Editing Toyota R engine

{{Use dmy dates|date=April 2020}}
{{Infobox automobile engine
| name = Toyota R engine
| image = 18R-G engine in 1974 Toyota Corona, TORC 2014.jpg
| production = 1953–1997
| manufacturer = [[Toyota]]
| configuration = [[Inline-four engine|Inline-four]]
| block = [[Cast Iron]]
| head = [[Cast Iron]]<br>[[Aluminium]]
| valvetrain = [[Overhead valve engine|OHV]] 2 valves per cyl<br>[[SOHC]] 2 valves per cyl<br>[[DOHC]] 2 valves per cyl
| timing = [[Timing Chain]]
| compression = 7.5:1-10.0:1
| turbocharger = Hitachi CT20 on 22R-TE only
| fuelsystem = [[Carburetor]]<br>[[Multi-port fuel injection]]
| fueltype = [[Petrol engine|Gasoline]]
| oilsystem = [[Wet sump]]
| coolingsystem = [[Radiator (engine cooling)|Water-cooled]]
| power = {{convert|45|-|101|kW|PS hp|0|abbr=on}}
| torque = {{convert|108|-|234|Nm|lbft|0|abbr=on}}
| caption = Modified 18R-G engine in a 1974 [[Toyota Corona (T100)|Toyota Corona]] Hardtop
}}

The '''[[Toyota]] R family''' was a series of [[Inline-four engine|inline-four]] [[gasoline]] automobile engines. Designed for [[Longitudinal engine|longitudinal]] placement in such vehicles as the [[Toyota Celica|Celica]] and [[Toyota Hilux|Hilux]] and in production from 1953 through 1997, usage faded out as many of Toyota's mainstream models moved to front-wheel drive. [[Overhead camshaft engine|Overhead cam (OHC)]] versions featured a chain-driven [[camshaft]].

==History of the R family==

===R===
[[File:1953 Toyota R Type engine.jpg|thumb|1953 Toyota R engine.]]

The {{convert|1453|cc|L|1|abbr=on|order=flip}} '''R''' family was produced from 1953 through 1964, and was originally manufactured at the [[Toyota Honsha plant]].

Bore and stroke was {{convert|77x78|mm|in|2|abbr=on}}.<ref name="RT20parts">Corona 1500 Parts Catalog, No.53282-67</ref> In common with new engines of the time, it was made from cast iron (both the block and the head), water cooled, used a three [[Bearing (mechanical)|bearing]] crank, 12V electrics and a side-mounted gear-driven [[camshaft]] controlling [[overhead valve]]s via pushrods in a [[Reverse-flow cylinder head|non-cross flow]] head (exhaust and [[inlet manifold]]s being on the same side of the engine).<ref name="RT20parts"/> Induction was by a twin throat down-draft [[carburettor]], the [[compression ratio]] was 8.0:1 and the total weight was {{convert|155|kg|abbr=on}}.<ref name="RT20parts"/> An [[Autogas|LPG]] version, the '''R-LPG''', was produced for the last two years.

The R engine was the Toyota engine used in the 1958 [[Toyota Crown]], the first model to be exported to the United States. ''[[Road & Track]]'' was unimpressed with the engine on its introduction, noting that it idled quietly but was "not capable of very high revolutions per minute."

{| class="wikitable"
|-
! Code
! Power
! Torque
! Years
! Comments
|-
| R
| {{convert|45|kW|PS hp|0|abbr=on}} at 4,400 rpm
| {{convert|108|Nm|lbft|0|abbr=on}} at 2,600 rpm
| 1953–1964
|
|-
| R-LPG
| 
| 
| 1962–1964
| LPG
|}

Applications:
* 1953–1955 [[Toyota Super]]
* 1955–1956 [[Toyota Master]]
* 1955–1958 [[Toyota Crown]]

===2R===
The {{convert|1490|cc|L|1|abbr=on|order=flip}} '''2R''' family was produced from 1964 through 1971. It is a [[Stroke ratio#Square engine|square engine]], with bore and stroke of {{convert|78|mm|2|abbr=on}}.

Again, an [[Autogas|LPG]] version, the '''2R-LPG''', was produced alongside the gasoline version. Production had been gradually transferred from the original Honsha plant to the new [[Toyota Kamigo plant]] in 1968.

{| class="wikitable"
|-
! Code
! Power
! Torque
! Years
! Comments
|-
| 2R
| {{convert|55|kW|PS hp|0|abbr=on}} at 5,000&nbsp;rpm
| {{convert|116|Nm|lbft|0|abbr=on}} at 2,600&nbsp;rpm
| 1964–1969
|
|-
| 2R-LPG
| 
| 
| 1964–1969
| LPG
|}

Applications:<ref name="Riken71">{{citation | title = Piston Ring Sets Price List | url = http://grot66.ru/RIKEN+PISTON+RING+SIZE+LIST+18.pdf | archive-url = https://web.archive.org/web/20130531201214/http://grot66.ru/RIKEN+PISTON+RING+SIZE+LIST+18.pdf | url-status = dead | archive-date = 2013-05-31 | page = 71 | volume = 18 | publisher = Riken Corporation | date = November 2008 | location = Tokyo, Japan }}</ref>
* 1964 – January 1970 [[Toyota Corona]] RT40/RT46V/RT50/RT56
* February 1970 – January 1971 [[Toyota Corona]] RT80/90/86V
* 1968–1971 [[Toyota Mark II]]
* Toyota Bus RH15B
* 1965–1967 [[Toyota Stout]] RK43/RK47
* [[Toyota ToyoAce]] PK41
* [[Toyota Hilux]] RN10

===3R===
[[File:Toyota 3R-C Engine.jpg|thumb|Toyota 3R-C engine]]

The {{convert|1897|cc|L|1|abbr=on|order=flip}} '''3R''' family was produced from 1959 through 1968.

