The
Chevrolet
Chevrolet ( ) is an American automobile division of the manufacturer General Motors (GM). In North America, Chevrolet produces and sells a wide range of vehicles, from subcompact automobiles to medium-duty commercial trucks. Due to the promi ...
90° V6 family of
V6 engine
A V6 engine is a six- cylinder piston engine where the cylinders and cylinder blocks share a common crankshaft and are arranged in a V configuration.
The first V6 engines were designed and produced independently by Marmon Motor Car Company, ...
s began in 1978 with the Chevrolet as the base engine for the all new 1978
Chevrolet Malibu
The Chevrolet Malibu is a mid-size car that was manufactured and marketed by Chevrolet from 1964 to 1983 and from 1997 to 2025. The Malibu began as a trim-level of the Chevrolet Chevelle, becoming its own model line in 1978. Originally a rear-w ...
. The original engine family was phased out in early 2014, with its final use as the V6 engine used in Chevrolet and
GMC trucks and vans. Its phaseout marks the end of an era of
Chevrolet small-block engine The Chevrolet small-block engine refers to one of the several Gasoline engine, gasoline-powered vehicle engines manufactured by General Motors. These include:
* The first or second generation of Chevrolet small-block engine (first- and second-gener ...
designs dating back to the 1955
model year
The model year (sometimes abbreviated as MY) is a method of describing the version of a product which has been produced over multiple years. The model year may or may not be the same as the calendar year in which the product was manufactured.
...
. A new Generation V V6 variant entered production in late 2013, based on the
LT1 small block V8 and first used in the 2014
Silverado/Sierra 1500 trucks.
Generation I
These engines have a 90° V-block with twelve valves activated by a
pushrod
A valvetrain is a mechanical system that controls the operation of the intake and exhaust valves in an internal combustion engine. The intake valves control the flow of air/fuel mixture (or air alone for direct-injected engines) into the combu ...
valvetrain. All engines have cast iron blocks and cylinder heads. The engines are based on the
Chevrolet Small-Block engine The Chevrolet small-block engine refers to one of the several Gasoline engine, gasoline-powered vehicle engines manufactured by General Motors. These include:
* The first or second generation of Chevrolet small-block engine (first- and second-gener ...
, and the V6 is formed by the removal of the #3 and #6 cylinders. The V6s share the same bore spacing and deck height as the
V8 engine
A V8 engine is an eight- cylinder piston engine in which two banks of four cylinders share a common crankshaft and are arranged in a V configuration.
Origins
The first known V8 was the Antoinette, designed by Léon Levavasseur, a ...
s. Many parts are interchangeable between the 90° V6 and the small block V8 including valvetrain components, some bearings, piston assemblies, lubrication and cooling system components, and external accessories.
The 90° V6 engine uses the same transmission bellhousing pattern as the Chevrolet small-block V8 engine. The oil pan dipstick is located on the passenger side above the oil pan rail; this design was phased in on both the 90° V6 and Small Block Chevrolet assembly lines (for engines manufactured after 1979) sharing the same casting dies. All the engines use a 1-6-5-4-3-2
firing order
The firing order of an internal combustion engine is the sequence of ignition for the cylinders.
In a spark ignition (e.g. gasoline/petrol) engine, the firing order corresponds to the order in which the spark plugs are operated. In a diesel engi ...
.
The engines in this family are
longitudinal engine
In automotive engineering, a longitudinal engine is an internal combustion engine in which the crankshaft is oriented along the long axis of the vehicle, from front to back.
See also: transverse engine
Use
This type of motor is usually used fo ...
s, and have been used in
rear-wheel drive
Rear-wheel drive (RWD) is a form of engine and transmission layout used in motor vehicles, in which the engine drives the rear wheels only. Until the late 20th century, rear-wheel drive was the most common configuration for cars.
Most rear-whee ...
cars and trucks, industrial, and marine applications. Until 2014, the Chevrolet 90° V6 was produced at the
GM Powertrain
This list of GM engines encompasses all engines manufactured by General Motors and used in its cars.
Divisions
When General Motors was created in 1908, it started out with Buick and soon after acquired Oldsmobile, Cadillac and Oakland. There were ...
Division plant in
Romulus, Michigan
Romulus is a city in Wayne County, Michigan, Wayne County in the U.S. state of Michigan. The population was 23,989 at the 2010 United States Census, 2010 census. Romulus is a western suburb of Metro Detroit and is also considered part of the Dow ...
.
3.3L (200 CID)
Introduced in 1978, the replaced the larger
as the base engine for Chevrolet's new downsized intermediate line. The used a unique bore and stroke (the Chevrolet V8 engines shared the same stroke dimension). These bore and stroke dimensions were later used by the
V8 Chevrolet engine. Also like the small block V8 engines, the V6 used
main bearing
A main bearing is a bearing in a piston engine which holds the crankshaft in place and allows it to rotate within the engine block.
The number of main bearings per engine varies between engines, often in accordance with the forces produced b ...
s and rod bearing diameters.
