Editing Buick V6 engine (section)

==Early versions==
===Fireball V6===
The first engine in this family, RPO code '''6I''', was introduced in 1961 for the 1962 model year [[Buick Special]] with Buick's {{cvt|198|cuin|L|1}} engine, the first V6 in an American car (the [[GMC V6 engine|GMC V6]] was used earlier in trucks). Because it was derived from Buick's {{cvt|215|cuin|L|1}} [[Buick V8 engine#215|aluminum V8]], it has a 90° bank between cylinders and an [[V6#CITEREF2008|uneven firing pattern]] due to the crankshaft having only three crank pins set at 120° apart, with opposing cylinders (1-2, 3-4, and 5-6) sharing a crank pin in, as do many V8 engines. The uneven firing pattern was often perceived as roughness, leading a former American Motors executive to describe it as "rougher than a cob."

The off-center design continued up until the 1988 LN3 version of the engine, when the left-hand bank of cylinders was moved forward relative to the right-hand bank. Although the actual bore spacing between cylinders on the same bank remained unchanged at {{cvt|4.24|in|mm}}, the LN3 and later engines became known to have "on-center bore spacing".

====198====<!-- This section is linked from [[V6 engine]] -->
The [[Buick]] Division, concerned about high manufacturing costs of their innovative aluminum 215 V8, sought to develop a cheaper, cast-iron engine based on the same tooling. It was given the RPO code '''JL'''. They settled on an unusual 90° [[V6]] layout that was essentially the architecture of the '215' less two cylinders. In initial form, it had a bore and stroke of {{cvt|3.625x3.1875|in|mm}}, for an overall displacement of {{cvt|3234.5|cc|CID L cc|1|adj=ri0|order=out}}. It weighed about {{cvt|35|lb|kg}} more than the aluminum engine, but was far cheaper to produce. Dubbed the '''Fireball''' V6, it became the standard engine in the 1962 [[Buick Special]]. In their test that year, ''[[Road & Track]]'' was impressed with Buick's "practical" new V6, saying it "sounds and performs exactly like the aluminum V8 in most respects."

====225====
The bore was increased to {{cvt|3.75|in|mm|2}}, and stroke increased to {{cvt|3.4|in|mm|1}}, increasing displacement to {{cvt|3692|cc|CID L cc|1|adj=ri0|order=out}}. Since the engine was similar to the popular small-block Buick V8—now with a cast-iron block and displacement of {{cvt|300|cuin|L|1}}, the engine was made cheaply at the same factory with much of the same tooling. This engine carried the RPO code '''KH''' for the 1964 model year and '''LH''' for 1965. In 1966, the code was '''MH''' and was renamed the ''Wildcat V-6''.  For 1967, the code was '''NH'''. This engine was used in Buick's intermediate-sized Special and Skylark models from 1964 to 1967 and Oldsmobile's mid-sized F-85/Cutlass models for 1964 and 1965, including the Oldsmobile Vista Cruiser and Buick Sport Wagon.

1964–1965 models featured a single barrel Rochester MonoJet, producing {{cvt|155|hp|kW|0}}. In 1966–1967, the 1-barrel was replaced with a 2-barrel Rochester 2GV, giving the engine a 5-horsepower boost to {{cvt|160|hp|kW|0}}.

The V6 was dropped after the 1967 model year in favor of a conventional {{cvt|250|cuin|L|1}} [[inline-six engine]] built by the [[Chevrolet]] division, and the tooling was sold to [[Kaiser-Jeep]].

====Dauntless====
In 1965, [[Kaiser-Jeep]] began using the Buick 225 in [[Jeep CJ]]s. It was known as the '''Dauntless V6''' and used a much heavier flywheel than the Buick version to damp the vibrations resulting from the engine's firing pattern. Buick sold the tooling for this engine to Kaiser in 1967, as the demand for the engine was waning steadily in an era of V8s and [[muscle car]]s. When [[American Motors Corporation|American Motors]] (AMC) bought Jeep, the V6 was replaced with [[AMC Straight-6 engine|AMC straight-6 engine]]s, but the ownership of the V6 tooling remained with AMC.