When introduced it had a 7.7:1 compression ratio. In 1960 the 3R was uprated to 8:1 and the '''3R-B''' version was offered from 1960 through 1968 with the old 7.7:1 compression ratio. The '''3R-C''' was introduced to comply with California emissions laws. The '''3R-LPG''' variant was produced for the last five years.

{| class="wikitable"
|-
! Code
! Power
! Torque
! Years
! Comments
|-
| 3R
| {{convert|59|kW|PS hp|0|abbr=on}} at 4,600 rpm
| {{convert|142|Nm|lbft|0|abbr=on}} at 2,600 rpm
| 1959–1960
| 7.7 CR
|-
| 3R
| {{convert|66|kW|PS hp|0|abbr=on}} at 5,000 rpm
| {{convert|142|Nm|lbft|0|abbr=on}} at 3,400 rpm
| 1960–1968
| 8.0 CR
|-
| 3R-B
| {{convert|59|kW|PS hp|0|abbr=on}} at 4,600 rpm
| {{convert|142|Nm|lbft|0|abbr=on}} at 2,600 rpm
| 1960–1968
| 7.7 CR
|-
| 3R-C
| 
| 
| 
| emissions control – California
|-
| 3R-LPG
| 
| 
| 1963–1968
| LPG
|}

Applications:
* 1963–1968 [[Toyota Dyna]]
* 1964–1967 [[Toyota Stout]], originally {{convert|85|PS|kW hp|0|abbr=on}}
* 1969–? [[Toyota Hilux]]
* 1967–1969 [[Toyota Corona]] (US)
* 1959–1967 [[Toyota Crown]]
* 1960–1967 [[Toyopet Masterline]]

===4R===
The {{convert|1587|cc|L|1|abbr=on|order=flip}} '''4R''' family was produced from 1965 through 1968.

Bore and stroke was {{convert|80.5x78|mm|abbr=on}}.

Applications:
* 1967 [[Toyota Corona (T50)|Toyota 1600S]] (Japan)

===5R===
The {{convert|1994|cc|L|1|abbr=on|order=flip}} '''5R''' family was produced from 1968 through 1986. An [[Autogas|LPG]] version, the '''5R-LPG''', was produced from 1968 through 1983.

It is a 2-valve [[OHV engine]]. [[Cylinder bore]] and stroke are {{convert|88x82|mm|in|2|abbr=on}}. Output was {{convert|106|hp|kW hp PS|0|abbr=on|order=out}} at 5200&nbsp;rpm and {{convert|125|lbft|Nm|0|abbr=on|order=flip}} at 3000&nbsp;rpm. Trucks such as the Dyna received a version tuned for torque, with a maximum power of {{convert|80|PS|kW hp PS|0|abbr=on|order=out}} at 4600&nbsp;rpm and torque of {{convert|145|Nm|lbft|0|abbr=on}} at 3000&nbsp;rpm.<ref name="inufa82">{{citation |ref=INK82 |title=Internationaler Nutzfahrzeug-Katalog (Inufa) 1982 |trans-title=International Commercial Vehicle Catalog |language=German |volume=24 |location=Solothurn, Switzerland |publisher=Vogt-Schild AG |year=1982 |pages=114–115 |editor-first=Hans U. |editor-last=Rohrbach}}</ref>

Applications:
*[[Toyota Crown]]: third through sixth generation (RS50, RS60/66, RS80/RS100, and RS110). Only with LPG for taxi use in the last two generations.
*1969-1977 [[Toyota Coaster]] RU18/RU19
*[[Toyota Dyna]] RU10/RU20/RU30
*[[Toyota Stout]] RK101
*[[Toyota ToyoAce]] RY20
*Aug 1981–? [[Toyota Corona]] sixth generation (RT131), only LPG combined with [[automatic transmission]].

===6R===
The {{convert|1707|cc|L|1|abbr=on|order=flip}} '''6R''' was produced from 1969 through 1974. Output is {{convert|107|hp|kW PS|0|abbr=on}} at 5,300&nbsp;rpm. The '''6R-B''' was produced those same years, while the natural gas powered '''6R-LPG''' was produced from 1970 through 1973.

;Applications:
* Sep 1970 – Jul 1973 [[Toyota Corona (T80)|Toyota Corona]] RT84/94
* Jan 1972 – Aug 1973 [[Toyota Mark II (X10)|Toyota Mark II]] RX16V – {{convert|95|PS|kW|abbr=on}}<ref name=toycomm>{{citation | ref = love | script-title=ja:愛される車づくり。トヨタはあすにいどみます。|trans-title=Lovable car manufacture. Toyota dares to defy tomorrow. | language = Japanese | year = 1972 | type = catalog | publisher = Toyota Motor Co. | page = 1 }}</ref>

===7R===
The {{convert|1591|cc|L|1|abbr=on|order=flip}} '''7R''' was produced from 1968 through 1971 with a twin throat down-draft carburettor.<ref name="RT41parts">Toyota Corona Deluxe, Parts Catalog, No.53212-68</ref><br />
The '''7R-B''' was produced from 1968 through 1969 with dual [[SU carburetor]]s and higher compression.<br />
The '''7R-LPG''' was produced from 1969 through 1970.