Being a 90° V6, Chevrolet took steps to eliminate the rough running tendencies of the 200. The
crankshaft
A crankshaft is a mechanical component used in a reciprocating engine, piston engine to convert the reciprocating motion into rotational motion. The crankshaft is a rotating Shaft (mechanical engineering), shaft containing one or more crankpins, ...
has each of its
connecting rod
A connecting rod, also called a 'con rod', is the part of a reciprocating engine, piston engine which connects the piston to the crankshaft. Together with the crank (mechanism), crank, the connecting rod converts the reciprocating motion of the p ...
throws offset by 18 degrees for each pair of rods. This required the connecting rods to have narrower ends as well as a thrust bearing to be installed between each pair of rods. However, the connecting rods were still the same length as most other small-block Chevrolet V8 engines. This produced an engine with a semi-even fire sequence of 132 degrees/108 degrees.
The V6 was only produced for 1978 and 1979. It was available only with a 2-barrel
carburetor
A carburetor (also spelled carburettor or carburetter)
is a device used by a gasoline internal combustion engine to control and mix air and fuel entering the engine. The primary method of adding fuel to the intake air is through the Ventu ...
. In 1978, the used the
Rochester 2GC carburetor and in 1979 it used a Rochester Dualjet carburetor. The smaller Dualjet carburetor caused a slight decrease in power.
3.8L (229 CID)
The engine was first introduced for the 1980 model year. This engine replaced the
straight-six in full-size
Chevrolet
Chevrolet ( ) is an American automobile division of the manufacturer General Motors (GM). In North America, Chevrolet produces and sells a wide range of vehicles, from subcompact automobiles to medium-duty commercial trucks. Due to the promi ...
s and
Camaros as the base six-cylinder engine. Additionally, the intermediate Chevrolet Malibu and Monte Carlo also used the as a replacement for both the V6 and the
Buick V6.
Checker Motors Corporation
Checker Motors Corporation was a vehicle manufacturer, and later an automotive subcontractor, based in Kalamazoo, Michigan. The company was established by Morris Markin in 1922, created by a merger of the firms Commonwealth Motors and Markin ...
also used this engine starting with its 1980 A11 Taxi and A12
Marathon
The marathon is a long-distance foot race with a distance of kilometres ( 26 mi 385 yd), usually run as a road race, but the distance can be covered on trail routes. The marathon can be completed by running or with a run/walk strategy. There ...
sedans. Both the Buick V6 and the Chevrolet V6 are 90° V6 engines, and are often referred to as the 3.8L V6. These engines should not be confused as being the same, and are unique engine designs.
The has a bore and stroke, identical to the Chevrolet V8 engine. The used the same main bearing and rod bearing diameters as the V6 engine. Also like the V6, the used the same crankshaft with the 18-degree offset throws and the same connecting rods with narrowed ends. It came equipped with intake valves and exhaust valves. The V6 was only equipped with a 2-barrel carburetor. For 1980, the used a mechanical Dualjet. From 1981 to 1984, the electronic Dualjet was used along with the GM's CCC (Computer Command Control) system. The was rated between 110 and .
4.3L (262 CID)
The V6 is the last and most successful engine in the Chevrolet 90° V6 engine family. This engine was introduced in 1985 as a replacement for the V6 in the full-size Chevrolet, the
Chevrolet El Camino
The Chevrolet El Camino is a coupé utility vehicle that was produced by Chevrolet between 1959–1960 and 1964–1987. Unlike a standard pickup truck, the El Camino was adapted from the standard two-door Chevrolet station wagon platform and in ...
, and
Chevrolet Monte Carlo
The Chevrolet Monte Carlo is a two-door coupe that was manufactured and marketed by the Chevrolet division of General Motors. Deriving its name from the Monte Carlo, city in Monaco, the Monte Carlo was marketed as the first personal luxury car ...
. It also replaced the
in the Chevrolet and GMC
full-size trucks and
full-size vans, and in 1990, it replaced the
292 cu in (4.8 L) in the
Step-Vans as the new base six-cylinder engine.
4
The V6 has a bore and stroke, identical to the Chevrolet V8 engine. To create a true even-fire engine, Chevrolet produced a crankshaft with 30-degree offsets between each rod pin. Consequently, rod journals were increased to a larger . The connecting rods used on the are therefore unique to this engine, being in length, but having the larger journals. The also used larger valves than the V6, with a intake valve and a exhaust valve (also shared with the 350).
In 1986 and 1987, the engine saw engine design upgrades similar to the Chevrolet small block V8. In 1986, the rear main crankshaft oil seal was changed from a two piece to a one piece seal. Some 1985 model year vehicles would have a 1986 engine due to service replacement – cylinder blocks were shipped with oil pans.
1987 saw new center bolt valve covers and hydraulic roller lifters.
For the 1992 model year, the had its block design modified to allow a
balance shaft
Balance shafts are used in piston engines to reduce vibration by cancelling out unbalanced dynamic forces. The counter balance shafts have eccentric weights and rotate in the opposite direction to each other, which generates a net vertical force ...
to be installed.
