The Honda K-series engine is a line of four-cylinder four-stroke car engines introduced in 2001. The K-series engines are equipped with DOHC valvetrains and use roller rockers on the cylinder head to reduce friction. The engines use a coil-on-plug, distributorless ignition system with a coil for each spark plug. This system forgoes the use of a conventional distributor-based ignition timing system in favor of a computer-controlled system that allows the ECU to control ignition timings based on various sensor inputs. The cylinders have cast iron sleeves similar to the B- and F-series engines, as opposed to the FRM cylinders found in the H- and newer F-series engines found only in the Honda S2000.

Similar to B series, the K-series car engines have two short blocks with the same design; the only difference between them being the deck height. K20 uses the short block with a deck height of where K23 and K24 block has a deck height of .

Two versions of the Honda i-VTEC system can be found on a K-series engine, and both versions can come with variable timing control (VTC) on the intake cam. The VTEC system on engines like the K20A3 only operate on the intake cam; at low rpm only one intake valve is fully opened, the other opening just slightly to create a swirl effect in the combustion chamber for improved fuel atomization. At high engine speeds, both intake valves open fully to improve engine breathing. In engines such as the K20A2 found in the Acura RSX Type-S, the VTEC system operates on both the intake and exhaust valves, allowing both to benefit from multiple cam profiles. A modified K20C engine is used in motorsport, as the Sports Car Club of America Formula 3 and 4 series that run in North America both use a K20C engine, with the Formula 4 engine not having a turbocharger.

Another significant difference between K-series engines is the alignment of the crankshaft to the center line of the bore. The K20C1 engine block has an offset alignment. Engines that do not have their crank shaft aligned to the bore are known as Desaxe engines. On the K20C1 engine this allows the power stroke to have more leverage and less thrust waste on sidewalls.

K-series engine swaps, also known as "K-swaps", have increasingly gained popularity in the import scene, but also among hot rodders and kit car enthusiasts, because they can be put in longitudinal rear-wheel drive layouts. __TOC__

K20 K20A (i-VTEC)

Applications Engine Application Compression Power Torque Redline Rev limiter i-VTECengagement IntakeManifold K20A(High Performance) 2001–2006 Honda Civic Type R (JDM) 11.5:1 at 8000 rpm at 7000 rpm 8400 rpm 6000 rpm PRC 2001–2006 Honda Integra Type R (JDM) 11.5:1 at 8000 rpm at 7000 rpm 8400 rpm 8600 rpm 6000 rpm PRC 2002–2008 Honda Accord Euro R (JDM) 11.5:1 at 8000 rpm at 6000 rpm8400 rpm 8600 rpm 6000 rpm RBC 2007–2011 Honda Civic Type R (JDM) 11.7:1 at 8000 rpm at 6100 rpm 8400 rpm 8600 rpm 5800 rpm RRC K20A (Eco) 2000–2006 Honda Stream (JDM) (RN3, FWD) 9.7:1 at 6500 rpm at 4000 rpm 6800 rpm PNC 2000–2006 Honda Stream (JDM) (RN4, AWD) 9.8:1 at 6500 rpm at 4000 rpm 6800 rpm 7000 PNC 2001–2004 Honda CR-V (JDM) 9.8:1 at 6500 rpm at 4000 rpm 6800 rpm PNA 2001–2006 Honda Integra Type S (JDM) 9.8:1 at 6500 rpm at 4000 rpm 6800 rpm PNC 2001–2005 Honda Stepwgn (JDM) 9.8:1 at 6500 rpm at 4000 rpm 6800 rpm PNC 2001–2005 Honda Stepwgn Spada (JDM) 9.7:1 at 6500 rpm at 4000 rpm 6800 rpm PNC 2005–2009 Honda Stepwgn (JDM) 9.6:1 at 6000 rpm at 4500 rpm 6800 rpm RTA 2002–2008 Honda Accord (JDM) (CL7-CM1, FWD) 9.8:1 at 6000 rpm at 4500 rpm 6800 rpm RAA 2002–2008 Honda Accord (JDM) (CL8, AWD) 9.8:1 at 6000 rpm at 4500 rpm 6800 rpm RAA 2004–2009 Honda Edix (JDM) 9.7:1 at 6500 rpm at 4000 rpm 6800 rpm PNC 2005–2010 Honda Civic (JDM) 9.6:1 at 6000 rpm at 4500 rpm 6800 rpm RTB K20A1 2001–2006 Honda Stream (RN3, FWD) 9.7:1 at 6500 rpm at 4000 rpm 6800 rpm PNA 2001–2006 Honda Stream (RN4, AWD) 9.8:1 at 6500 rpm at 4000 rpm 6800 rpm PNC K20A2 2001–2006 Honda Civic Type R () 11.0:1 at 7400 rpm at 5900 rpm 7900 rpm 8250 rpm 5800 rpm PRB 2002–2004 Acura RSX Type S 11.0:1 at 7400 rpm at 6000 rpm 7900 rpm 8250 rpm 5800 rpm PRB 2002–2004 Honda Integra Type R (/) 11.0:1 at 7400 rpm at 6000 rpm 7800 rpm 8100 rpm 5800 rpm K20A3 2002–2006 Acura RSX 9.8:1 at 6500 rpm at 4000 rpm 6800 rpm7000 rpm 2300 rpm PNC 2002–2005 Honda Civic 9.8:1 at 6500 rpm at 4000 rpm 6800 rpm 7000 rpm 2300 rpm PRB 2002–2005 Honda Civic Si USDM 9.8:1 at 6500 rpm at 4000 rpm 6800 rpm 7000 rpm 2300 rpm PRB 2002–2005 Honda Civic Type S EDM 9.8:1 at 6500 rpm at 4000 rpm 6800 rpm 7100 rpm 2200 rpm PRB 2003–2006 Honda Civic 2.0 i-VTEC () 9.8:1 at 6500 rpm at 5000 rpm 6800 rpm 7000 rpm PRB K20A4 2002–2006 Honda CR-V 9.8:1 at 6500 rpm at 4000 rpm 6800 rpm PNA K20A6 2003–2006 Honda Accord () 9.8:1 at 6500 rpm at 4000 rpm 6800 rpm 2500 rpm RAA 2003–2006 Honda Accord () 9.8:1 at 6500 rpm at 4000 rpm 6800 rpm 2500 rpm RAA K20A7 2003–2007 Honda Accord (SEA) 9.8:1 at 6000 rpm at 4500 rpm 6800 rpm RAAK20A92004–2007 Honda FR-V ()9.8:1 at 6500 rpm at 4000 rpm6800 rpm2500 rpm PNC