The 7R was similar in displacement and technology to the 4R except the wider {{convert|86|mm|2|abbr=on}} bore and shorter {{convert|68.5|mm|2|abbr=on}} stroke of the 7R gave different power characteristics.

{| class="wikitable"
|-
! Code
! Power
! Torque
! Compression
! Years
! Comments
|-
| 7R<ref name="RT41parts"/>
| {{convert|63|kW|PS hp|0|abbr=on}} at 5,500 rpm
| {{convert|123|Nm|lbft|0|abbr=on}} at 3,800 rpm
| 8.5
| 1968–1971
|
|-
| 7R-B<ref name="RT41parts"/>
| {{convert|75|kW|PS hp|0|abbr=on}} at 6,200 rpm
| {{convert|133|Nm|lbft|0|abbr=on}} at 4,200 rpm
| 9.5
| 1968–1969
| Dual SU carburettors
|-
| 7R-LPG
|
|
|
| 1969–1971
| LPG
|}

Applications:
* 1968–1970 [[Toyota Corona]] (RT41 sedan, RT53 hardtop, RT54 hardtop)
* 1970 [[Toyota Corona]] (RT82 sedan)
* 1968–1970 [[Toyota Mark II (T70)|Toyota Corona Mark II]] (RT6x)
* 1968–1971 [[Toyota Mark II (T70)|Toyota Corona Mark II Wagon]] (RT76D)<ref>{{citation | title = Wagon: Corona Mark II Wagon | language = Japanese | publisher = Toyota | type = sales sheet }}</ref>

{{anchor|8R-G}}

===8R===
[[File:8R engine in a 1971 Toyota Hilux.jpg|thumb|Toyota 8R engine in a Hilux]]

The {{convert|1858|cc|L|1|abbr=on|order=flip}} '''8R''' The engine was produced from 1968 through 1973.<br />
Cylinder bore and stroke was {{convert|85.9x80|mm|in|abbr=on}} with a five bearing crank.<br />
It was also available as the '''8R-D''', dual SU '''8R-B''', [[Electronic fuel injection|EFI]] '''8R-E''', Californian-spec '''8R-C''' and [[DOHC]] '''8R-G'''.

It was a major departure for the R family.  With a 2-valve [[SOHC]] head, it impressed contemporary reviewers – ''[[Road & Track]]'' praised its quietness and free-revving nature.

The 8R engine has a closed chamber head vs the open chamber of the 18R-C.{{cn|date=December 2020}} The 8R-B has dual side draft [[SU carburettor|SU-type]] Aisan carburettors with the float bowl under the body and vacuum activated power valves with strangle plates for chokes and liquid cooled intake with a balance tube.{{cn|date=December 2020}}

Toyota upped the ante again with the [[DOHC]] (but still 2-valve) '''8R-G''', produced from 1969 through 1972. From 1969 to Feb 1971 it was known as the '''10R''', but along with a removal of the tensioner gear in the interest of quieter operation, it was renamed the 8R-G to reflect the decision that twin-cam engines were henceforth to be identified by a "-G" suffix.<ref name="TC27">{{citation | title = All About the Toyota Twin Cam, 2nd ed. | url = http://www.3sgte.com/page_29.htm | page = 27 | publisher = Toyota Motor Company | year = 1984 | location = Tokyo, Japan }}</ref> 4,931 twin cam engines were built, all installed in the [[Toyota Corona Mark II]] (RT72) 1900 GSS. The 10R/8R-G weighed in at {{convert|170|kg|abbr=on}} and as such was both lighter and more compact than its less powerful predecessor the '''[[#9R|9R]]'''<ref name="twincams">[http://www.3sgte.com/page_8.htm ''Toyota Twin Cam''], p. 6</ref>

{| class="wikitable"
|-
! Code
! Power
! Torque
! Compression
! Years
! Comments
|-
| 8R
| {{convert|81|kW|hp PS|0|abbr=on}} at 5,500 rpm
| {{convert|153|Nm|lbft|0|abbr=on}} at 3,800 rpm
| 9.0
| 1968–1972
|
|-
| 8R-B
| {{convert|82|kW|hp PS|0|abbr=on}} at 6,000 rpm
| {{convert|152|Nm|lbft|0|abbr=on}} at 4,000 rpm
| 10.0
| 1969–1971
| Dual [[SU carburetor]]s
|-
| 8R-D
|
|
|
| 
|
|-
| 8R-E
|
|
|
| 
| EFI
|-
| 8R-C
| {{convert|81|kW|hp PS|0|abbr=on}} at 5,500 rpm
| {{convert|174|Nm|lbft|0|abbr=on}} at 3,600 rpm
| 9.0
| 
| Californian emissions controls
|-
| 8R-G
| {{convert|104|kW|hp PS|0|abbr=on}} at 6,400 rpm
| {{convert|166|Nm|lbft|0|abbr=on}} at 5,200 rpm
|
| 1969–1972
| DOHC, dual side-draft carburettors
|}

Applications:
* 1970–1971 [[Toyota Hilux]], {{convert|72|kW|hp PS|0|abbr=on}}
* 1971–1973 [[Toyota Corona]] 1900 hardtop
* [[Toyota Corona Mark II]] RT72 Corona Mark II 1900 hardtop
* [[Toyota Corona Mark II]] RT72 Corona Mark II 1900 hardtop GSS (8R-G)

===9R===
[[File:Toyota 9R engine 02.jpg|thumb|Toyota 9R engine in a Corona]]

The {{convert|1587|cc|L|1|abbr=on|order=flip}} '''9R''' was produced from 1967 through 1968. Bore and stroke {{convert|80.5x78|mm|abbr=on}}.

