Editing Honda C engine

{{more citations needed|date=April 2019}}
{{Infobox automobile engine
|name=Honda C engine
|image=Honda C30A engine 001.jpg
|manufacturer=[[Honda]]
|production=1985–2005
|configuration=90° [[V6 engine|V6]]
|block=[[Aluminum]]
|head=[[Aluminum]]
|displacement={{convert|1996|cc|L|1|abbr=on|order=flip}}<br/>{{convert|2494|cc|L|1|abbr=on|order=flip}}<br/>{{convert|2675|cc|L|1|abbr=on|order=flip}}<br/>{{convert|2977|cc|L|1|abbr=on|order=flip}}<br/>{{convert|3179|cc|L|1|abbr=on|order=flip}}<br/>{{convert|3473|cc|L|1|abbr=on|order=flip}}
|bore={{convert|82|mm|2|abbr=on}}<br/>{{convert|84|mm|2|abbr=on}}<br/>{{convert|87|mm|2|abbr=on}}<br/>{{convert|90|mm|2|abbr=on}}<br/>{{convert|93|mm|2|abbr=on}}
|stroke={{convert|63|mm|2|abbr=on}}<br/>{{convert|75|mm|2|abbr=on}}<br/>{{convert|78|mm|2|abbr=on}}<br/>{{convert|91|mm|2|abbr=on}}
|valvetrain=[[SOHC]] & [[DOHC]] [[Multi-valve#Four valves|4 valves]] x cyl. ([[VTEC]] only in DOHC engines)
|turbocharger=[[Variable geometry turbocharger|Variable geometry]] (some versions)
|power=From {{convert|145|–|294|PS|kW bhp|0|abbr=on}}
|torque=From {{convert|17|–|32|kgm|0|abbr=on|order=flip}}
|management=[[Electronic Control Unit]]
|compression= 9.0:1, 9.6:1, 10.2:1
|fueltype=[[Gasoline]]
|fuelsystem=[[Fuel injection]]
|coolingsystem=[[Radiator (engine cooling)|Water-cooled]]
|successor=[[Honda J engine]]
}}

[[Honda]]'s first production V6 was the C series; it was produced in displacements from 2.0 to 3.5 liters. The C engine was produced in various forms for over 20 years (1985–2005), having first been used in the [[Honda Legend|KA series Legend]] model, and its British sister car the [[Rover 800|Rover 800-series]] (and [[Sterling (marque)|Sterling]]).

All C engines share in common a 90-degree V-angle from bank to bank, common cylinder block bore centers, and four valves per cylinder. It is an all-aluminum design, and uses timing belt-driven single or dual overhead camshafts; the water pump is also driven by the timing belt.

All C engines use an interference design; if the timing belt fails, any open valves will clash into the pistons, and severe engine damage will occur.

The engine family can be broken down into three sub families:
* C20A, C20AT, C25A and C27A (transversely mounted)
* C30A and C32B  (transversely mounted rear)
* C32A, C35A, and C35B (one-off) (longitudinally mounted)

As a general rule, interchange of parts will not work between these sub groups.

==C20A==

[[SOHC]] {{convert|1996|cc|L|1|abbr=on}}
* {{convert|145|PS|kW hp|0|abbr=on}} at 6,500 rpm
* {{convert|17|kgm|0|abbr=on|order=flip}} at 5,500 rpm

Japan only;

* 1986–1988 [[Honda Legend#KA1|Honda Legend]]
* Experimental [[Honda NSX (first generation)#Development|HP-X]] ('''H'''onda '''P'''ininfarina '''X'''perimental)

The [[variable length intake manifold]] used six individual small-bore intake runners below 3,500 rpm for each cylinder and added an additional six individual larger bore intake runners at higher RPMs.

The '''C20AT''' was a [[turbocharged]] version, called the "Wing Turbo", producing {{convert|190|bhp|kW PS|0|abbr=on}}.

