View source for Mazda K engine

{{short description|Japanese V6 car engine design}}
{{One source|date=November 2018}}
{{Infobox automobile engine
|name=Mazda K engine
|manufacturer=[[Mazda]]
|production=1991–2002
|successor=[[Mazda AJ engine]]
|configuration=60° [[V6 engine|V6]]
|valvetrain=[[Overhead camshaft#Dual overhead camshaft|DOHC]] [[Multi-valve#Four valves|4 valves]] x cyl.
|image=Mazda Klze.jpg
|block=Aluminium
|head=Aluminium
|redline=7,000
|fueltype=[[Petrol engine|Gasoline]]
|fuelsystem=[[Fuel injection]]
|coolingsystem=[[Radiator (engine cooling)|Water cooled]]
|displacement={{convert|1845|cc|L|1|order=flip|abbr=on}}<br/>{{convert|1995|cc|L|1|order=flip|abbr=on}}<br/>{{convert|2255|cc|L|1|order=flip|abbr=on}}<br/>{{convert|2497|cc|L|1|order=flip|abbr=on}}
|bore={{convert|75|mm|in|2|abbr=on}}<br/>{{convert|78|mm|in|2|abbr=on}}<br/>{{convert|80.3|mm|in|2|abbr=on}}<br/>{{convert|84.5|mm|in|2|abbr=on}}
|stroke={{convert|69.6|mm|in|2|abbr=on}}<br/>{{convert|74.2|mm|in|2|abbr=on}}
|supercharger=[[Twin-screw type supercharger|Twin-screw type]] (on KJ-ZEM)
|power={{convert|130-217|hp|kW PS|0|abbr=on}}
|torque={{convert|115-210|lbft|Nm|0|abbr=on}}
}}
The [[Mazda]] '''K-series''' [[automobile]] engine is a short stroke 60° 24-valve [[V6 engine|V6]] with belt-driven [[Overhead camshaft#Dual overhead camshaft|DOHC]] and all-aluminium construction. Displacements range from 1.8&nbsp;L to 2.5&nbsp;L. They all use a 27-degree DOHC valvetrain with directly actuated hydraulic bucket [[Valve lifter|lifter]]s. The K-series also features a highly rigid aluminum split-crankcase engine block design with 4-bolt mains with additional bolts securing the lower block, an internally balanced [[forged steel]] [[crankshaft]] with lightweight powder forged carbon steel [[connecting rod]]s. They were designed with the intent of being as compact as possible for short-hood [[front-wheel drive]] applications.

One unique innovation of the K-series was the introduction of [[Variable Resonance Induction System]] ('''VRIS'''). Based on the [[Helmholtz resonance]] principle, the intake manifold is equipped with 3 chambers tuned to a specific resonant frequency. The computer dynamically switches between each resonant chamber to achieve the appropriate resonant frequency for the engine's rpm. This effect optimizes volumetric efficiency over a given rpm range to provide maximum torque over the entire rpm range. VRIS is used on the K8, KF, and KL but nearly all modern Mazda V6s are now using this technology.

The K-series all have a 7,000&nbsp;rpm redline with 7500-7800&nbsp;rpm limiter, which given the engine design is conservative. The KJ-ZEM [[Miller cycle]] engine had a 6,000&nbsp;rpm redline, but was only available with an [[automatic transmission]].

==K8==

The {{convert|1845|cc|L|1|order=flip|abbr=on}} '''K8''' is among the [[list of automotive superlatives|smallest production]] V6 engines ever; and also the first K-series engine to be used in a Mazda car (in the [[Mazda MX-3]]). It was a [[DOHC]] 4-valve design with [[VRIS]] and a bore and stroke of {{convert|75x69.6|mm|in|2|abbr=on}}. It produced {{convert|130|hp|kW PS|0|abbr=on}} in US trim (sometimes referred to as '''"K8-DE"'''), and {{convert|135|hp|kW PS|0|abbr=on}} in Japanese trim (the '''"K8-ZE"''') on introduction in 1991 and {{convert|144|hp|kW PS|0|abbr=on}} and {{convert|115|lbft|Nm|0|abbr=on}} at its best. The displacement was held under 2000cc to minimize the annual Japanese [[Road tax#Japan|road tax]] obligation.

Applications:
* [[Mazda MX-3]]
* [[Eunos 500]]

==KF==

* 2.0&nbsp;L '''KF''' - {{convert|1995|cc|L|1|order=flip|abbr=on}} {{convert|78x69.6|mm|in|2|abbr=on}} bore and stroke - The 2.0&nbsp;L '''KF''' engine was available in various states of tune. The '''KF-DE''' produced {{convert|140|hp|kW PS|0|abbr=on}} and {{convert|132|lbft|Nm|0|abbr=on}} and later on {{convert|144|hp|kW PS|0|abbr=on}} and {{convert|132|lbft|Nm|0|abbr=on}}. The [[Japanese domestic market|JDM]] version '''KF-ZE''' engine produced {{convert|160|hp|kW PS|0|abbr=on}} and {{convert|132|lbft|Nm|0|abbr=on}}. The Lantis Type R variant produced {{convert|170|hp|kW PS|0|abbr=on}} and {{convert|140|lbft|Nm|0|abbr=on}}.