It was essentially a 4R with a [[DOHC]] head designed by [[Yamaha Motor Company|Yamaha]]. The cam lobes activated the valves directly via a bucket over shim arrangement. This same arrangement was used on the 2M, 8R-G, 10R, 18R-G, 2T-G, 4A-GE and 3T-GTE engines (all designed by Yamaha).

Output was {{convert|82|kW|hp PS|0|abbr=on}} at 6,200&nbsp;rpm and {{convert|136|Nm|lbft|0|abbr=on}} at 5,000&nbsp;rpm. It was a 2-valve [[DOHC]] design with two [[Solex Carburetor|Solex]] carburettors and weighed {{convert|174|kg|abbr=on}}. A total of 2,229 9R engines were built.<ref name="twincams"/>

Applications:
* [[Toyota Corona (RT55)]] 1600 GT hardtop

===10R===
The twin cam {{convert|1858|cc|L|1|abbr=on|order=flip}} '''10R''' was produced from 1967 through Feb 1971, when it was renamed the [[#8R-G|8R-G]]. The later 8R-G version did not receive a timing chain tensioner in an effort to make it more silent.<ref name="TC27"/>

Output was {{convert|104|kW|hp PS|0|abbr=on}} at 6,400&nbsp;rpm and {{convert|166|Nm|lbft|0|abbr=on}} at 5,200&nbsp;rpm.

Applications:
* [[Toyota Corona Mark II]] RT75 Corona Mark II GSS

===12R===
The {{convert|1587|cc|L|1|abbr=on|order=flip}} '''12R''' was produced from 1969 through 1988. It was also built in the Philippines as the '''12R-M''',<ref name="VIM">{{Citation | title = Toyota Vehicle Identification Manual | publisher = Toyota Motor Sale Co., Ltd. – Export Parts Department | year = 1984 | id = 97913-84 }}</ref> by Toyota's local affiliate [[Delta Motors Corporation]].<br />
Technical Specs (Finnish Owner's Manual from 1973 Corona Mark 1)<br />
– Four cylinder, 4-stroke, OHV <br />
– Bore × stroke: {{convert|80.5x78|mm|abbr=on}} <br />
– Compression ratio: 8.5:1 <br />
– Maximum power: {{convert|90|PS|kW hp|0|abbr=on}} at&nbsp;5400&nbsp;rpm [[SAE International|SAE]]

The '''12R-LPG''', was produced from 1969 through 1983.<br />
Technical Specs: 1975 {{convert|59|kW|PS hp|0|abbr=on}} [[redline]] 4,400&nbsp;rpm

Applications:
* 1971–1978 [[Toyota Corona]]
* 1971–1972 [[Toyota Hilux]]
* 1977 [[Toyota Hiace]]
* 1975 [[Toyota Hiace Commercial Camper]]
* 1976 [[Daihatsu Taft (F20)]]
* [[Delta Mini Cruiser]]/Explorer

=== 16R ===
The OHC {{convert|1808|cc|L|1|abbr=on|order=flip}} '''16R''' was produced from 1974 through 1980. Power output as mounted in a 1980 [[Toyota Mark II|Mark II]] was {{convert|105|PS|kW hp|0|abbr=on}} at 5,600&nbsp;rpm, while a twin carburetted version produced {{convert|110|PS|kW hp|0|abbr=on}} at 6,000&nbsp;rpm.<ref>{{citation | ref = AR80 | title = Automobil Revue '80 | editor1-last = Braunschweig | editor1-first = Robert | editor2-last = Büschi | editor2-first = Hans-Ulrich | publisher = Hallwag, AG | page = 504 | language = de, fr | location = Berne, Switzerland | volume = 75 | date = 6 March 1980 }}</ref> The '''16R-B''' was produced for the first two years. There was also a '''16R-J''' version for various commercial vehicle applications.

Applications:
* October 1975 – February 1977 [[Toyota Carina (A10)|Toyota Carina]] RA10/16
*[[Toyota Mark II|Toyota Mark II Van]] RX37V (16R-J), {{convert|95|PS|kW hp|0|abbr=on}}<ref>{{citation | title = New Mark II Van | language = Japanese | publisher = Toyota Motor Co. | work = Brochure | date = December 1976 | page = 16 | url = https://www.toyota.co.jp/jpn/company/history/75years/vehicle_lineage/catalog/60013056A/page16/x1.jpg | archive-url = https://web.archive.org/web/20240901034700/https://www.toyota.co.jp/jpn/company/history/75years/vehicle_lineage/catalog/60013056A/page16/x1.jpg | archive-date = 2024-09-01 | id = 021112-5112 }}</ref>
*[[Toyota Corona (T100)|Toyota Corona RT102/112/117]] (sedan/hardtop/wagon)
*[[Toyota Corona (T100)|Toyota Corona RT108V]] (van; 16R-J)
*[[Toyota Corona (T130)|Toyota Corona RT137V]] (van; 16R-J)
*[[Toyota HiAce]] RH12/14/17/41 (16R-J)

{{anchor|18R}}
{{anchor|18R-C}}
{{anchor|18R-U}}
{{anchor|18R-E}}

=== 18R ===
[[File:1974 Toyota Celica engine (5948543051).jpg|alt=|thumb|Toyota 18R-C engine in a Celica]]

The '''18R''' series shared a {{convert|1968|cc|L|1|abbr=on|order=flip}} block; cylinder bore and stroke was {{convert|88.5x80|mm|in|abbr=on}}.