Even though the is an even-fire V6, the 90° block layout is not ideal for smoothness. The balance shaft on the is installed above the camshaft and runs through the middle of the lifter valley. It is gear-driven off the camshaft timing sprocket, and therefore, a new timing chain cover was required for these balanced 4.3L V6s. Balance shaft engines do not have provisions for a mechanical fuel pump, unlike the non-balance shaft engines which retained the cast-in boss.
For the 2007 model year, the distributor was eliminated in place of a
coil-on-plug ignition
An ignition coil is used in the ignition system of a spark-ignition engine to transform the battery voltage to the much higher voltages required to operate the spark plug(s). The spark plugs then use this burst of high-voltage electricity to ig ...
system (using a 58x crankshaft position sensor based on the GEN IV LSx). This resulted in a redesigned timing cover with a wider bottom flange, making it incompatible with the 1996–06 LU3/L35. The only vehicles using the new revision of the were the half-ton versions of the Chevrolet Silverado/GMC Sierra (2007–2013) and Chevrolet Express/GMC Savana (2008–2014).
LB1 and LB4
In 1985, the was either equipped with
throttle-body fuel injection (
RPO LB4) or a Rochester
Quadrajet four-barrel carburetor (RPO LB1). The Chevrolet Caprice, Chevrolet Monte Carlo,
Chevrolet El Camino
The Chevrolet El Camino is a coupé utility vehicle that was produced by Chevrolet between 1959–1960 and 1964–1987. Unlike a standard pickup truck, the El Camino was adapted from the standard two-door Chevrolet station wagon platform and in ...
, Pontiac Parisienne, and Pontiac Grand Prix used the LB4 rated at . Pickups and vans used the LB1 version rated at . The LB1 used in trucks and vans was referred to as Vortec in Chevrolet literature (named after a combustion chamber design known as a swirl port which twists the fuel mix from the intake ports as introduced with the Cavalier's 2.0L engine), and this name continued to be used with all truck and van V6s until 2014.
In 1986, the engine used in passenger cars saw an increase in power to . This engine remained unchanged until 1990 when it was last used in taxi (RPO 9C6) and police (RPO 9C1) Chevrolet Caprices. In 1986, the Chevrolet Astro and GMC Safari vans used the fuel-injected LB4 instead of the LB1. In 1987, the Chevrolet full-size pickups and vans were upgraded to use the LB4 throttle-body injection version of the . The mechanical fuel pump boss was retained but the hole was undrilled (marine applications had the fuel pump boss drilled and tapped). From 1987 onwards, the LB4's output was for pickups, while full-size vans were rated at . In 1988, the S-10/S-15 trucks, S-10 Blazer, and S-15 Jimmy had the LB4 as an available option (the accessory drive was upgraded to a serpentine belt drive), which later replaced the 2.8L as the base V6. The LB4 continued until 1996 with minor variations in power, but without any major changes. While a majority of LB4s did not have a balance shaft, some 1994 model year engines may have a balance shaft since production of the cylinder block used on the L35 was phased in for both induction systems. The 1994 model year was the final time a non-balance shaft cylinder block was used; production 1995 TBI engines were all balance-shaft engines.
Legend
* 1 –
Chevrolet C/K
The Chevrolet C/K is a series of trucks that was manufactured by General Motors from the 1960 to 2002 model years. Marketed by both the Chevrolet and GMC divisions, the C/K series encompassed a wide range of vehicles. While most commonly associat ...
trucks,
GMC C/K trucks
* 2 –
Chevrolet G-series vans, GMC G-Series vans
* 3 –
Chevrolet Astro
The Chevrolet Astro is a minivan that was manufactured and marketed by the Chevrolet division of American auto manufacturer General Motors from 1985 to 2005. Sold alongside the GMC Safari, the Astro was marketed in multiple configurations, incl ...
vans,
GMC Safari vans (Note: LB1 for 1985 only and LB4 not available 1995)
* 4 – 1985
Chevrolet Impala
The Chevrolet Impala () is a full-size car that was built by Chevrolet for model years 1958 to 1985, 1994 to 1996, and 2000 to 2020. The Impala was Chevrolet's popular flagship passenger car and was among the better-selling American-made auto ...
, 1985–1988
Chevrolet Caprice
The Chevrolet Caprice is a full-size car produced by Chevrolet in North America for the 1965 through 1996 model years. Full-size Chevrolet sales peaked in 1965, with over a million units sold. It was the most popular car in the U.S. in the 19 ...
, 1989–1990 Chevrolet Caprice police/taxi only, 1985–1986
Pontiac Parisienne
The Pontiac Parisienne is a full-size rear-wheel drive vehicle that was sold by Pontiac on the GM B platform in Canada from 1958 to 1986 and in the United States from 1983 to 1986. Right-hand drive models were locally assembled in Australia, New ...
