GM 60-Degree V6 engine

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GM 60° V6 engine
LA1 3400 engine in a 2005 Pontiac Grand Am
ManufacturerGeneral Motors
Production1980–
SuccessorGM High Value engine

The General Motors 60° V6 family of engines began with the 1980 Chevrolet 2.8 L V6 and continues to be produced today (if one doesn't count a larger block casting with larger bore center and new cylinder heads). Its use in the X-body cars leads some to refer to it as the X engine.

It is a 60° vee block with pushrod heads, except for a single DOHC member, the LQ1. This engine family continues with the new GM High Value engine.

Generation I

The first generation of GM 60° V6 engines featured an iron block and heads with inline valves. This generation started in 1980 and versions were produced through 1996. Two different blocks were developed:

Transverse

The transverse engines began the 60° family in 1980. Like the rest of the Generation I engines, they were updated in 1985 with larger main journals for durability, along with multi-point fuel injection or E2SE carb and OBD I. Production of the Generation I transverse engines ended in 1986.

LE2

The 2.8 L LE2 was the first version of the 60° engine. It was a transverse version produced from 1980 through 1986 for the X-body cars. The standard ("X-code") engine for this line, it used a 2-barrel carburetor. Output was 115 hp for 1980 and '81 (86 kW), 112 hp for 1982-86 and 135 ft·lbf (183 N·m). Bore was 89 mm and stroke was 76 mm.

Applications:

LH7

Introduced in 1981, the 2.8 L LH7 was a High Output ("Z-code") version of the LE2 for the higher-performance X-cars like the Chevrolet Citation X-11. It still used a 2-barrel carburetor and produced 135 hp (100 kW) and 165 ft·lbf (224 N·m) for 1981 and 145 ft·lbf 197 N·m for 1982-1984 versions. The LH7 was replaced after 1984 with the MFI L44.

Applications:

L44

L44 in a 1988 Pontiac Fiero Formula

The L44 was produced from 1985 to 1988. It used MFI and was a High Output ("9-code") engine for the Pontiac Fiero. This engine created 140 hp (104 kW ) @ 5000 rpm and 160 ft·lbf (180 Nm) of torque @ 3600 rpm. It also used the same camshaft as the 3.4L V6 that was installed in later Camaros and Firebirds.

Applications:

LB6

The LB6 was produced from 1985 to 1986. It used electronic fuel injection and was a High Output ("W-code") transverse version. It produced 130 HP and 170 ft·lbf (230 N·m). torque.

Applications:

Longitudinal

The longitudinal versions were quite different from the transverse engines on which they were based. This group appeared in 1982 with the LC1 and LR2 and never added the aluminum heads of the Generation II engines.

Like the rest of the family, larger journals appeared in 1985, along with MPFI for the F-body LB8 version. TBI was added for the truck version in 1986.

A 3.1 L version was added in 1990 with an 8 mm longer stroke, and a 3.4 L appeared for 1993 with a 92 mm bore and SFI. Production of the 2.8 L and 3.1 L (Isuzu) engines ended in 1994. Production ended for all longitudinal 60° V6s in 1996, though GM's performance parts division continued production of a related crate engine after 1999.

LC1

The longitudinal LC1 was produced from 1982 to 1984. It was a 2-barrel High Output ("1-code") version for the F-body cars. Output was 102 hp (76 kW) and 145 ft·lbf (197 N·m). It was replaced by the LB8 for 1985.

Applications:

LR2

The longitudinal LR2 was a truck version ("B-code") produced from 1982 to 1990. It used a 2-barrel carburetor and produced 115 hp (86 kW) and 150 ft·lbf (203 N·m).

Applications:

LL1

The longitudinal LL1 was a high-output version of the LC1 produced in 1983 and 1984. It was an optional ("L-code") engine on the Pontiac Firebird with 125 hp (93 kW).

Applications:

LB8

The LB8 ("S-code") replaced the LC1 in 1985 and was produced until 1989. It used multi-port fuel injection and was made for longitudinal mounting. Output was 135 hp (101 kW) and 165 ft·lbf (224 N·m).

Applications:

LL2

The carbureted LL2 ("R-code") was produced from 1982 to 1983. Another LL2 ("R-code") with throttle body fuel injection was produced from 1986 to 1993.

Applications:

Generation II

The second generation, still 2.8 liters, was introduced in 1987. It used aluminum heads with splayed valves and an aluminum front cover. It was produced exclusively for transverse, front-wheel drive use.

