Honda K20A engine (K20C, K20Z)
|Manufacturer||Honda Motor Company
|Also called||Honda K20
|Cylinder block alloy||Aluminum|
4 valves per cylinder
|Piston stroke, mm (inch)||86 (3.39)|
|Cylinder bore, mm (inch)||86 (3.39)|
|Displacement||1996 cc (121.8 cu in)
|Power output||110 kW (150 HP) at 6,500 rpm
116 kW (155 HP) at 6,500 rpm
118 kW (158 HP) at 6,500 rpm
120 kW (160 HP) at 6,500 rpm
147 kW (197 HP) at 7,800 rpm
150 kW (200 HP) at 7,400 rpm
150 kW (201 HP) at 7,800 rpm
160 kW (210 HP) at 7,800 rpm
158 kW (212 HP) at 8,000 rpm
162 kW (217 HP) at 8,000 rpm
165 kW (221 HP) at 8,000 rpm
188 kW (252 HP) at 6,500 rpm
203 kW (272 HP) at 6,500 rpm
228 kW (306 HP) at 6,500 rpm
|Torque output||190 Nm (140 lb·ft) at 4,500 rpm
177 Nm (131 lb·ft) at 5,000 rpm
190 Nm (140 lb·ft) at 4,000 rpm
179 Nm (132 lb·ft) at 4,000 rpm
188 Nm (139 lb·ft) at 6,200 rpm
193 Nm (142 lb·ft) at 6,000 rpm
193 Nm (142 lb·ft) at 6,800 rpm
194 Nm (143 lb·ft) at 6,200 rpm
202 Nm (149 lb·ft) at 7,000 rpm
206 Nm (152 lb·ft) at 7,000 rpm
215 Nm (159 lb·ft) at 6,100 rpm
370 Nm (273 lb·ft) at 1,500-4,000 rpm
370 Nm (273 lb·ft) at 1,500-4,000 rpm
400 Nm (295 lb·ft) at 2,500-4,500 rpm
7,000 (K20C Type R)
7,900 (RSX Type S)
8,000 (Civic Si/Type R, CSX Type S)
8,400 (Integra Type R)
|HP per liter||75
|Weight, kg (lbs)||184 (405)
|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) – K20A
|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 Integra/Acura RSX
In the end of 2000, production of JDM Honda Stream with the new K20A engine started. This engine replaced B16, B18, B20, H22, and F20, and it was the first in K series Honda engines. Later, this family included K23 and K24.
An inline-4 cylinder block made of aluminum was developed for K20A, its deck height was 212 mm. Inside the unit, they installed the 86 mm stroke crankshaft, the size of the pistons is also 86 mm, their height is 30 mm, the length of connecting rods is 139 mm. All this together provided 2 liters of displacement.
Some K20 versions were equipped with balance shafts.
The cylinder block is covered with a new DOHC head, to which the i-VTEC system is added that consisted of VTEC for intake valves, and VTC for intake and exhaust valves. It knows how to use the 12-valve mode to save fuel and the 16-valve mode in case of dynamic driving. The intake valves size is 35 mm, of exhaust valves – 30 mm, and valve stem diameter is 5.5 mm.
The camshafts are rotated by a timing chain with the service life longer than 120,000 miles of mileage.
Valves should to be adjusted after every 24,000 miles. Valve clearances for the cold engine are the following: intake 0.21-0.25 mm, exhaust 0.28-0.32 mm.
Here dual runner intake manifold and an EGR valve were used here for sending part of the exhaust gases back into the combustion chamber, which improves the ecological class of the vehicle. The K20A firing order is 1-3-4-2.
K20A engines were made in a wide variety of modifications and they were quite different. You can learn about the basic differences below.
In 2007, K20 was replaced with R20A engines. Today, only one version is made, K20C.
Honda K20 engine modifications and differences
1. K20A is a sports JDM version made since 2001. The engine power is 220 HP @ 8,000 rpm, the torque is 215 Nm @ 6,100 rpm.
Balancer shafts, a more rigid crankshaft, high compression pistons (CR = 11.5), reinforced connecting rods are installed into the cylinder block, and dual valve springs, dynamic camshafts, a lightened flywheel, a PRC intake manifold (an RBC intake manifold for Euro R), an improved header 4-2-1 and a 54 mm exhaust system are used. The size of standard fuel injectors is 310 cc.
The JDM K20A camshafts specifications are as follows: intake 244 (8.84)/280 (12.65)/245 (9.68), exhaust 240 (8.59)/278 (12.14)/244 (8.74).