* 5 – 1985–1988
Chevrolet El Camino
The Chevrolet El Camino is a coupé utility vehicle that was produced by Chevrolet between 1959–1960 and 1964–1987. Unlike a standard pickup truck, the El Camino was adapted from the standard two-door Chevrolet station wagon platform and in ...
,
GMC Caballero,
Chevrolet Monte Carlo
The Chevrolet Monte Carlo is a two-door coupe that was manufactured and marketed by the Chevrolet division of General Motors. Deriving its name from the Monte Carlo, city in Monaco, the Monte Carlo was marketed as the first personal luxury car ...
, 1986–1987
Pontiac Grand Prix
The Grand Prix is a line of automobiles produced by the Pontiac (automobile), Pontiac Division of General Motors from 1962 until 2002 as coupes and from 1989 through 2008 model years as four-door sedans.
First introduced as a full-size car, full ...
(Note: LB4 used 1986 only)
* 6 – 1988–1994
Chevrolet S-10 Blazer
The Chevrolet (S-10) Blazer and its badge engineered GMC (S-15) Jimmy counterpart are compact/mid-size SUVs manufactured and marketed by Chevrolet and GMC from the 1983 through 2005 model years, over two generations – until the early 1990s a ...
,
GMC S-15 Jimmy
GMC may refer to:
Government India
* Gandhinagar Municipal Corporation, in Gujarat
* Gobichettipalayam Municipal Corporation, in Tamil Nadu
* Guntur Municipal Corporation, in Andhra Pradesh
* Guwahati Municipal Corporation, in Assam
* Gwalior ...
, and 1991
Oldsmobile Bravada
* 7 – 1988–1995
Chevrolet S-10
The Chevrolet S-10 is a compact pickup truck produced by Chevrolet. It was the first domestically-built compact pickup of the big three American automakers. When it was first introduced as a "quarter-ton pickup" in 1981 for the 1982 model year, ...
and
GMC S-15/Sonoma
LU2
For the 1990–1991 model years, a high-output V6 was an available option for the extended-length versions of the Chevrolet Astro and GMC Safari vans. The LU2 used unique
hypereutectic, strutless pistons and a more aggressive camshaft. Like the LB4, the LU2 used throttle-body fuel injection, but was rated at and of torque. This engine was replaced in 1992 with the L35.
Legend
* 1 –
Chevrolet Astro
The Chevrolet Astro is a minivan that was manufactured and marketed by the Chevrolet division of American auto manufacturer General Motors from 1985 to 2005. Sold alongside the GMC Safari, the Astro was marketed in multiple configurations, incl ...
vans,
GMC Safari vans; optional on extended-length models only
L35 CPI
1992 introduced a new version of the , the L35. This version of the was equipped with CPI (Central Port Fuel Injection). This system had one centrally-located fuel injector to distribute fuel to six hoses each with a poppet valve to each of the intake ports. This system allowed for a
multi-point fuel injection
Fuel injection is the introduction of fuel in an internal combustion engine, most commonly automotive engines, by the means of a fuel injector. This article focuses on fuel injection in reciprocating piston and Wankel rotary engines.
All co ...
, using one injector. The fuel injection was a batch fire system and used a two piece cast aluminum dual-plenum manifold. This engine was available in
Chevrolet S-10
The Chevrolet S-10 is a compact pickup truck produced by Chevrolet. It was the first domestically-built compact pickup of the big three American automakers. When it was first introduced as a "quarter-ton pickup" in 1981 for the 1982 model year, ...
/
GMC Sonoma
GMC may refer to:
Government India
* Gandhinagar Municipal Corporation, in Gujarat
* Gobichettipalayam Municipal Corporation, in Tamil Nadu
* Guntur Municipal Corporation, in Andhra Pradesh
* Guwahati Municipal Corporation, in Assam
* Gwalior ...
pickups,
Chevrolet S-10 Blazer/GMC S-15 Jimmy/
Oldsmobile Bravada SUVs, and
Chevrolet Astro
The Chevrolet Astro is a minivan that was manufactured and marketed by the Chevrolet division of American auto manufacturer General Motors from 1985 to 2005. Sold alongside the GMC Safari, the Astro was marketed in multiple configurations, incl ...
/
GMC Safari vans only. The L35 was rated at and of torque.
The cylinder block was redesigned for use with a
balance shaft
Balance shafts are used in piston engines to reduce vibration by cancelling out unbalanced dynamic forces. The counter balance shafts have eccentric weights and rotate in the opposite direction to each other, which generates a net vertical force ...
. Cylinder heads (10238181 casting) used with the L35 have intake ports with eyebrows that clear the fuel injectors. Timing cover flange area was thickened in 1995 when some of the balance shaft motors had a six-bolt timing cover; some engines had a crankshaft position sensor (in conjunction with a redesigned distributor containing a pickup assembly which functions as a camshaft position sensor) when
OBD-II was phased in.