{{hidden begin
|title      = Applications:
|titlestyle = background:#88FF88; text-align:left;
|bodystyle  = text-align:left;
}}
* 1991-1997 [[Mazda MX-6]]
* 1992-1993 [[Eunos 500]], {{convert|160|hp|kW PS|0|abbr=on}} {{convert|180|Nm|lbft|0|abbr=on}}
* 1993-2002 [[Eunos 800]]
* 1992-1998 [[Efini MS-8]]
* 1993-1999 [[Xedos 6]]
* 1993-2002 [[Xedos 9]]
* 1993-1996 [[Mazda Lantis]] Type R  170 hp (124 kW; 172 PS) 190 N•m (140 lb•ft)
* 1994-1996 [[Mazda Lantis|Mazda 323f]] V6 GLX
* 1996-1998 [[Mazda Lantis|Mazda 323f]] ZXi
* 1992-1995 [[Ford Telstar]] TX5 Ghia
* 1993-2003 [[Mazda 626]] LX
{{hidden end}}

==KJ-ZEM==<!-- This section is linked from [[Miller cycle]] -->

The {{convert|2255|cc|L|1|order=flip|abbr=on}} {{convert|80.3x74.2|mm|in|2|abbr=on}} bore and stroke,  '''KJ-ZEM''' was one of Mazda's most technologically advanced engines. It employs the "[[Miller cycle]]" which uses a [[supercharger]] to increase compression efficiency by decreasing the compression losses (i.e., flywheel energy used to compress the intake charge in the cylinder); and thereby increasing the net power output of the V6. It was used in the T-platform cars. The supercharger used is the [[Twin-screw type supercharger|twin-screw type]] with electronic boost control. Power output was {{convert|217|hp|kW PS|0|abbr=on}} and {{convert|210|lbft|Nm|0|abbr=on}}. The KJ-ZEM was on the [[Ward's 10 Best Engines]] list for 1995 through 1998.

Applications:
* [[Mazda Millenia]] S
* [[Eunos 800]]
* [[Mazda Xedos 9]]

==KL==

The {{convert|2497|cc|L|1|order=flip|abbr=on}} '''KL''' family uses an {{convert|84.5x74.2|mm|in|2|abbr=on}} bore and stroke. It includes the Japan-only '''KL-ZE''', which produced {{convert|200|hp|kW PS|0|abbr=on}} and {{convert|165|lbft|Nm|0|abbr=on}}. Another variant, the '''KL-DE''' (also known as the '''KL-03''' outside the US, and fitted to 2.5-litre [[Ford Probe]]s) was the worldwide version, with {{convert|164-174|bhp|kW PS|0|abbr=on}} in various applications. In 1998 a revised version of the KL known as the KL-G4 was used in the 626. It featured solid lifters, a cast crankshaft to reduce rotating mass and a reworked intake system. The distributor was replaced with a Ford EDIS coil-pack ignition.

Mazda introduced a key technology with these engines, known as the [[Variable length intake manifold|Variable Resonance Induction System (VRIS)]]. A series of two butterfly valves coupled with electronically controlled actuators varied the volume and length of a resonant chamber within the intake manifold. The valves actuate at particular induction frequencies to produce optimal torque/horsepower output at any given engine speed. The valve operates to create three specific first-order resonant frequencies that increase cylinder air charge. All three resonances are used from 0 to 6250&nbsp;rpm (6800 for the KL-ZE). Above that threshold, the first primary resonant chamber is again used, but at this engine speed the pressure wave from the second-order resonant frequency aids in charging the cylinder.

{{hidden begin
|title      = Applications:
|titlestyle = background:#88FF88; text-align:left;
|bodystyle  = text-align:left;
}}
* KL-DE
** 1993-1997 [[Mazda MX-6]] LS (A spec)
** 1993-1997 [[Ford Probe]] GT

** 1993-1997 [[Mazda 626]] ES, LX (after 1994)
** 1995-2002 [[Mazda Millenia]] L
* KL-ZE
** 1992-1995 [[Ford Telstar]] TX5 Ghia, TX5 Ghia 4ws
** 1997 [[Mazda Capella]] ''Wagon''
** 1993+ Mazda 626 Jspec ''Sedan''
** 1993+ Mazda MX-6 Jspec
** 1993+ Mazda MS-8 (Japan)
** 1993+ Mazda Eunos 600/800 (Japan)
* KL-G4
** 1998-2002 [[Mazda 626]] ES, LX
{{hidden end}}

==References==
{{commons category|Mazda K engines}}
* {{Cite journal |last1=Sakono |first1=Takashi |last2=Takizawa |first2=Shinobu |last3=Harada |first3=Setsuo |last4=Ikeda |first4=Tatsuji |last5=Abe |first5=Hiroshi |date=1992-02-01 |title=Mazda New Lightweight and Compact V6 Engines |url=http://www.tsentraal.ee/mx6/engine/SAE920677.htm |doi=10.4271/920677 |journal=SAE Technical Paper |series=SAE Technical Paper Series |volume=1 |article-number=920677 }}

{{Mazda vehicles}}


{{DEFAULTSORT:Mazda K Engine}}
[[Category:Mazda engines|K]]
[[Category:V6 engines]]
[[Category:Gasoline engines by model]]