Japan only:
* 1989 [[Honda Legend#KA1|Honda Legend]]

Honda replaced the variable length [[intake manifold]] with a [[variable geometry turbocharger]] to the C20A engine used in the [[Japanese Domestic Market]] Legend. The turbo with [[intercooler]]-equipped engine was the C20AT engine and are extremely rare. Honda pioneered variable-geometry turbo chargers. The "Wing Turbo", as Honda called them, were controlled by an 8-bit processor [[Electronic Control Unit|ECU]] and they were constantly adjusting. Basically, at low speeds the wings surrounding the turbine wheel inside the compressor housing on the intake side would be nearly closed to speed and direct exhaust pressure precisely on the turbine wheel. At 2000 rpm, the wings would fluctuate and it would act like a much larger turbo to increase [[Fuel economy in automobiles|fuel economy]] as needed. This car was quick and powerful, but the price premium over the slightly longer and wider Legend with the {{convert|2675|cc|L|1|abbr=on|order=flip}} [[naturally aspirated]] V6 was too much for most, so the car disappeared. This was one of the only production Hondas ever turbocharged from the factory (excluding turbo engines of [[kei car]] for the Japan domestic market), along with the [[Honda K engine#K23A1|K23A1]] straight-4 engine used in the [[Acura RDX]] and the [[Honda E engine#ER|ER]] [[straight-4 engine]] used in the first generation [[Honda City]] until model year 2017, when most of their model lines had the option of the 1.5L [[turbocharged]] engine.

==C25A==

[[SOHC]] (2.5 L) V6 24 valves, 9.0:1 compression

Japan
* {{convert|165|PS|kW hp|0|abbr=on}} at 6,000 rpm
* {{convert|21.5|kgm|0|abbr=on|order=flip}} at 4,500 rpm

North America
*{{convert|151|bhp|kW PS|0|abbr=on}} at 5,800 rpm
*{{convert|21.7|kgm|0|abbr=on|order=flip}} at 4,500 rpm

Applications:
* 1986-1987 [[Honda Legend]] 
* 1986-1987 [[Acura Legend]]
* 1986-1988 [[Rover 825]] 
* 1987-1988 [[Sterling (car)|Sterling 825i]]

The engine utilized a 90 degree V-angle to the crankshaft in preference to the taller but more common 60 degree design, with a compression ratio of 9.0:1. The [[crankshaft]] had crankpins offset 30 degrees to provide a low profile engine that fires smoothly and evenly. The block and cross flow [[Pent-roof combustion chamber|pent roof]] [[cylinder head]]s with 24 valves are [[Die casting|die-cast]] from [[aluminum alloy]] and the [[cylinder bore]]s are lined with [[cast iron]]. The [[exhaust system]] uses equal length [[exhaust pipe]]s connected to the [[Exhaust manifold]] to minimize scavenging resistance and maximum total exhaust efficiency. An external high capacity water cooled oil cooler and filter maintain an efficient oil temperature.

==C27A==

The [[SOHC]] '''C27A''' is a 2.7&nbsp;L version, with the major upgrade being the addition of a [[variable length intake manifold]], producing up to {{convert|132|kW|PS bhp|0|abbr=on}}

Applications; non-North America:

* C27A2 - 1988-1990 [[Honda Legend]] Coupe, {{convert|176|bhp|kW PS|0|abbr=on}} (non catalyst) UK and Europe
* C27A2 - 1988-1990 [[Honda Legend]] Saloon, {{convert|176|bhp|kW PS|0|abbr=on}} (non catalyst) UK and Europe
* C27A2 - 1987-1991 [[Rover 800|Rover 827/Sterling/Vitesse]], {{convert|177|bhp|kW PS|0|abbr=on}} (non catalyst) UK and Europe
* C27A1 - 1991 [[Rover 800|Rover 827/Sterling/Vitesse]], {{convert|168|bhp|kW PS|0|abbr=on}} (catalyst) UK and Europe 
* C27A1 - 1991-1995 [[Rover 800|Rover 827/Sterling/Coupe]], {{convert|168|bhp|kW PS|0|abbr=on}} (catalyst) UK and Europe