The 2-valve, SOHC versions were as follows:
{| class="wikitable"
|-
! Code
! Power
! Torque
! Years
! Comments
|-
| 18R<ref name=retro18R>{{cite book |url=http://www.retrojdm.com/LiteratureViewPage.asp?LiteratureID=2&DPI=150&Filename=29,30%20-%206%20Types%20of%20Engine,%203%20Types%20of%20Transmission.jpg |title=Celica brochure |year=1973 |publisher=Toyota Japan }}{{Dead link|date=July 2018 |bot=InternetArchiveBot |fix-attempted=no }}</ref>
| {{convert|78|kW|PS hp|0|abbr=on}}<br>{{convert|65|kW|PS hp|0|abbr=on}} at 5000&nbsp;rpm
| {{convert|142|-|145|Nm|lbft|0|abbr=on}}<br>{{convert|145|Nm|lbft|0|abbr=on}} at 3600&nbsp;rpm
| 1971–1981 <br> ?
| <br> non-emissions Hilux
|-
| 18R-C
| {{convert|72|kW|PS hp|0|abbr=on}} at 5500&nbsp;rpm
| {{convert|143-145|Nm|lbft|0|abbr=on}} at 3600&nbsp;rpm
| 1971–1981
| emissions control – worldwide (Californian Standards)
|-
| 18R-U
| {{convert|75|kW|PS hp|0|abbr=on}} at 5500&nbsp;rpm
| {{convert|152|Nm|lbft|0|abbr=on}} at 3600&nbsp;rpm
| 1975–1978
| emissions control – Japan
|-
| 18R-E
| {{convert|84-96|kW|PS hp|0|abbr=on}}<ref>{{cite web |url=https://www.toyota-global.com/company/history_of_toyota/75years/vehicle_lineage/car/id60002292/index.html |title=75 Years of TOYOTA {{!}} Carina Hardtop 1st |publisher=Toyota |location=Japan |year=2012 |access-date=2020-01-15}}</ref> at 5600&nbsp;rpm
| {{convert|172|Nm|lbft|0|abbr=on}} at 4400&nbsp;rpm
| 1974–1975
| EFI, Japan only
|}

[[File:Toyota 18R-E engine.jpg|thumb|Japan only 18R-E in a Carina]]Applications:

* 18R/18R-C/18R-U/18R-E
** 1972 [[Toyota Corona]] ''2000''
** 1972 [[Toyota Corona]] ''2000 MK. II''
** 1972 [[Toyota Celica]] ''2000''
** 197X [[Toyota Cressida]] ''2000''/''Gen1''
**[[Toyota Hilux]], 89&nbsp;PS
* 18R-C
** 1972–1974 [[Toyota Hilux]], {{convert|80.5|kW|PS hp|0|abbr=on}}
** 1974–1981 [[Toyota Celica]] ''2000''
** 1980–1981 [[Toyota Corona (T130)|Toyota Corona Liftback]] (RT132, Australia)

{{anchor|18R-G}}
{{anchor|18R-GR}}
{{anchor|18R-GU}}
{{anchor|18R-GE}}
{{anchor|18R-GEU}}

==== 18R-G ====
[[File:18R-GUengine.jpg|thumb|18R-G on an engine stand]]

The 2-valve [[DOHC]] '''18R-G''' and its variations were produced from 1973 to 1982, replacing the [[#8R-G|8R-G]] and providing a performance engine which took advantage of the entire 2-litre limit of Japan's "[[Vehicle size class#Japan|small car]]" class.<ref name="TC27"/> While most 18R-Gs had a head designed and made by [[Yamaha Motor Company|Yamaha]], a very few had Toyota heads.{{Citation needed|date=June 2009}} Yamaha's tuning-fork logo can be seen on the Yamaha heads. Except for the head and related timing components, most parts were shared or interchangeable with the SOHC 18R. Combustion chambers were hemispheric.

[[File:18rg.jpg|thumb|18R-G in an engine bay]]

In 1975, air injection was added to the Japan-market '''18R-GR''' for improved emissions. This used Solex carburettors.<ref name="TC27"/> A [[fuel injected]] and catalyzed Japan-market version, the '''18R-GEU''', was produced from 1978 through 1982. There was also a catalyzed carburetted version, the '''18R-GU'''.

[[File:Bigmikemunizrallycar.jpg|thumb|1973 TE27 Rally Car with a 152E TRD Race Engine]]

Competition versions of the 18R-G and -GE include those used in rally Celicas of the period, one of which finished second in the 1977 [[RAC Rally]]. These had 4-valve heads and were called '''152E''', they were of {{convert|89x80|mm|2|abbr=on}} bore and stroke and {{convert|1995|or|1998|cc|CID|1|abbr=on}} (depending on the source).<ref name=TC1>[http://www.3sgte.com/page_27.htm ''Toyota Twin Cam''], p. 25</ref> The [[Group 4 (racing)|Group 4]] [[rallying|rally]] version of the 152E had two twin-choke carburettors, and developed {{convert|240|PS|kW hp|0|abbr=on}} at 9000&nbsp;rpm.<ref>{{cite web|url=http://i58.photobucket.com/albums/g250/71TA22/Stuff/RA40Rally-1.jpg |title=Toyota RA40 Celica, Modified 18R engine |accessdate=2011-11-08}}</ref> Higher tuned engines developed as much as {{convert|300|PS|kW hp|0|abbr=on}} at 9,200&nbsp;rpm. German racing team [[Schnitzer Motorsport|Schnitzer]] also developed a [[Toyota Celica LB Turbo|turbocharged silhouette racing version]] of the Celica,<ref name="TC1"/> to take on the [[Porsche 935]]. With a [[Kühnle, Kopp & Kausch|KKK]] <!-- a defunct German automotive parts company, not the Ku Klux Klan --> [[turbocharger]], the [[Group 5 (racing)|Group 5]] Celica developed {{convert|560|PS|kW hp|0|abbr=on}} but reliability was less than satisfactory.<ref>{{cite web | title = Bigger Than Life: The Schnitzer Celica | url = http://speedhunters.com/archive/2009/02/19/retrospective-gt-gt-bigger-than-life-the-schnitzer-celica-turbo.aspx | author = Chong, Rod | publisher = Speedhunters.com | date = 2009-02-19 | accessdate = 2011-01-31 | url-status = dead | archiveurl = https://web.archive.org/web/20110119170131/http://speedhunters.com/archive/2009/02/19/retrospective-gt-gt-bigger-than-life-the-schnitzer-celica-turbo.aspx | archivedate = 2011-01-19 }}</ref>