The next year, Chevrolet introduced a full-production long-stroke 3.1 L (3136 cc, 191 CID) version, thanks to an 89 mm bore and 84 mm stroke. It was produced simultaneously with the 2.8L in various compact & midsized vehicles until 1990 when the 2.8L was dropped. MPFI was added to both, and a full-production turbo version was available on the 3.1L. An even higher displacement DOHC 3.4 L LQ1 was also developed and, eventually, the new GM High Value engine family followed. Production of Generation II engines ended in 1994 after the introduction of the Generation III in 1993.

The 2.8 L 60° V6 was used in the following vehicles:

Generation 2, 2.8L 60° V6 in a Buick Regal

The 3.1 L 60° V6 was used in the following vehicles:

LG6

The LG6 ("D-code") was produced from 1990 to 1996. It used throttle-body injection and iron heads. It produced 120 hp.

Applications:

LH0

The LH0 ("T-code") was introduced in 1988 on the Pontiac 6000 STE AWD. It featured a more exotic (for the time) multi-port fuel injection. While not known for its high RPM power, the LH0 has strong low- and mid-range torque. The 3.1 L engine has retained an excellent reputation for reliability. It was produced until 1996 and was exported in some models. This engine produced 135hp and 180lb/ft of torque from 1988-1989, then upgraded to 140hp and 185lb/ft of torque.

Uses:

LG5

The LG5 ("V-code") was a special 3.1 L turbocharged engine produced with McLaren for just two years, 1989 and 1990. It featured the same multi-port fuel injection intake manifolds and throttle body as the LH0, but cranked out 205 hp (153 kW) at 5200 rpm and 225 lb·ft (305 N·m) of torque at 2100 rpm. Approximately 3,700 engines were produced each year. This engine had a block with more nickel content and hardened internals.

This engine is notable, along with other GM turbo engines of the era (such as that found in the Typhoon/Syclone), for the ease with which significant performance gains can be realized with relatively pedestrian modifications.

Applications:

Generation III

The third generation of the 60° engine was introduced in the 1993 Oldsmobile Cutlass Supreme. It was still an iron block/aluminum head engine, but the head was redesigned for better air flow.

From the mid-1990s to 2003, some versions (the plastic intake manifold version) of this engine are involved in intake manifold gasket defects which caused coolant leakage often leading to engine failure. A series of class action lawsuits, implicating deterioration of the nylon/silicone material of the gasket & the heat warping of the plastic intake manifold upon exposure to Dexcool antifreeze, are pending on this issue. Tell-tale signs of such eventual related damage are a white foam that appears on the inside of the oil filler cap and the gradually increasing loss of antifreeze coolant (due to seepage into the intake passages which will lead to engine lock up failure in such cases). External seepage is also found near the valley edge of the lower intake manifold.

3.1L/3100

L82

The L82 ("M-code") was an updated, SFI version of the MPFI LH0, produced from 1993 through 1999. It featured a structural oil pan, a stiffer redesigned engine block, and sequential fuel injection. Output for this version was up 20 hp to 160 hp (up 15 kW to 118 kW) at 5200 rpm and 185 ft·lbf (250 N·m) at 4000 rpm. Compression Ratio for the L82 was 9.5:1 and the bore measured 89 mm (3.5 in) while the stroke was 84 mm (3.3 in) giving it a displacement of 191 CID (3,136 cc).

Applications:

LG8

The LG8 ("J-code") was a modern version of the 3.1 L engine that displaced 191 cubic inches (3,136 cc)[1], produced since model year 2000. It still had an iron block and 2-valve pushrod aluminum heads but now had full sequential port fuel injection. The LG8 also featured a new intake manifold and numerous changes to improve parts sharing with the offshoot GM High Value engine family. Emissions were improved with air injection for LEV status. Power was 170 hp-175 hp (127 kW to 131 kW) and torque was 190 ft·lbf–195 ft·lbf (258 N·m to 264 N·m). The LG8 was built in Ramos Arizpe, Coahuila, Mexico and Tonawanda, New York.

Applications:

3.4L/3400

GM produced three 3.4 L (204 CID/3,350 cc) variants of the 60° block: The L32, a normal large-bore OHV descendant of the 3.1 L (not to be confused with the 90° Series III L32 supercharged), the LA1, and a performance-oriented DOHC version, the LQ1.