Applications; North America:

* C27A1 - 1987-1990 [[Acura Legend]] Coupe, {{cvt|161|bhp|kW PS|0}} (catalyst) 
* C27A1 - 1988-1990 [[Acura Legend]], {{cvt|161|bhp|kW PS|0}} (catalyst)
* C27A1 - 1988-1991 [[Sterling (marque)|Sterling 827]], {{cvt|168|bhp|kW PS|0}} (catalyst)
* C27A4 - 1995-1997 [[Honda Accord]], {{cvt|170|bhp|kW PS|0}} (catalyst) For this particular vehicle the engine was updated with a more efficient intake manifold.

==C30A==
The [[DOHC]] [[VTEC]] '''C30A''' is a {{convert|2977|cc|L|1|abbr=on}} version, producing {{convert|270|bhp|PS kW|0|abbr=on}} at 7,300 rpm and {{convert|29|kgm|0|abbr=on|order=flip}} of [[Torque#Machine torque|torque]] at 6,500 rpm, with a 10.2:1 compression ratio. The engine has a bore and stroke of 90mm x 78mm, making the engine highly over square, which facilitates a shift in power to the higher end of the rpm range. It utilizes a crankshaft with offset [[Crankpin|crankpins]] to achieve an evenly spaced firing interval of 120°, something typically unattainable with a 90° cylinder bank angle. Honda selected the 90° [[V6 engine|V6]] as the NSX's optimal engine choice, striking a balance between packaging, complexity, and lowering the car's [[Center of mass|center of gravity]]. The engine was the second Honda engine ever to utilize Honda's proprietary VTEC [[variable valve timing]] system in an automotive application after the B16A, which adjusts cam lift depending on engine [[revolutions per minute|RPM]] and [[throttle]] position. VTEC allows the C30A to produce a high maximum power level while maintaining a relatively flat torque curve. C30A was also equipped with [[Variable-length intake manifold|Variable Volume Induction System (VVIS)]], which used a primary and a secondary intake plenum. Secondary intake plenum engages at 4800 RPM to improve engines breathing ability and broadens torque curve.<ref>{{Cite web |url=http://www.jdmspecengines.com/honda-engines/honda-c-series/c30a.html |title=JDM Spec Engines - Honda C30A Engine |access-date=2012-12-07 |archive-date=2011-06-11 |archive-url=https://web.archive.org/web/20110611081711/http://www.jdmspecengines.com/honda-engines/honda-c-series/c30a.html |url-status=usurped }}</ref>

The C30A also made use of titanium [[connecting rods]], which was another first in a mass-production vehicle. The lightweight rods allowed a higher RPM to be achieved while maintaining the strength of traditional steel rods. The C30A block is an open-deck design made from an aluminum alloy with cylinders [[Cylinder (engine)#Cylinder sleeving|sleeved]] in ductile iron. The heads are [[Multi-valve#Four-valve cylinder head|4 valves]] per [[Cylinder (engine)|cylinder]] (24 valves per engine total), twin-cam design and contain the VTEC mechanism, which is actuated by oil pressure. For maximum performance, the C30A uses a [[direct ignition]] system, with individual [[ignition coil|ignition coils]] positioned directly over each cylinder [[spark plug]].

With its [[DOHC]] layout and its lightweight rotating assembly, the C30A is capable of reliable high RPM operation, but due to its complexity, cost, and use of exotic materials, the C30A was used exclusively on Honda's [[Honda NSX|NSX]] car. For NSXs equipped with a 4-speed automatic transmission, Honda used a slightly less powerful version of the C30A, with less aggressive [[Cam (mechanism)|cam]] timing and producing {{Convert|252|bhp|kW PS|0|abbr=on}}.