Legend
* 1 –
Chevrolet Astro
The Chevrolet Astro is a minivan that was manufactured and marketed by the Chevrolet division of American auto manufacturer General Motors from 1985 to 2005. Sold alongside the GMC Safari, the Astro was marketed in multiple configurations, incl ...
vans,
GMC Safari vans (Note: standard on AWD, optional on 2WD models)
* 2 –
Chevrolet S-10 Blazer
The Chevrolet (S-10) Blazer and its badge engineered GMC (S-15) Jimmy counterpart are compact/mid-size SUVs manufactured and marketed by Chevrolet and GMC from the 1983 through 2005 model years, over two generations – until the early 1990s a ...
,
GMC Jimmy
The Chevrolet (S-10) Blazer and its badge engineered GMC (S-15) Jimmy counterpart are Compact car, compact/mid-size SUVs manufactured and marketed by Chevrolet and GMC (automobile), GMC from the 1983 through 2005 model years, over two generation ...
,
Oldsmobile Bravada (Note: Oldsmobile Bravada not produced in 1995)
* 3 –
Chevrolet S-10
The Chevrolet S-10 is a compact pickup truck produced by Chevrolet. It was the first domestically-built compact pickup of the big three American automakers. When it was first introduced as a "quarter-ton pickup" in 1981 for the 1982 model year, ...
,
GMC Sonoma
GMC may refer to:
Government India
* Gandhinagar Municipal Corporation, in Gujarat
* Gobichettipalayam Municipal Corporation, in Tamil Nadu
* Guntur Municipal Corporation, in Andhra Pradesh
* Guwahati Municipal Corporation, in Assam
* Gwalior ...
(engine standard equipment with the S10 SS and Sonoma GT)
L35 and LF6 SCPI and MPFI
Major design changes were made to the V6 for the 1996 model year. Like other small block Chevrolet V8s, the engine received redesigned heads which had improved airflow and
combustion efficiency
Combustion efficiency refers to the effectiveness of the burning process in converting fuel into heat energy. It is measured by the proportion of fuel that is efficiently burned and converted into useful heat, while minimizing the emissions of po ...
. These heads are referred to as Vortec heads.
The engine block was revised with structural reinforcing ribs up front eliminating the two freeze plugs (on the front and back) along with an alloy oil pan (for the S-10, Blazer, and Jimmy). The 1996+ cast aluminum oil pan has 12 bolts where a 16-bolt oil pan from the earlier 4.3 does not interchange. These (1996–2000) engines came with a redesigned 4L60-E transmission with a removable bellhousing which bolts to the oil pan.
Crankshafts manufactured for the 1999 model year (to the end of production) had a pilot hole depth of when coupled to the LSx-based 4L60E, which had a redesigned torque converter pilot hub (which was longer and was used with a stator shaft). The torque converter pilot hub was longer than the early
4L60E (similar in appearance to the 1993–1995 700R4) or the second generation variants (incorporating a removable bellhousing) with the GMT330 or 1996–1998 C/K series.
This engine came in two versions, the LF6 rated at , and the L35 rated at . Only the S-series pick-ups used the LF6, while the full-size trucks, vans and Blazer and Jimmy used the L35 version. The L35 was optional on the S-Series trucks.
Legend
* 1 –
Chevrolet/GMC C/K trucks
* 2 –
Chevrolet Express/GMC Savana vans
* 3 –
Chevrolet Astro/GMC Safari vans
* 4 –
Chevrolet Blazer/GMC Jimmy, 1996–2001
Oldsmobile Bravada SUVs
* 5 –
Chevrolet S-10/GMC Sonoma trucks (2WD)
* 6 –
Chevrolet S-10/GMC Sonoma trucks (4WD)
* 7 –
Chevrolet Silverado/GMC Sierra trucks
LU3 and LG3 MPFI
2002 (2003 Year Model, Vin Code X for LU3, Vin Code W for L35) saw major changes to the fuel-injection system. For 2002, the
Chevrolet Astro
The Chevrolet Astro is a minivan that was manufactured and marketed by the Chevrolet division of American auto manufacturer General Motors from 1985 to 2005. Sold alongside the GMC Safari, the Astro was marketed in multiple configurations, incl ...
,
GMC Safari,
Chevrolet Silverado
The Chevrolet Silverado is a range of trucks manufactured by General Motors under the Chevrolet brand. Introduced for the 1999 model year, the Silverado is the successor to the long-running Chevrolet C/K model line. Taking its name from the to ...
, and
GMC Sierra
The Chevrolet Silverado is a range of trucks manufactured by General Motors under the Chevrolet brand. Introduced for the 1999 model year, the Silverado is the successor to the long-running Chevrolet C/K model line. Taking its name from the t ...
all came equipped with the updated LU3 in California emissions states. 2003 saw the L35 discontinued and the LU3 replacing it in all other applications. A new variation was also introduced in 2003, the LG3. From 2004 to 2014, the LU3 was the only produced.
The biggest change to the LU3 and LG3 was the fuel-injection system. These engines used a multipoint fuel-injection system, with six Multec II fuel injectors mounted at each intake port on the manifold. GM recommends the Multec II spider assembly (which is also available for the L30 and L31 small block V8 motors) as a replacement for the 1996–2002 SCPI injector/spider assembly since the poppet valves have been known to stick open. The sticking
poppet valve
A poppet valve (also sometimes called mushroom valve) is a valve typically used to control the timing and quantity of petrol (gas) or vapour flow into or out of an engine, but with many other applications.