{| class="wikitable"
|-
! Code
! Power
! Torque
! Years
! Weight
! Comments
|-
| 18R-G<ref name="twincams"/><ref name=retro18R/>
| {{convert|145|PS|kW hp|0|abbr=on}} at 6400 rpm
| {{convert|18|kgm|Nm lbft|0|abbr=on}} at 5200 rpm
| 1972–1981
| {{convert|170|kg|lb|0|abbr=on}}
|
|-
| 18R-GR<ref name="twincams"/>
| {{convert|140|PS|kW hp|0|abbr=on}} at 6400 rpm
| {{convert|17.2|kgm|Nm lbft|0|abbr=on}} at 4800 rpm
| 1973–1975
|
| low compression for regular fuel
|-
| 18R-GU<ref name="twincams"/>
| {{convert|130|PS|kW hp|0|abbr=on}} at 5800 rpm
| {{convert|16.5|kgm|Nm lbft|0|abbr=on}} at 4800 rpm
| 1975–1978
| {{convert|182|kg|lb|0|abbr=on}}
| emissions control – Japan.
|-
| 18R-GEU<ref>[http://www.3sgte.com/page_9.htm ''Toyota Twin Cam''], p. 7</ref>
| {{convert|135|PS|kW hp|0|abbr=on}} at 5800 rpm
| {{convert|17.5|kgm|Nm lbft|0|abbr=on}} at 4800 rpm
| 1978–1982
| {{convert|166|kg|lb|0|abbr=on}}
| EFI, emissions control (Japan).
|}

Applications:
* 1973–1981 [[Toyota Celica]] GT 2000
* 1982–1983 [[Toyota Celica]] GT 2000 (RA63)
* 1974–1983 [[Toyota Carina]] GT 2000
* 1978–1983 [[Toyota Camry|Toyota Celica Camry]] GT 2000
* 1973–1982 [[Toyota Corona]] GT 2000

===19R===
The 2-valve [[SOHC]] {{convert|1968|cc|L|1|abbr=on|order=flip}} '''19R''' was produced from 1974 through 1977. Cylinder bore and stroke was {{convert|88.5x80|mm|abbr=on}}. Its dimensions are the same as of the 18R, but it featured [[Toyota TTC|TTC-V]], Toyota's licensed version of Honda's [[CVCC]] [[Stratified charge engine|stratified charge]] combustion system. Output is {{convert|80|PS|kW hp|0|abbr=on}}. The 19R was a short-lived experiment by Toyota, and was only offered in Japanese market cars.

Applications:
* 1974–1977 [[Toyota Carina|Carina RA13/RA31]]<ref>{{cite web | title = Toyota Carina A12 | url = http://www.toyotaoldies.de/gala12.html | first = Alexander | last = Hajek | work = Toyota Oldies | accessdate = 2012-10-03 }}</ref><ref name=Catvol23>{{cite journal | title= Catalogue vol. 23 | ref = JAMA23 | journal = 自動車ガイドブック [Automobile Guide Book] | language = Japanese | volume = 23  | date = 1976-10-20 | publisher = [[Japan Automobile Manufacturers Association]] | location = Japan | page = 99 | id = 0053-760023-3400 }}</ref>
* 1974–1977 [[Toyota Corona (T100)|Corona RT103/RT123]]

===20R===
The 2-valve [[SOHC]] {{convert|2190|cc|L|1|abbr=on|order=flip}} '''20R''' was produced from 1975 through 1980. Cylinder bore and stroke was {{convert|88.5x89|mm|in|abbr=on}}. Aluminum alloy heads were used.

Initial output was {{convert|72|kW|hp PS|0|abbr=on}} at 4800&nbsp;rpm ({{convert|90|hp|kW PS|0|abbr=on}} in [[California]]) and {{convert|162|Nm|lbft|0|abbr=on}} at 2,800&nbsp;rpm. Power was down slightly from 1978 through 1979 at {{convert|71|kW|hp PS|0|abbr=on}} at 4800&nbsp;rpm and {{convert|165|Nm|lbft|0|abbr=on}} at 2400&nbsp;rpm. The final version, from 1979 through 1980, was down again at {{convert|67|kW|hp PS|0|abbr=on}} at 4800&nbsp;rpm (still at {{convert|95|hp|kW PS|0|abbr=on}} in Canada) and {{convert|165|Nm|lbft|0|abbr=on}} at 2400&nbsp;rpm.

The 20R and subsequent models featured important design changes relative to the earlier SOHC R-series engines.  The head was changed from a reverse-flow to a cross-flow type with hemispherical combustion chambers and shorter valve rockers.  The timing chain was strengthened.  The lower block bearings were strengthened against wear, safeguarding oil pressure, and the stroke was lengthened.  The changes increased torque substantially and shifted peak power and torque towards the lower speed range.  The later R series engines did much to establish Toyota's reputation for reliability, which had previously been indifferent at best.