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* 1966–1971 [[Jeep Jeepster]] & [[Jeepster Commando]]
* 1966–1971 [[Jeep CJ#CJ-5|CJ-5]]
* 1966–1971 [[Jeep CJ#CJ-6|CJ-6]]
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====231====<!-- This section is linked from [[V6 engine]] -->
The [[1973 oil crisis]] prompted GM to look for more economical engines than the V8s of 350, 400, and 454/455 cubic inches that powered most General Motors cars and trucks during that time. At that time, the only "small" engines generally offered by GM were built by the Chevrolet division including the {{cvt|140|cuin|L|1}} [[OHC]] aluminum [[inline-four engine]] used in the subcompact [[Chevrolet Vega]] and a [[Chevrolet Turbo-Thrift engine#250|{{cvt|250|cuin|L|1}} straight-6]] used in smaller Chevy, Buick, Oldsmobile and Pontiac models, whose design roots dated back to the 1962 Chevy II (Nova). '''LD5''' was the RPO for engines with chassis code "A", '''LD7''' was used for the 1977-only VIN code "C" engines.

One quick idea was tried by Buick engineers—taking an old Fireball V6 picked up at a junkyard and installing it into a 1974 Buick Apollo. The solution worked so well that GM wanted AMC to put the engine back into production. However, AMC's cost per unit was deemed as too high. Instead of buying completed engines, GM made an offer to buy back the tooling and manufacturing line from AMC in April 1974, and began building the engines on August 12.<ref>{{cite book |title=Ward's Automotive Yearbook 1975 |year=1975 |publisher=Ward's Communications, Inc.}}</ref> With production back within GM, Buick re-introduced the V6 that fall in certain 1975 models—a move made possible by the fact that foundations for the old V6 machinery were still intact at Buick's engine assembly plant in Flint, Michigan, so it was easy to put the old tooling back in place and begin production at least two years ahead of the normal schedule that would have been required to create new tooling. The bore was enlarged to {{cvt|3.8|in|mm}}, identical to the [[Buick V8 engine#350|Buick 350]] and [[Oldsmobile V8 engine#307|Olds 307]] V8s, yielding {{cvt|3791.3|cc|CID L cc|1|adj=ri0|order=out}} displacement. 78,349 units were installed in Buicks for 1975.<ref>{{cite book |title=Ward's Automotive Yearbook 1976 |year=1976 |publisher=Ward's Communications, Inc.}}</ref>

Due to difficulties with the new fuel economy and emissions standards, the engine produced just {{cvt|105|or|110|hp|kW|0}}, depending on fitment and year.

In 1977, Buick redesigned the crankshaft to a "split-pin" configuration to create an "even-firing" version. The crank pins associated with the opposing cylinders were offset from each other by 30°. The relatively small offset did not require flying arms to be incorporated, however a {{cvt|3|mm}} thick flange was built in between the offset crank pins to prevent the connecting rod big-ends from "walking" off the crank pin bearing journal and interfering with the adjacent big end. The {{cvt|3|mm}} thick flange effectively caused the connecting rods on the left-hand bank of cylinders (forward bank for FWD applications) to move {{cvt|1.5|mm}} forward and the right-hand bank to move {{cvt|1.5|mm}} rearward, but the engine block remained unchanged compared to the odd-fire engine. Since the cylinders center-lines were no longer centralized over the crank pin bearing journals, the connecting rods were re-designed with the big-ends offset from the piston pin ends by {{cvt|1.5|mm}}. The engine in this configuration became known to have "off-center bore spacing".