It consists of a hole or open-ended ch ...
s have been attributed to
ethanol fuel
Ethanol fuel is fuel containing ethyl alcohol, the same type of alcohol as found in alcoholic beverages. It is most often used as a motor fuel, mainly as a biofuel additive for gasoline.
Several common ethanol fuel mixtures are in use aro ...
blends sold in the State of California. The composite upper
intake manifold
An inlet manifold or intake manifold (in American English) is the part of an internal combustion engine that supplies the fuel/air mixture to the cylinder (engine), cylinders. The word ''manifold (engineering), manifold'' comes from the Old Eng ...
and cast aluminum lower intake from the L35 engine is also used on the LU3. The LG3 uses a cast aluminum upper intake and a cast iron lower intake.
[ ] The lower intake eliminated the EGR valve.
The LU3 also received a "quiet cam" to help reduce vibration at both idle and high engine speeds. This camshaft used the same lift and duration as the older design, but the cam was reprofiled to keep the valve lifters in full contact with the cam lobes as the cam ramps down.
The LG3 was used in Chevrolet S-10 and GMC Sonoma pickups and was only produced for 2003. The LU3 was used in the Chevrolet and GMC full-size trucks and vans, the Chevrolet Astro and GMC Safari vans, and the Chevrolet S-10 Blazer and GMC S-15 Jimmy. The LG3 was rated at and of torque. The LU3 was rated at and of torque.
For the 2007–2013 GMT900 Silverado/Sierra 1500 trucks and 2008–2014 Express/Savana 1500 vans, the LU3 engine received a
Distributorless Ignition System: the traditional distributor was eliminated where a stub shaft was used. In addition, the crankshaft sensor was upgraded to a 58x reluctor wheel (same as the GEN IV LSx) which resulted in the timing cover redesigned (this time, the cover is aluminum alloy in lieu of the composite cover); the timing cover bolt pattern is not the same as the 1996–06 LU3 and L35.
Legend
* 1 –
Chevrolet Silverado
The Chevrolet Silverado is a range of trucks manufactured by General Motors under the Chevrolet brand. Introduced for the 1999 model year, the Silverado is the successor to the long-running Chevrolet C/K model line. Taking its name from the to ...
and
GMC Sierra
The Chevrolet Silverado is a range of trucks manufactured by General Motors under the Chevrolet brand. Introduced for the 1999 model year, the Silverado is the successor to the long-running Chevrolet C/K model line. Taking its name from the t ...
1500 trucks
* 2 –
Chevrolet Express
The Chevrolet Express (also known as the GMC Savana) is a series of full-size vans produced by General Motors since 1996. The successor to the Chevrolet G-series van, the Express is produced in passenger and cargo variants. Alongside the stan ...
and
GMC Savana
Savana is a town and commune in Madagascar. It belongs to the district of Vohipeno, which is a part of Vatovavy-Fitovinany Region. The population of the commune was estimated to be approximately 4,000 in the 2001 commune census.
Only primary s ...
vans
* 3 –
Chevrolet Astro
The Chevrolet Astro is a minivan that was manufactured and marketed by the Chevrolet division of American auto manufacturer General Motors from 1985 to 2005. Sold alongside the GMC Safari, the Astro was marketed in multiple configurations, incl ...
and
GMC Safari vans
* 4 –
Chevrolet Blazer
The Chevrolet Blazer is an automobile nameplate used by General Motors for its Chevrolet brand since 1969 for several SUV models:
* Full-size Chevrolet K5 Blazer, based on the C/K pickup chassis and built from 1969 to 1995 (renamed Blazer in 1992 ...
and
GMC Jimmy
The Chevrolet (S-10) Blazer and its badge engineered GMC (S-15) Jimmy counterpart are Compact car, compact/mid-size SUVs manufactured and marketed by Chevrolet and GMC (automobile), GMC from the 1983 through 2005 model years, over two generation ...
SUVs
* 5 –
Chevrolet S-10
The Chevrolet S-10 is a compact pickup truck produced by Chevrolet. It was the first domestically-built compact pickup of the big three American automakers. When it was first introduced as a "quarter-ton pickup" in 1981 for the 1982 model year, ...
and
GMC Sonoma
GMC may refer to:
Government India
* Gandhinagar Municipal Corporation, in Gujarat
* Gobichettipalayam Municipal Corporation, in Tamil Nadu
* Guntur Municipal Corporation, in Andhra Pradesh
* Guwahati Municipal Corporation, in Assam
* Gwalior ...
trucks (2WD)
* 6 –
Chevrolet S-10
The Chevrolet S-10 is a compact pickup truck produced by Chevrolet. It was the first domestically-built compact pickup of the big three American automakers. When it was first introduced as a "quarter-ton pickup" in 1981 for the 1982 model year, ...
and
GMC Sonoma
GMC may refer to:
Government India
* Gandhinagar Municipal Corporation, in Gujarat
* Gobichettipalayam Municipal Corporation, in Tamil Nadu
* Guntur Municipal Corporation, in Andhra Pradesh
* Guwahati Municipal Corporation, in Assam
* Gwalior ...
trucks (4WD)
Turbocharged LB4 4.3L V6
In 1991, GMC introduced the
GMC Syclone limited-edition truck that used a turbocharged V6. This engine used a
Mitsubishi
The is a group of autonomous Japanese multinational companies in a variety of industries.
