~ 12.5), I-Beam rods, ARP head studs, an FD2 flywheel, a K20A2 oil pump, RDX 410cc fuel injectors, and a Hondata KPro ECU. These performance parts will let you get about 260 HP at the flywheel.
If you are not happy with 260 HP, before you install the K20A2 head on the K24 cylinder block, it makes sense to do head porting with installation of Supertech valve guides, springs and retainers, Supertech 35.5 mm intake valves, Supertech 30mm exhaust valves, Skunk2 Stage 3 cams and adjustable cam gears. To that, add a cold air intake system, a Skunk2 70 mm throttle body, a ported RBC intake manifold or an RRC manifold, a Hondata intake manifold gasket, a Toda 4-2-1 header, and a 2.5″ exhaust system.
These are the best mods for getting 300 HP at the flywheel.
HERE we told about turbocharger installation in K24A and supercharger kit installation in K24A. The procedure is shown on the example of K20A, but there is no much difference. K24A stock internals can withstand over 400 HP, maybe 500 HP, but driving at the limit is not too reliable. For getting more power, it is better to use low compression forged pistons.