Head porting is made for this engine at the factory. The size of the throttle body was 62 mm.
In 2007, the K20A engine received some upgrades. They installed a short RRC intake manifold, a 64 mm throttle body, improved the intake and exhaust head ports, installed reinforced connecting rods, and the compression ratio reached 11.7. Now the VTEC system is triggered at 5,800 rpm (instead of 6,000 rpm as before).
For 2007 JDM K20A, a 4-2-1 short header and a straighter 54 mm exhaust system are used. As a result, the power increased to 225 HP @ 8000 rpm, the torque is 215 Nm @ 6,100 rpm, and the rev limiter is triggered at 8,600 rpm.
This engine can be found only in JDM Civic Type R FD2.
2. K20A1 – this version was described in the beginning of the article. The power was 156 HP @ 6,500 rpm, and the torque was 188 Nm @ 4,000 rpm.
3. K20A2 is an analogue to JDM K20A, but it uses different camshafts and a PRB intake manifold. Here are the K20A2 cam specs: intake – 238 (7.36)/278 (12.42)/240 (7.82), exhaust – 240 (7.14)/280 (11.12)/242 (7.72). The compression ratio is slightly lower – 11, and the i-VTEC system is triggered at 5,800 rpm. The power was 201 HP @ 7,400 rpm, the torque is 193 Nm @ 6,000 rpm, and the rev limiter is triggered at 8,250 rpm. The size of OEM fuel injectors is 310 cc.
4. K20A3 is an analogue to K20A1 for 2002-2006 Acura RSX and 2002-2005 Honda Civic Si. The size of injectors is 270 cc, i-VTEC is triggered at 2,200 rpm. A PPA intake manifold is used here, which is triggered at 4,600 rpm. For Honda Civic Si, a 1-stage PRB intake manifold was used.
5. K20A4 is an analogue to K20A3 for USDM 2003-2007 Honda Accord and 2002-2006 Honda CR-V.
6. K20A6 is an analogue to K20A3 for the European and Australian 2003-2006 Honda Accord.
7. K20Z1 is a modified version of the K20A2 engine. Here they modified the intake system, used the same PRB intake manifold, a new exhaust manifold, and installed more dynamic camshafts, which resulted in 210 HP @ 7,800 rpm, and the torque was 194 Nm @ 6,200 rpm.
7. K20Z2 is a replacement for K20A, it featured a new long runner intake manifold, modified camshafts and the Drive by wire technology. The power was 155 HP @ 6,000 rpm, and the torque was 188 Nm @ 4,500 rpm.
8. K20Z3 is an analogue to K20Z1, but with different camshafts and an RRB intake manifold. The power was 197 HP @ 7,800 rpm, and the torque was 188 Nm @ 6,200 rpm. It was intended for 2006-2011 Honda Civic Si and 2007-2010 Acura CSX Type S.
9. K20Z4 is an analogue to K20Z3, but with an RSP intake manifold. It can be found in European 2007-2010 Civic Type R. The power was 201 HP @ 7,800 rpm, and the torque was 199 Nm @ 6,800 rpm.
10. K20C1 is a turbocharged version for 2015+ Honda Civic Type R. A new lightweight crankshaft, forged connecting rods, and modified pistons (compression ratio 9.8) are used here. In addition, a new cylinder head with direct injection system and i-VTEC system for intake and exhaust valves is used. The engineers improved the intake and exhaust head ports, and added a single-scroll MHI TD04 turbocharger. Boost pressure here is 23.2 PSI (1.58 bar).
All these upgrades were a success, and the engine reached 310 HP @ 6,500 rpm and the torque is 400 Nm @ 2,500 – 4,500 rpm, with the rev limit of 7,000 rpm.
11. K20C2 is a naturally aspirated version of the K20C for 2016+ Honda Civic. For this engine, a modified i-VTEC head with a direct injection system and improved combustion chambers is used. Similar to K20C1, a lightweight crankshaft and modified pistons (compression ratio 10.8) are used. The power of this engine is 158 HP @ 6,500 rpm, and the torque is 187 Nm @ 4,200 rpm.
12. K20C3 is an analogue to K20C1, but here the compression ratio was increased to 10.8 and a MHI TD03 turbocharger is used. The power is 272 HP @ 6,500 rpm, with the torque of 370 Nm @ 1,500 to 4,000 rpm.
13. K20C4 is an analogue to K20C1 with a MHI TD03 turbocharger. The boost pressure is 20.8 PSI (1.43 bar), the power is 252 HP @ 6,500 rpm, with the torque of 370 Nm @ 1,500 to 4,000 rpm.