Founded by Yatarō Iwasaki in 1870, the Mitsubishi Group traces its origins to the Mitsubishi zaibatsu, a unified company that existed from 1870 to 194 ...
TD06-17C
turbocharger
In an internal combustion engine, a turbocharger (also known as a turbo or a turbosupercharger) is a forced induction device that is powered by the flow of exhaust gases. It uses this energy to compress the intake air, forcing more air into th ...
,
Garrett
Garrett may refer to:
Places in the United States
* Garrett, Illinois, a village
* Garrett, Indiana, a city
* Garrett, Floyd County, Kentucky, an unincorporated community
* Garrett, Meade County, Kentucky, an unincorporated community
* Garrett, ...
water/air
intercooler
An intercooler is a heat exchanger used to cool a gas after compression. Often found in turbocharged engines, intercoolers are also used in air compressors, air conditioners, refrigeration and gas turbines.
Internal combustion engines
Mo ...
, and electronic multi-point fuel injection. Although GM made these modifications to the engine, it was still referred to with the RPO LB4 code. The majority of the
naturally aspirated
A naturally aspirated engine, also known as a normally aspirated engine, and abbreviated to N/A or NA, is an internal combustion engine in which air intake depends solely on atmospheric pressure and does not have forced induction through a turboc ...
LB4's long-block was shared with the turbo version. However, the vehicles that used the turbo engine also included RPO code ZR9. Internal engine upgrades included nodular iron main bearing caps, graphite composite head gaskets with
stainless steel
Stainless steel, also known as inox, corrosion-resistant steel (CRES), or rustless steel, is an iron-based alloy that contains chromium, making it resistant to rust and corrosion. Stainless steel's resistance to corrosion comes from its chromi ...
flanges, and
hypereutectic piston
A hypereutectic piston is an internal combustion engine piston cast using a hypereutectic aluminum alloy with silicon content greater than the eutectic point of 12 weight percent silicon. Most aluminum-silicon casting alloys are hypoeutectic, me ...
s which lowered the engine compression to 8.35:1.
A unique intake manifold that used the twin-bore throttle body from the 5.7L TPI Corvette engine was used on the engine's top end.
The turbocharged was last used in the
GMC Typhoon
The GMC Typhoon is a high-performance Sport utility vehicle, SUV, produced from 1992 until 1993 by GMC (marque), GMC. The Typhoon was based on the 1991 GMC Syclone.
Description
Like the GMC Syclone, the Typhoon is powered by a 4.3 L LB4 V6 engine ...
in the 1993 model year. The engine produced at 4400 rpm and of torque at 3600 rpm.
Marine Applications
Mercury Marine
Mercury Marine is a marine engine division of Brunswick Corporation headquartered in Fond du Lac, Wisconsin. The main product line is outboard motors. It also produces the MerCruiser line of sterndrives and inboard engines, as well as a li ...
, which sells its engines under the Mercruiser brand, developed the 4.5L V6 Mercruiser engine, producing 200 HP or 250 HP. It was based on the architecture using similar dimensions, except that it has a stroke length of 3.6 inches.
Generation V
4.3L (262 CID)
Commencing with the 2014 model year, a new LV3 EcoTec3 4300, based on GM's GEN V (LT1) small-block V8, became the new base engine for the next-generation Chevrolet Silverado/GMC Sierra 1500 full-size trucks, and since 2018, it has become the new base engine for the Chevrolet Express/GMC Savana full-size vans. This aluminum block and head design was significantly different from the cast iron engine it replaced, signaling an end to a design dating back to 1955. Like its small-block V8 counterparts, GM Powertrain has also sold the engine for marine and industrial applications. This engine is manufactured in Tonowanda NY and Ramos Mexico.
LV3
The LV3 V6 is an all-new engine announced by GM at the end of 2012. GM considers this a new engine design which inherits from its predecessors its displacement, 2-valve
pushrod
A valvetrain is a mechanical system that controls the operation of the intake and exhaust valves in an internal combustion engine. The intake valves control the flow of air/fuel mixture (or air alone for direct-injected engines) into the combu ...
valvetrain
A valvetrain is a mechanical system that controls the operation of the intake and exhaust valves in an internal combustion engine. The intake valves control the flow of air/fuel mixture (or air alone for direct-injected engines) into the combu ...