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* 1975      [[Buick Apollo]]
* 1975–1980 [[Buick Skyhawk]]
* 1975–1977 [[Buick Century]]
* 1975–1977 [[Buick Regal]]
* 1975–1976 [[Buick LeSabre]]
* 1975–1979 [[Buick Skylark]]
* 1975–1982 [[Oldsmobile Cutlass]]
* 1978–1981 [[Chevrolet Camaro]]
* 1978–1987 [[Chevrolet El Camino]]
* 1978–1983 [[Chevrolet Malibu]] Both the {{cvt|229|CID|L|1}} engine used in the Malibu starting in 1980 and the {{cvt|200|CID|L|1}} version first used in 1978 were NOT versions of the Buick 3800 Engine, but a different Chevy-built engine. Both the Buick V6 and the {{cvt|229|cid|L|1}} Chevrolet V6 are 90-degree V6 engines, and both are often referred to as being a 3.8 L V6. These engines should not be confused as being the same, and are unique engine designs. The {{cvt|229|CID|L|1}} Chevrolet V6 was essentially a small block Chevy V8 missing two cylinders. 
* 1978–1987 [[Chevrolet Monte Carlo]] This is very confusing, as Monte Carlo at various times used both the V6 from the Buick engine as well as the V6 engine derived from the Chevrolet V8.
* 1978–1980 [[Chevrolet Monza]]
* 1978–1987 [[Oldsmobile Cutlass Supreme]]
* 1975–1980 [[Oldsmobile Starfire]]
* 1977–1979 [[Oldsmobile Omega]]
* 1978–1987 [[Pontiac Grand Prix]]
* 1976–1980 [[Pontiac Sunbird]]
* 1976–1981 [[Pontiac Firebird]]
* 1978–1981 [[Pontiac LeMans]]
* 1977–1979 [[Pontiac Ventura]]
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====LD5====
[[File:1978 Buick 3.8 litre turbo engine in a Regal.jpg|thumb|The original, carbureted turbocharged LD5 from a 1978 Regal Sport [[Coupé]]]]
In 1978, GM began to market the 231 as the '''3.8 liter''' as [[metric engine (American expression)|metric engine]] sizes became common in the [[United States]]. The ''[[Regular Production Option|RPO Code]]'' was '''LD5''', though California-emissions versions were called '''LC6'''. Starting in 1979, the engine was used in the [[front-wheel drive]] [[Buick Riviera]], though still with a longitudinal mounting. Larger valves and better intake and exhaust boosted the power output for 1979.

A [[turbocharged]] version was introduced as the pace car at the 1976 [[Indianapolis 500]], and a production turbo arrived in 1978. The turbo 3.8 received [[sequential fuel injection]] and a [[wasted spark]] [[Distributorless Ignition System]] in 1984. In 1986, an air-to-air [[Garrett AiResearch|Garrett]] [[intercooler]] was added and the ''RPO Code'' became ''LC2''. The LC2 engine has a [[Bore (engine)|bore]] and [[Stroke (engine)|stroke]] of {{cvt|3.8x3.4|in|1}}. The [[horsepower]] ratings for 1986 & 1987 were {{cvt|235|and|245|hp|PS kW|0}}, respectively. The limited production GNX benefitted from additional factory modifications such as a [[ceramic]] turbocharger, more efficient Garrett intercooler, low restriction [[exhaust system]] and revised programming which resulted in a {{cvt|300|hp|PS kW|0}} factory rating.

The turbocharged 1987 Buick Regal Grand National GNX was called America's quickest automobile, and the model continues to be collected and appreciated today.