Applications:
* 1975–1980 [[Toyota Hilux]]
* 1975–1980 [[Toyota Celica]] (U.S. Version)
* 1975–1980 [[Toyota Corona]] (U.S. Version)
* [[Toyota Stout (K110)|Toyota Stout]] (RK110/111)
* [[Toyota Coaster]] (RB11)<ref name=Catvol25>{{cite journal | title = Catalogue vol. 25 | ref = JAMA25 | journal = 自動車ガイドブック [Japanese Motor Vehicles Guide Book] | language = Japanese | volume = 25  | date = 1978-10-10 | publisher = [[Japan Automobile Manufacturers Association]] | location = Japan | page = 295 | id = 0053-780025-3400 }}</ref>

{{anchor|21R|21R-C}}
===21R===
The 2-valve [[SOHC]] {{convert|1972|cc|L|1|abbr=on|order=flip}} '''21R''' was produced from 1978 through 1987. Cylinder bore and stroke are {{convert|84x89|mm|in|2|abbr=on}}.

Output for export markets, largely unconstrained by emissions, was {{cvt|100|PS|kW PS hp|0|order=out}} DIN at 5,000&nbsp;rpm and {{convert|154|Nm|lbft|0|abbr=on}} at 4,000&nbsp;rpm. Air injection and federally compliant emissions equipment for the '''21R-C''' (1982–1985) dropped power down to {{cvt|90|hp|kW PS hp|0|order=out}} SAE net at 5,000&nbsp;rpm. The air-injected Japanese version, the '''21R-U''', produces {{cvt|105|PS|kW PS hp|0|order=out}} JIS at 5,200&nbsp;rpm and {{convert|162|Nm|lbft|0|abbr=on}} at 3,600&nbsp;rpm but dropped to {{cvt|100|PS|kW PS hp|0|order=out}} at 5,400&nbsp;rpm and {{convert|154|Nm|lbft|0|abbr=on}} at 4,000&nbsp;rpm in 1986.

Applications:
* 1978–1982 [[Toyota Carina (A40)|Toyota Carina]] RA46-A, RA56-A
* 1978–1981 [[Toyota Celica (A40)|Toyota Celica]] RA46-B
* 1981–1983 [[Toyota Celica (A60)|Toyota Celica]] RA60-B
* 1978–1983 [[Toyota Corona (T130)|Toyota Corona]] RT133
* 1978–1980 [[Toyota Mark II (X40)|Toyota Cressida/Corona Mark II/Chaser]] RX40, RX41
* 1980–1983 [[Toyota Mark II (X60)|Toyota Cressida/Corona Mark II]] RX60<!-- last was Switzerland in August 1983 -->
* 1979–198? [[Toyota HiAce]] Wagon RH23G

===22R===<!-- This section is linked from [[Toyota Celica]] -->
[[File:1989ToyotaHiluxSURF4x4-engine.jpg|thumb|22R-E engine fitted in a 1989 [[Toyota Hilux Surf|Hilux Surf]]]]

The 2-valve [[SOHC]] {{convert|2366|cc|L|1|abbr=on|order=flip}} '''22R''' was produced from 1981 through 1997.

Cylinder bore and stroke was {{convert|92x89|mm|in|2|abbr=on}}.

Initial output was {{convert|72|kW|hp PS|0|abbr=on}} at 4,800&nbsp;rpm and {{convert|174|Nm|lbft|0|abbr=on}} at 2,800&nbsp;rpm. By 1990 the 22R was producing {{convert|81|kW|hp PS|0|abbr=on}} at 5,000&nbsp;rpm and {{convert|187|Nm|lbft|0|abbr=on}} at 3,400&nbsp;rpm.

The first [[fuel injected]] '''22R-E''' engines appeared in August 1982. Output of these engines is commonly rated at {{convert|78|kW|hp PS|0|abbr=on}} at 4,800&nbsp;rpm and {{convert|185|Nm|lbft|0|abbr=on}} at 2,800&nbsp;rpm.

In 1985, the engine was significantly reworked, output was up to {{convert|84|kW|hp PS|0|abbr=on}} at 4,800&nbsp;rpm and {{convert|190|Nm|lbft|0|abbr=on}} at 3,600&nbsp;rpm. Many parts from the newer '''22R/R-E''' are not compatible with those from the older pre-1985 engine. Non-compatible parts include the cylinder head, block, pistons and many of the associated parts such as the timing chain and cover, and water and oil pumps (although the oil pump internals are the same).
These changes also affected the 22R, therefore one can consider the 85–95 22R-E as a fuel injected version of the 85–90 22R with only minor differences, if any.

Toyota swapped the dual-row timing chain used in older engines for a single-row chain with plastic guides in 1983. The new system reduced drag on the engine but introduced a new maintenance problem. After about {{convert|100000|mi|km}} of operation, the chain may stretch to the point that the hydraulic-operated chain tensioner cannot take up any more slack. The timing chain then impacts the plastic driver's side chain guide, breaking it within a short period of time and creating a noticeable chattering sound in the front of the engine, especially when cold. If the engine continues to be operated without the guide restraint, the chain will vibrate excessively on the driver's side and stretch rapidly. The result is any of several failure modes.