, 90-degree cylinder angle, and bore centers. It is based on the fifth-generation
LT engine and includes the same features such as
direct injection, piston cooling jets,
active fuel management
Active Fuel Management (formerly known as displacement on demand (DoD)) is a trademarked name for the automobile variable displacement technology from General Motors. It allows a V6 or V8 engine to "turn off" half of the cylinders under light-l ...
,
variable displacement
Variable displacement is an automobile engine technology that allows the engine displacement to change, usually by deactivating cylinders, for improved fuel economy. The technology is primarily used in large multi-cylinder engines. Many automobile ...
oil pump,
continuously variable valve timing
Variable valve timing (VVT) is the process of altering the timing of a valve lift event in an internal combustion engine, and is often used to improve performance, fuel economy or emissions. It is increasingly being used in combination with vari ...
, and aluminum
cylinder head
In a piston engine, the cylinder head sits above the cylinders, forming the roof of the combustion chamber. In sidevalve engines the head is a simple plate of metal containing the spark plugs and possibly heat dissipation fins. In more modern ...
s and
block
Block or blocked may refer to:
Arts, entertainment and media Broadcasting
* Block programming, the result of a programming strategy in broadcasting
* W242BX, a radio station licensed to Greenville, South Carolina, United States known as ''96.3 ...
. The engine is
SAE certified to at 5300
rpm
Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or r⋅min−1) is a unit of rotational speed (or rotational frequency) for rotating machines.
One revolution per minute is equivalent to hertz.
Standards
ISO 80000-3:2019 def ...
and at 3900 rpm on regular unleaded
gasoline
Gasoline ( North American English) or petrol ( Commonwealth English) is a petrochemical product characterized as a transparent, yellowish, and flammable liquid normally used as a fuel for spark-ignited internal combustion engines. When for ...
and at 5300 rpm and at 3900 rpm on
E85. Emissions are controlled by a
close-coupled catalytic converter, Quick Sync 58X ignition, returnless fuel rail, and fast-response O
2 sensor.
It was launched in the all-new 2014
Chevrolet Silverado
The Chevrolet Silverado is a range of trucks manufactured by General Motors under the Chevrolet brand. Introduced for the 1999 model year, the Silverado is the successor to the long-running Chevrolet C/K model line. Taking its name from the to ...
and
GMC Sierra
The Chevrolet Silverado is a range of trucks manufactured by General Motors under the Chevrolet brand. Introduced for the 1999 model year, the Silverado is the successor to the long-running Chevrolet C/K model line. Taking its name from the t ...
1500.
Trio of New EcoTec3 Engines Powers Silverado and Sierra
/ref> 2021 was its final model year in the Chevrolet Silverado and GMC Sierra 1500, as the 6-speed automatic transmission was phased out. The Chevrolet Express and GMC Savana are the last vehicles to use the 4.3L but do not feature Active Fuel Management and their version of the engine is referred to as the LV1.
Applications:
* 2014–2021 Chevrolet Silverado
The Chevrolet Silverado is a range of trucks manufactured by General Motors under the Chevrolet brand. Introduced for the 1999 model year, the Silverado is the successor to the long-running Chevrolet C/K model line. Taking its name from the to ...
1500
* 2014–2021 GMC Sierra
The Chevrolet Silverado is a range of trucks manufactured by General Motors under the Chevrolet brand. Introduced for the 1999 model year, the Silverado is the successor to the long-running Chevrolet C/K model line. Taking its name from the t ...
1500
LV1
The LV1 engine is essentially the same as the LV3, but without Active Fuel Management technology. The LV1 made its debut in the 2018 model year GM full-size vans—the 2018 Chevrolet Express
The Chevrolet Express (also known as the GMC Savana) is a series of full-size vans produced by General Motors since 1996. The successor to the Chevrolet G-series van, the Express is produced in passenger and cargo variants. Alongside the stan ...
and GMC Savana—as the successor to the 4.8L Vortec engine.
See also
* Chevrolet small-block engine (first- and second-generation)
The Chevrolet small-block engine is a series of Gasoline engine, gasoline-powered V8 engine, V8 automobile internal combustion engine, engines, produced by the Chevrolet division of General Motors in two overlapping generations between 1954 and ...
* General Motors LS-based small-block engine
The General Motors LS-based small-block engines are a family of V8 and offshoot V6 engines designed and manufactured by the American automotive company General Motors. Introduced in 1997, the family is a continuation of the earlier first- ...
* GM High Value engine
The High Value engine family from General Motors is a group of cam-in-block or overhead valve V6 engines. These engines feature cast iron blocks and aluminum heads, and use the same 60° vee bank as the 60° V6 family they are based on, but the n ...
, 3.5L and 3.9L V6s
* GM High Feature engine
The GM High Feature engine (also known as the HFV6, and including the 3600 LY7 and derivative LP1) is a family of modern DOHC V6 engines produced by General Motors. The series was introduced in 2004 with the Cadillac CTS and the Holden Commodore ...
Notes
References
*
*
*
{{DEFAULTSORT:General Motors 90 V6 engine
90-Degree V6 engine
V6 engines
Gasoline engines by model