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* 1978–1987 [[Buick Regal#Grand National, Turbo-T and T-Type|Buick Regal Sport Coupe, T-Type, Grand National, and GNX]]
* 1978–1980 [[Buick LeSabre]] Sport Coupe
* 1979–1980 [[Buick Century]] Turbo Coupe & Sedan
* 1979–1985 [[Buick Riviera]] S-Type, T-Type and less than 100 Convertibles
* 1980–1981 [[Chevrolet Monte Carlo]] Turbo
* 1989 [[Pontiac Firebird Trans Am|Pontiac Trans Am Turbo]] ''20th Anniversary Edition''
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====LC9====
A smaller version of this engine was produced in 1978 and 1979 for the Century, Regal, and [[Chevrolet Monza]]. The bore was reduced to {{cvt|3.5|in|mm|1}}, resulting in an engine of {{cvt|3216.3|cc|CID L cc|1|adj=ri0|order=out}} piston displacement. The ''RPO code'' was ''LC9''. Initially this engine produced {{cvt|90|hp|0}}, but in 1979 it received the same improvements in the cylinder heads as did the LD5, and therefore power increased to {{cvt|105|hp|0}}.

====LC4====
In response to rising gas prices, a larger {{cvt|4128|cc|CID L cc|1|adj=ri0|order=out}} version of the 3.8 liter LD5 V6 was produced from 1980 through 1984 and marketed as an alternative to a V8. The bore was enlarged to {{cvt|3.965|in|mm}}, yielding an output of {{cvt|125|hp|0}} and {{cvt|205|lbft|Nm|0}}. This engine was used in many large [[rear-wheel drive]] Buicks, and in some models from each of GM's other divisions, including Cadillac which offered the "big" Buick V6 in several models from 1980 to 1982 as a credit option to the troublesome [[Cadillac V8 engine#368 and V8-6-4|V8-6-4]] engine used in 1981 and early versions of the aluminum-block Cadillac [[Cadillac V8 engine#HT-4100|HT-4100]] V8 introduced in 1982. It was also the standard powerplant in the front-drive [[Buick Riviera|Riviera]] and [[Oldsmobile Toronado]] from 1981 to 1984. Additionally, the 4.1 block was used unsuccessfully at Indianapolis for racing. Its only weakness was the intake valve seals.{{citation needed|date=November 2024}} This was the first naturally aspirated GM V-6 to feature a 4-barrel carburetor.
{| class=wikitable
!Year
!Horsepower
!Torque
!Fuel System
!Compression Ratio
!VIN Code
|-
|1980–1984|| {{cvt|125|hp|0}} at 4,000&nbsp;rpm||{{cvt|205|lbft|Nm|0}} at 2,000&nbsp;rpm||4-bbl||8.0:1||4
|}

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* 1980–84 [[Buick Electra#Fifth generation (1977–1984)|Buick Electra]]
* 1980–84 [[Buick LeSabre#1977|Buick LeSabre]]
* 1982–84 [[Buick Regal#Second generation (1978)|Buick Regal]]
* 1981–84 [[Buick Riviera#Sixth generation (1979–1985)|Buick Riviera]]
* 1980–82 [[Cadillac Deville#1977 - 1984|Cadillac DeVille]]
* 1981–82 [[Cadillac Eldorado#Tenth generation (1979–1985)|Cadillac Eldorado]]
* 1980–82 [[Cadillac Fleetwood#1977–1986 .28RWD.29|Cadillac Fleetwood]]
* 1981–82 [[Cadillac Seville#Second generation (1980–1985)|Cadillac Seville]]
* 1981–83 [[Oldsmobile 98#1977|Oldsmobile 98]]
* 1981–84 [[Oldsmobile Toronado#Third generation.2C 1979.E2.80.9385|Oldsmobile Toronado]]
* 1982 [[Pontiac Grand Prix#1978|Pontiac Grand Prix]]
* 1982 [[Pontiac Bonneville#Seventh generation (1982–1986)|Pontiac Bonneville]]
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==== LK9 ====
A small {{cvt|2966|cc|CID L cc|1|adj=ri0|order=out}} version of the Buick V6 was produced for GM's 1980s [[front-wheel drive]] cars. Introduced in 1982, it was a lower deck version of the 3.8 designed for [[transverse engine|transverse]] application in the new [[GM A platform]] cars such as the [[Buick Century]] and [[Oldsmobile Cutlass Ciera]]. It shared the same bore size as its larger sibling, but featured a smaller stroke of {{cvt|2.66|in|mm}}. It used a [[Rochester Products Division|Rochester]] E2ME 2-bbl [[carburetor]] and the [[VIN]] code for the engine is ''E''.