Additional notes K20A Spec R engine (FD2 Civic Type R) Chromoly flywheel, higher-tensile strength connecting rods, high-compression pistons, stiffer valve springs, higher-lift hollow camshafts with more duration, and 2007–2011 cylinder-head intake-port and exhaust-port surface polishing used in NSX-R. The JDM K20A type-R engine block would be removed from production assembly line by an experienced Honda engine technician to torque the connecting rod bolts to factory specification by hand using micrometer to measure connecting rod bolt stretching. Then the JDM K20A type-R engine block would be returned to the production assembly line to complete the engine building process.

K20B (i-VTEC I)

Injection Pressure: Center Fuel Injection with swirl guide Air-Fuel Ratio: Normal driving cycle: 65:1 (ultra-lean combustion) Acceleration/High load driving cycle: 14.7:1 (Stoichiometric) Deep Piston Cavity formed in top of Pistons Intake Manifold code: PPD Application: 2003–2006 Honda Stream Absolute

K20Z (i-VTEC)

Applications Engine Application Compression Power Torque Redline Rev limiter i-VTECengagement IntakeManifold K20Z1 2005–2006 Acura RSX Type S 11.0:1 at 7800 rpm at 6200 rpm 8100 rpm 8300 rpm 5800 rpm PRB 2005–2006 Honda Integra Type S (/) 11.0:1 at 7800 rpm at 6200 rpm 8100 rpm 8300 rpm 5800 rpm K20Z2 2006–2011 Acura CSX 9.8:1 at 6000 rpm at 4500 rpm 6800 rpm 2006–2008 Honda Accord () 9.8:1 at 6000 rpm at 4500 rpm 6800 rpm RBA 2006–2010 Honda Civic (SEA) 9.8:1 at 6000 rpm at 4500 rpm 6800 rpm RTB K20Z3 2006–2011 Honda Civic Si 11.0:1 at 7800 rpm at 6200 rpm 8000 rpm 8300 rpm 5800 rpm RBC 2007–2010 Acura CSX Type S 11.0:1 at 7800 rpm at 6200 rpm 8000 rpm 8300 rpm 5800 rpm K20Z4 2007–2010 Honda Civic Type R () 11.0:1 at 7800 rpm at 5600 rpm 8000 rpm 8200 rpm 5400 rpm RSP K20Z5 2007–2010 Honda Civic Si () 11.0:1 at 7800 rpm at 6800 rpm 8000 rpm 8200 rpm 5400 rpm

Additional notes K20Z3 (as fitted to Ariel's Atom 3.5) The K20Z3 has Honda's traditional performance VTEC on the intake and the exhaust cams, as found on previous generation of engines. Variable cam timing technology is included on the intake but not the exhaust cams. The added timing control corresponds to the "i" in i-VTEC.