Honda K20A (K20Z, K20C) engine problems and malfunctions
1. Knocking sound in the engine. It is probably time to adjust valves. If this is not done, increased wear of the exhaust camshaft begins. This is a typical disease of the K20 engine, the camshaft is to be checked and replaced if necessary. Excessive camshaft wear is caused by irregular replacement of motor oil and the use of motor oils not listed in the owner’s manual.
2. Oil leaks. Check the crankshaft front seal. It is a common problem, replacement will fix it.
3. Rough idle. Experience shows that it is enough to clean the throttle body or the idle air control valve.
4. Vibrations. Check engine mounts, the problem is there almost in all cases. Highly worn engines may have a problem with elongated timing chain.
The engines made between 2000 and 2003 had the nasty problem with the 4th cylinder overheating. Otherwise it is a reliable engine, but it is important to use high quality motor oil and good gasoline. Follow all Honda instructions, come for maintenance in time, and you engine will run for a long time. K20A service life exceeds 200,000 miles of mileage.
K20/K24 Frankenstein build
For owners of K20A1, K20A3, K20A4, K20A6 and K20Z2, it makes no sense to make performance tuning of their engines. You will have to replace almost the entire engine: the crankshaft, connecting rods, pistons, the entire head with the intake/exhaust system, and the ECU. It would be cheaper to buy a K20A Type R and swap.
If you own a JDM K20A, K20A2, K20Z1, K20Z3 and K20Z4, you are lucky and you can get a lot of power. Buy an RRC intake manifold, it is the best choice for high rpm of all OEM intake manifolds. You will need a FD2 throttle body, a cold air intake system, a 4-2-1 header, a 2.5″ exhaust system and a Hondata K-Pro ECU. Install these performance parts, tune the ECU and you will get up to 230 WHP. These are great upgrades for everyday use.
Want 250 HP? In this case, here are the best mods: a cold air intake, a Skunk2 70 mm throttle body, a Skunk2 intake manifold, Skunk2 Stage 2 cams, adjustable cam gears, Skunk2 valve springs and retainers, a 4-2-1 header, a 3″ exhaust system, a lightweight flywheel and RDX 410 cc fuel injectors.
You can go even further, and do head port and polish, install even more dynamic camshafts and get over 9,000 rpm.
It makes no sense playing with a 2-liter cylinder block, you’ve got too much already. Next you have to build a K20/K24 Frankenstein. You will need a K24A2 cylinder block and a JDM K20A or a K20A2 head. This will give you what you lacked previously, namely 2.4 liters of displacement.
Buy 87.5 mm Wiseco high compression pistons (or CP pistons) to increase the compression ratio to 12-13. Replace the OEM rods with Carillo I-Beam rods, and install a K20A2 oil pump, Skunk2 Stage 3 cams (or similar), adjustable cam gears, and a lightweight flywheel. You will need a 70 mm throttle body, a Skunk2 intake manifold, Skunk2 valve springs and retainers, a 4-2-1 header, a Walbro 255 lph fuel pump, Acura 410 cc fuel injectors and a Hondata KPro ECU. Here are the aftermarket parts that will let you get a naturally aspirated 300 HP engine. This is not the limit, you can go ahead with a sleeved block, a 2.7 liter stroker kit, individual throttle bodies, with the most dynamic camshafts, etc. The K20A engine can easily reach 10,000 rpm and more, but you will have to spend a small fortune on it.
The easiest way is buying a supercharger kit (Jackson Racing, Kraftwerks, or similar) that can boost the power to 300 HP with the boost pressure of 7-9 psi (0.5-0.6 bar).
K20A stock internals can withstand over 400 horsepower, but it is better to use forged internals to ensure high reliability. Buy low compression pistons (Wiseco/CP), Carillo H-beam rods, ACL bearings, and ARP head studs.
Make complete head porting, install a 800 cc fuel injectors, a Walbro 255 fuel pump, a 4-2-1 header, a 3″ exhaust system, and a KPro and Kraftwerk supercharger kit. These performance mods will give about 400 WHP or more.
You can install a Greddy turbo kit and get similar values. A Garrett GT3076R turbocharger with Skunk2 Stage 2 cams, Skunk2 valve springs and retainers will give you even more power.
Owners of Honda Civic Type R or Honda Accord 2.0 T engines are well off. Out of mods for K20C, you will need a cold air intake system, a front intercooler, a downpipe, a 3″ performance exhaust system, and Stage 2 chip tuning. This will give you up to 380 horsepower (280 HP for Accord X) with only the OEM turbocharger.