{| class=wikitable
!Year
!Horsepower
!Torque
!Compression Ratio
|-
|1982–1983||rowspan=2| {{cvt|110|hp|0}} at 4,800&nbsp;rpm||{{cvt|145|lbft|Nm|0}} at 2,000&nbsp;rpm||8.45:1
|-
|1984–1985||{{cvt|145|lbft|Nm|0}} at 2,600&nbsp;rpm||8.4:1
|}

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* 1982–1985 [[Buick Century#1982|Buick Century]]
* 1982–1985 [[Oldsmobile Cutlass Ciera]]
* 1985 [[Oldsmobile 98]]
* 1985 [[Buick Electra]]
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==== LN7 ====
The '''LN7''' is a [[Multi-point injection|multiport fuel injected]] version of the '''LK9'''. It was introduced for 1985 and used the [[VIN]] code: '''L'''. It was replaced in 1989 with the 3.3.

{| class=wikitable
!Horsepower
!Torque
!Compression Ratio
|-
|{{cvt|125|hp|0}} at 4,900&nbsp;rpm||{{cvt|150|lbft|Nm|0}} at 2,400&nbsp;rpm||9.0:1
|}

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* 1986 [[Oldsmobile Delta 88]]
* 1986 [[Buick LeSabre]]
* 1986–1988 [[Buick Skylark]]
* 1985–1987 [[Buick Somerset]]
* 1985–1987 [[Pontiac Grand Am]]
* 1985–1988 [[Oldsmobile Cutlass Calais]]
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===={{anchor|LG2|LG3}}3.8 FWD LG2/LG3====
In mid-1984, the 3.8 liter [[#LD5|LD5 engine]] was modified for transverse-mounting in smaller, [[front-wheel drive|FWD]] vehicles, and equipped with multi point fuel injection (MPFI). 1984-1985 models used a distributor and a distributorless [[wasted spark]] ignition system was added for all engines produced in 1986 and later. In 1986, it received sequential fuel injection (SFI) and it was initially produced in two forms, the LG2 with flat lifters (tappets), and the LG3 with a roller camshaft and lifters. The latter was offered in various models through 1988. From 1986, the 3.8 had a revised, crankshaft-driven oil pump which eliminated a longstanding problem with pump housing wear and loss of prime. Power produced by this engine was:
* VIN code B (LG2): flat lifters (tappets)
** {{cvt|140|hp|kW|0}} at 4,400&nbsp;rpm, {{cvt|200|lbft|Nm|0}} at 2,000&nbsp;rpm
* VIN code 3 (LG3): roller lifters (tappets)
** {{cvt|125|hp|kW|0}} at 4,400&nbsp;rpm, {{cvt|195|lbft|Nm|0}} at 2,000&nbsp;rpm (1984–1985 MPFI)
** {{cvt|150|hp|kW|0}} at 4,400&nbsp;rpm, {{cvt|200|lbft|Nm|0}} at 2,200&nbsp;rpm (1986–1988 SFI)
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*1984–1988 Buick Century
*1986 Buick Riviera (LG2)
*1987 Buick Riviera (LG3)
*1986–1987 [[Buick Lesabre#Sixth generation .281986.E2.80.931991.29|Buick LeSabre]]
*1985–1987 [[Buick Electra]]
*1984–1988 Oldsmobile Cutlass Ciera
*1986–1987 [[Oldsmobile 88#1986.E2.80.931991|Oldsmobile Delta 88]]
*1985–1987 Oldsmobile Ninety Eight
*1986–1987 Oldsmobile Toronado
*1987–Early 1988 Pontiac Bonneville
{{hidden end}}