K20C (Earth Dreams VTEC Turbo)

Applications Engine Application Compression Power Torque Redline Rev limiter i-VTECengagement K20C1 2015–2017 Honda Civic Type R (EDM)2017–2021 Honda Civic Type R (USDM)2018–present Ariel Atom 4 2023–present Honda Civic Type R (USDM) Formula Regional Americas Championship 9.8:1 at 6500 rpm at 2500–4000 rpm 7000 rpm 7000 rpm K20C3 2016–2023 Honda Avancier/UR-V (China) 9.8:1 at 6500 rpm at 4200 rpm 6100 rpm K20C4 2018–2022 Honda Accord (Sport, EX-L & Touring 2.0T trims) 9.8:1 at 6500 rpm at 1500–4000 rpm 6800 rpm 2019–present Acura RDX 9.8:1 at 6500 rpm at 1600–4500 rpm 6800 rpmK20C52019–present Acura RDX (China)9.8:1265 hp (195 kW) at 6500 rpm at 3000–4000 rpm6800 rpmK20C62021–2025 Acura TLX9.8:1272 hp (203 kW) at 6500 rpm at 1600–4500 rpm6800 rpmK20C72023–present Honda Avancier/UR-V (China, facelift models)9.8:1261 hp (192 kW) at 6,500 rpm273 lb⋅ft (370 N⋅m) at 2,250–3,500 rpm K20C8 2024–present Acura Integra Type S 9.8:1 at 6500 rpm at 2600–4000 rpm 7000 rpm

Additional notes

Earth Dreams Technology K20C1: First Honda Type R engine to be built in the US at the Honda Anna Engine Plant in Anna, Ohio. First time Honda has used a turbocharger on the Type R. K20C5: All Acura RDX sold in China (manufactured by GAC Acura) Although the K20C4 in the Acura RDX and the K20C6 in the Acura TLX share the same internals, they are named differently due to different engine mount points to accommodate the sedan body of the TLX. The VTEC mechanism is available only on the exhaust valves. K20C1 engines have an offset of 8mm on the crankshaft from the centerline of the bore. K20C8 (Acura Integra Type S): Engine is identical to the K20C1, it is named differently to accommodate different mounting points. K20C7: Based on K20C3, but detuned to meet Chinese VI-b regulations

K20C & K20Z (Earth Dreams i-VTEC)

Applications Engine Application Compression Power Torque Redline Rev limiter i-VTECengagement K20C2 2016–2018 Honda Civic (LX & EX) Sedan (USDM) 2019–2024 Honda Civic (LX & Sport) Sedan (USDM)

2016–2020 Honda Civic (LX, LX-P, Sport) Coupe (USDM)

2022–2024 Honda Civic (LX, Sport) Hatchback (USDM) 10.8:1 at 6500 rpm at 4200 rpm 6700 rpm 7000 rpm 6100 rpm (Manual)6500 rpm (CVT) 2016–2023 Formula 4 United States Championship 10.8:1 at 6500 rpm at 4200 rpm 6800 rpm 7000 rpm 6100 rpm K20C9 2025–present Honda Civic (LX & Sport) (USDM) 13.0:1 at 6400 rpm at 4000–5000 rpm 6700 rpm K20Z5 2023–present Honda HR-V (USDM) 10.8:1 at 6500 rpm at 4200 rpm 6800 rpm

Additional notes The K20C9 is a Dual VTC Atkinson cycle engine and uses direct injection.

K23 K23A (i-VTEC Turbo)

Applications Engine Application Compression Power Torque Redline Rev limiter i-VTECengagement IntakeManifold K23A1 2007–2012 Acura RDX 8.8:1 at 6000 rpm at 4500 rpm 6800 rpm 6900 rpm 2500 rpm

Additional notes This version of the K engine uses a Mitsubishi TD04HL-15T turbocharger with a dual path turbine housing, optimizing low end response while allowing better high end flow. Maximum boost pressure is 13.5psi. The engine includes i-VTEC and VTC technologies and comes mated to a version of Honda's 5-speed automatic with SH-AWD (note: SH-AWD was standard from 2007–2009 and optional from 2010–2012).

K24 K24A (i-VTEC)