L32

The power rating of the 3.4 L L32 ("S-code") used in the Camaro and Firebird was 160 hp (120 kW ) @ 4,600 rpm and 200 ft·lbf (270 Nm) torque @ 3600 rpm.

Applications:

LQ1

The LQ1 (also called the Twin Dual Cam or TDC) was a 3.4 L DOHC V6 motor ("X-code") based on the aluminum headed second generation of GM's 60° engine line, sharing a similar block with its pushrod cousins, the 3.1 L LH0 V6 and the then recently retired 2.8 L LB6 V6. The motor was built only for front wheel drive applications, and was featured exclusively in the first generation of GM's W-body platform.

It was built from 1991 to 1997. From 1991 to 1993, it used tuned multi-port fuel injection, made 200-210 HP (150-160 kW) @ 5200 RPM and 215 ft·lbf (290 Nm) of torque @ 4000 RPM. From 1994 to 1997, it used sequential port fuel injection, making 215 hp (160 kW) @ 5200 rpm and 225 ft·lbf (300 Nm) of torque @ 4000 rpm. It had four large valves per cylinder. The 3.4 L engine used a cogged belt to drive the four overhead camshafts. Adapting a pushrod block for the LQ1's overhead cams was difficult, and the 60° angle made this a very tall engine, but power output was impressive.

Bore was increased to 92 mm, but the 3.1 L engine's 84 mm stroke was retained. There are only a few interchangeable parts between this DOHC engine and other members of the 60° family, namely the connecting rods and crankshaft.

The heads and intake manifolds were redesigned for the 1996 model year, incorporating a larger throttle body and plenum area, slightly shorter intake runners, cloverleaf combustion chambers, and larger "pill"-shaped exhaust ports. Camshafts and cam timing were also revised for the new, higher RPM powerband.

Optional from 1991 to 1993 was a Getrag 284 5-speed manual transaxle, which was also exclusive to the GM W platform and was available only with the LQ1. The electronically controlled Hydramatic 4T60-E 4-speed automatic transaxle was the alternative, used during the entire production run.

Applications:

LA1

The LA1 3400 ("E-code") was a bored-out version of the 3100. It retained the OHV layout of the previous engine, and was first utilized on the 1996 U platform minivans and appeared in a car for the first time in the 1999 Pontiac Grand Am and Oldsmobile Alero. A 92 mm (3.6 in) bore with the same 84 mm (3.3 in) stroke brought the displacement to 3.4 L (3,350 cc/204 cu in). Like the LG8, the LA1 featured numerous common parts with the similar GM High Value engine family. Power was up to 170 hp-185 hp (127 kW to 138 kW) and torque was 210 ft·lbf (280 N·m). The 3.4 L engine is known to have intake manifold gasket problems causing engine damage if the owner of the car neglects to check or change the gaskets (if necessary). Many aftermarket companies have released gaskets that correct this problem for good. It is used in the following:

China

Production of the 60° family began in China with the success of the Buick marque there. Importation of Chinese-built engines to the United States began in 2004 with the LNJ found in the Chevrolet Equinox.

LB8

The LB8 is General Motors' base V6 in China. It is a derivative of the LG8 with the same 89 mm bore and a shorter 66.7 mm stroke for 2.5 L (2490 cc). It is still an iron block with pushrods and an aluminum 2-valve head. Power is 145 hp (108 kW) and 155 ft·lbf (210 N·m). It is built by Shanghai GM in Shanghai, China.

Applications:

LW9

The LW9 is a larger version of the LB8 with an 80 mm stroke for 3.0 L (2986 cc). Power is 170 hp (127 kW) and torque is 185 ft·lbf (251 N·m).

Applications:

LNJ

The 3.4 L LNJ is a 204-cubic-inch (3,350 cc) modified version of the normal 3400 engine. It includes a modified intake manifold, oil pan, engine cover, and fuel system as well as electronic throttle control. It is built in China and imported to Canada for use in the Chevrolet Equinox and Pontiac Torrent. The LNJ makes 185 hp (138 kW) and 210 lb·ft (285 N·m).[2]

See also

References

  • Road and Track Magazine, April 1989. (1989-1990 Turbo Grand Prix performance figures)
  • 1995 Corsica/Beretta Service Manual, 1994, General Motors Corporation (Gen III/L82 Engine's usage in Corsica/Beretta)

External links