Though never mass produced, a heavily upgraded version of the engine was briefly used in GT-spec NSXs for the 2004 [[All Japan Grand Touring Car Championship|JGTC racing series]] by the [[:ja:Team Honda Racing|Team Honda Racing]] [[satellite team]]. This engine was extensively modified by [[Mugen Motorsports|Mugen]] and was the first turbocharged Honda engine used in the series: prior GT-spec NSXs used a variant of the [[naturally aspirated]] [[#C32B|C32B]] engine. Though the exact performance figures were kept secret, it is rumored to output more than {{convert|500|bhp|0|abbr=on}}.

Applications:
* 1991-1996 [[Honda NSX]] (5-Speed [[Manual Transmission]])
* 1991-2005 [[Honda NSX]] (4-Speed [[Automatic Transmission]])
* 1994-1996 [[Honda NSX (first generation)#24 Hours of Le Mans|Honda NSX]] [[24 Hours of Le Mans|Le Mans]]
* 2004 [[Honda NSX (first generation)#JGTC and Super GT|Honda NSX-GT]] [[Super GT]]

==C32A==

The '''C32A''' is a {{convert|3206|cc|L|1|abbr=on}} version. The [[SOHC]] depending on model year, produces {{convert|200|hp|PS kW|0|abbr=on}} or {{convert|230|hp|kW|0|abbr=on}}.

Applications;
* C32A - SOHC USDM - {{convert|200|hp|PS kW|0|abbr=on}} and {{convert|29|kgm|0|abbr=on|order=flip}}
** 1991-1995 [[Acura Legend]] [[sedan (car)|sedan]]
** 1991-1992 [[Acura Legend]] [[coupé]]
* C32A1 - Also known as the "Type-II"; uses a higher flowing intake manifold and slightly more aggressive camshaft - SOHC USDM - {{convert|230|hp|PS kW|0|abbr=on}} at 6200 rpm and {{convert|28.5|kgm|0|abbr=on|order=flip}} at 5000 rpm.
** 1994-1995 [[Acura Legend]] GS sedan
** 1993-1995 [[Acura Legend]] LS and L coupe
* C32A5 - SOHC JDM - {{convert|200|hp|PS kW|0|abbr=on}} and {{convert|29|kgm|0|abbr=on|order=flip}}
** 1995-1998 [[Honda Inspire]]/Honda Saber
* C32A6 - SOHC USDM - {{convert|200|hp|PS kW|0|abbr=on}} and {{convert|29|kgm|0|abbr=on|order=flip}}
** 1996-1998 [[Acura TL|Acura 3.2TL]]

==C32B==
The '''C32B''' is a highly tuned [[DOHC]] V6 used in the [[Honda NSX]], which produces {{convert|290|bhp|PS kW|0|abbr=on}} at 7,100 rpm and {{convert|31|kgm|0|abbr=on|order=flip}} at 5,500 rpm of [[Torque#Machine torque|torque]], retaining the 10.2:1 compression ratio from the C30A. The engine is essentially an update to the C30A and does not share commonality with the C32A. Honda increased [[Engine displacement|displacement]] to {{convert|3179|cc|L cuin|1|abbr=on}} through the use of larger {{convert|93|mm|in|2|abbr=on}} [[piston]]s over the {{convert|90|mm|in|2|abbr=on}} used in the C30A, while leaving the {{convert|78|mm|in|2|abbr=on}} stroke the same. To accommodate the larger pistons, Honda used an advanced metallurgical technique on the cylinders called Fiber Reinforced Metal (FRM), in which an ultra lightweight alumina-carbon fiber is cast into the traditional aluminum alloy for enhanced rigidity. This process allowed thinner cylinder walls to be used while providing acceptable cooling characteristics. The C32B also used {{convert|36|mm|in|1|abbr=on}} intake valves, which are {{convert|1|mm|in|2|abbr=on}} larger than those in the C30A.