First, the loose chain will reduce ignition timing accuracy, which usually results in noticeably rough running. Second, it may jump a tooth on the drive sprocket or break entirely, which almost always results in major damage to an [[interference engine]]. Third, the stretched chain can slap against the side of the timing cover and wear through the metal into the coolant passage behind the water pump, resulting in major damage to both the oil and cooling systems (sometimes mis-diagnosed as a head gasket failure). The damaged aluminum timing cover is difficult to repair effectively and is typically replaced after such an event. Aftermarket timing-chain kits for the 22R/R-E typically include steel-backed guides that do not readily break even after the initial chain stretching has occurred, permitting the chain to run beyond the {{convert|100000|mi|km}} point without further incident. However, some Toyota mechanics will recommend the plastic guides as they will break when the timing chain is stretched; When the guides break a noticeable chatter is heard from the timing chain slapping on the cover, warning the operator of a worn timing chain.

The [[turbocharged]] '''22R-TE''' (sold from late 1985 through 1988) produced {{convert|101|kW|hp PS|abbr=on}} at 4,800&nbsp;rpm and {{convert|234|Nm|lbft|0|abbr=on}} at 2,800&nbsp;rpm.

These engines are extremely well known for their durability, decent fuel efficiency and good low to mid range torque.

However, its weakness is high-end power. The '''22R''' has a large displacement and a strong block, but its comparatively long stroke and restrictive head limit its use in high revving applications. Thus, the Toyota [[Toyota R engine#18R-G|18R-G]], [[Toyota T engine#2T-G|2T-G]], [[Toyota 4A-GE|4A-GE]] and [[Toyota S engine#3S-GE|3S-GE]] 4-cylinder engines are better suited for performance applications.

A popular modification to the early 22R is to use a 20R head. Contrary to popular lore, the 20R head does not have smaller combustion chambers. The misunderstanding originated when the 22R came out and an advantage was its higher compression ratio, so swapping a 20R block with a 22R, there was a compression increase. The 20R head has straight ports, so can flow better than the 22R head, improving high RPM power. The 20R head is a simple bolt-on modification for the pre-1985 block, but also requires the use of the 20R intake manifold, making it almost impossible (there's a lot of matching necessary) to use with the 22R-E EFI system.<ref name="toysport">{{cite web|url=http://www.toysport.com/technical%20information/22r_tech_notes.htm|title=Toysport – 22R Tech Notes|accessdate=2009-10-07|year=2000|url-status=dead|archiveurl=https://web.archive.org/web/20100111044404/http://www.toysport.com/Technical%20Information/22r_tech_notes.htm|archivedate=2010-01-11}}</ref> For blocks 1985 and onwards, further modifications are required.<ref name="lcengineering20r22r">{{cite web|url=http://www.lcengineering.com/LCTechPages/techpages/eng17.html|title=LC Engineering – Using a 20R Head on an 85–95 22RE Block|accessdate=2009-10-07|year=2004}}</ref>

{| class="wikitable"
|-
! Code
! Power
! Torque
! Years
! Comments
|-
| 22R
| {{convert|72|kW|hp PS|0|abbr=on}} at 4,800 rpm
| {{convert|174|Nm|lbft|0|abbr=on}} at 2,800 rpm
| 1981–1990
| carb, dual row timing chain ('81–'82)
carb, single row timing chain ('83–'90)
|-
| 22R
| {{convert|81|kW|hp PS|0|abbr=on}} at 5,000 rpm
| {{convert|187|Nm|lbft|0|abbr=on}} at 3,400 rpm
| 1990–1995
|
|-
| 22R-E
| {{convert|78|kW|hp PS|0|abbr=on}} at 4,800 rpm
| {{convert|185|Nm|lbft|0|abbr=on}} at 2,800 rpm
| 1983–1984
| EFI, single row timing chain
|-
| 22R-E
| {{convert|84|kW|hp PS|0|abbr=on}} at 4,800 rpm
| {{convert|190|Nm|lbft|0|abbr=on}} at 3,600 rpm
| 1985–1997
| EFI, single row timing chain
|-
| 22R-TE
| {{convert|101|kW|hp PS|0|abbr=on}} at 4,800 rpm
| {{convert|234|Nm|lbft|0|abbr=on}} at 2,800 rpm
| 1986–1988
| turbocharged, single row timing chain
|}

Applications:
* 22R
** 1981-1982 [[Toyota Corona]]
** 1981–1997 [[Toyota Hilux]]
** 1981–1984 [[Toyota Celica]]
** 1991 [[Toyota Cressida]]
** 1981–1995 [[Toyota Pickup]]
** 1984 [[Toyota 4Runner]]
** 1984–1989 [[Toyota Land Cruiser Prado#Predecessor (J70; 1984)|Toyota Land Cruiser II, Bundera]]
* 22R-E
** 1985–1995 [[Toyota Hilux]]
** 1983–1985 [[Toyota Celica]]
** 1983–1987 [[Toyota Corona (T140)|Toyota Corona]] RT142
** 1984–1995 [[Toyota Pickup]]
** 1985–1995 [[Toyota 4Runner]]
** 1989–1997 [[Volkswagen Taro]]
* 22R-TE
** late 1985–1988 [[Toyota Hilux]]
** 1986–1987 [[Toyota 4Runner]]

==References==
{{reflist}}

==See also==
{{commons category|Toyota R engines}}
* [[List of Toyota engines]]
* [https://web.archive.org/web/20100111044404/http://www.toysport.com/Technical%20Information/22r_tech_notes.htm 22R Tech Notes] (Toysport)
* [http://www.toyoland.com/engines/20R.html Toyota 20R engines: details and photos] (Toyoland)

[[Category:Toyota engines|R]]