Applications:
* 1997-2005 [[Honda NSX (first generation)|Honda NSX]] (6-Speed [[manual transmission]])
* 1996-2002, 2005-2009 [[Honda NSX (first generation)#JGTC and Super GT|Honda NSX-GT]] [[Super GT]]
* 2002 [[Vemac RD320R]] [[Super GT]]

==C35A==

The '''C35A''' is a [[SOHC]] and carries the largest displacement of the C series at {{convert|3473|cc|L cuin|1|abbr=on}}. The C35A was the first mass-produced engine to use block forged connecting rods contributing to precise balancing and an exceptionally strong bottom end.<ref name="G2: DIY: Engine Swaps: C35 Swap">{{cite web |url=http://www.acuralegendwiki.org/index.php?title=G2:_DIY:_Engine_Swaps:_C35_Swap |title=G2: DIY: Engine Swaps: C35 Swap |publisher=Acuralegendwiki.org |date=2010-01-02 |access-date=2012-01-27 |archive-date=2012-04-25 |archive-url=https://web.archive.org/web/20120425022709/http://www.acuralegendwiki.org/index.php?title=G2:_DIY:_Engine_Swaps:_C35_Swap |url-status=dead }}</ref> The C35 also contains a balance shaft to dampen engine vibrations associated with 90 degree design V6 engines.<ref name="G2: DIY: Engine Swaps: C35 Swap" /> Besides the addition of these forged components, the overall design is similar to its smaller counterpart the C32A, with some parts being interchangeable. The 9.6:1 compression ratio of the C32A is also retained, despite the increase in displacement.<ref name="G2: DIY: Engine Swaps: C35 Swap" />

Applications:
* C35A - SOHC JDM - {{convert|212|bhp|PS kW|0|abbr=on}}
** 1996-2004 [[Honda Legend]] 
* C35A1 - SOHC USDM - {{convert|210|-|225|bhp|PS kW|0|abbr=on}}
** 1996-2001 [[Acura 3.5RL]]; {{convert|210|bhp|PS kW|0|abbr=on}} at 5200 rpm and {{convert|31|kgm|0|abbr=on|order=flip}} of torque at 2800 rpm<ref name="1996 Acura 3.5 RL- Specifications">{{cite web|url=http://www.hondanews.com/channels/282/releases/48640ee6-1c44-96d4-420c-21004c34c9dc |archive-url=https://web.archive.org/web/20120331070525/http://www.hondanews.com/channels/282/releases/48640ee6-1c44-96d4-420c-21004c34c9dc |url-status=dead |archive-date=2012-03-31 |title=1996 Acura 3.5 RL- Specifications |publisher=Hondanews.com |access-date=2012-01-27 }}</ref>
** 2002-2004 [[Acura 3.5RL]]; {{convert|225|bhp|PS kW|0|abbr=on}} at 5200 rpm and {{convert|32|kgm|0|abbr=on|order=flip}} of torque at 2800 rpm
* C35A2 - SOHC EDM - {{convert|202|bhp|PS kW|0|abbr=on}}
** 1996-1998 [[Honda Legend]]  
* C35A5 - SOHC EDM - {{convert|205|bhp|PS kW|0|abbr=on}}
** 1998-2004 [[Honda Legend]]

==C35B==

The '''C35B''' (name unconfirmed) is a [[DOHC]] V6 with [[VTEC]] which shares basic design properties with its [[SOHC]] non-[[VTEC]] counterpart but with more aggressive camshafts and slightly lighter cylinder walls. This was the only [[DOHC]] [[VTEC]] V6 ever built by [[Honda]] for longitudinal applications and was only used in one non-production car, the Honda FS-X concept.

Applications:
* 1991 Honda FS-X concept - {{convert|280|hp|PS kW|0|abbr=on}}

==See also==

* [[List of Honda engines]]

==References==
<references />

{{Honda}}{{Honda automotive engine timeline (1971-1999)}}{{Honda automotive engine timeline (2000-present)}}

[[Category:Honda engines|C]]
[[Category:Rover engines]]
[[Category:V6 engines]]
[[Category:Engines by model]]
[[Category:Gasoline engines by model]]