The LA engines are a family of
pushrod
A valvetrain or valve train 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) ...
OHV small block 90°
V-configured gasoline engine
A petrol engine (gasoline engine in American English) is an internal combustion engine designed to run on petrol (gasoline). Petrol engines can often be adapted to also run on fuels such as liquefied petroleum gas and ethanol blends (such as '' ...
s built by
Chrysler Corporation. It was factory-installed in passenger vehicles, trucks and vans, commercial vehicles, marine and industrial applications from 1964 through 1991 (318) & 1992 (360). The
combustion chamber
A combustion chamber is part of an internal combustion engine in which the fuel/air mix is burned. For steam engines, the term has also been used for an extension of the firebox which is used to allow a more complete combustion process.
Intern ...
s are
wedge-shaped, rather than the
polyspherical combustion chambers in the predecessor ''
A engine'' or the
hemispherical combustion chambers in the
Chrysler Hemi engine. LA engines have the same bore spacing as the A engines. LA engines were made at Chrysler's
Mound Road Engine plant in
Detroit
Detroit ( , ; , ) is the largest city in the U.S. state of Michigan. It is also the largest U.S. city on the United States–Canada border, and the seat of government of Wayne County. The City of Detroit had a population of 639,111 at ...
,
Michigan
Michigan () is a U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest, upper Midwestern United States. With a population of nearly 10.12 million and an area of nearly , Michigan is the List of U.S. states and ...
, as well as plants in Canada and Mexico. The "LA" stands for "Light A", as the 1956 - 1967 "A" engine it was closely based on and shares many parts with was nearly 50 pounds heavier.
The "LA" and "A" production overlapped from 1964 - 1966 in the US and through 1967 in export vehicles when the "A" 318 engine was phased out.
Willem Weertman, who later became Chief Engineer – Engine Design and Development, was in charge of the conversion.
The basic design of the LA engine would go unchanged through the development of the "Magnum" upgrade (1992-1993) and into the 2000s with changes to enhance power and efficiency.
239 V6
The
V6 was released in 1987 for use in the
Dodge Dakota
The Dodge Dakota, known as the Ram Dakota for the final two years of production, is a mid-size pickup truck from Chrysler's Ram (formerly Dodge Truck) division. The first Dakota was introduced in late 1986 as a 1987 model. From its introduction th ...
and as a replacement for the older, longer
Slant-Six for the Dodge RAM. It is essentially a six-cylinder version of the
318
Year 318 ( CCCXVIII) was a common year starting on Wednesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Licinianus and Crispus (or, less frequently, year 1071 ''Ab ur ...
V8. The bore and stroke are 99.3 mm (3.9 in) and 84 mm (3.3 in), respectively. Output was and until it was replaced by the
Magnum 3.9 starting in 1992. In 1987 it used a two-barrel
Holley carburetor
A carburetor (also spelled carburettor) is a device used by an 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 venturi tube in the main meter ...
and hydraulic
tappet
A tappet is most commonly a component in an internal combustion engine which converts the rotating motion of the camshaft into linear motion of the valves, either directly or indirectly.
An earlier use of the term was for part of the valve gear ...
s. In 1988 it was upgraded with
throttle-body fuel injection
Manifold injection is a mixture formation system for internal combustion engines with external mixture formation. It is commonly used in engines with spark ignition that use petrol as fuel, such as the Otto engine, and the Wankel engine. In a ma ...
and roller tappets which it retained until the 1992 Magnum update. Next, in the 1992 Magnum update, the throttle-body fuel injection was upgraded to a multi-port fuel injection. In 1997, it was then upgraded to
sequential fuel injection. The engine was produced through 2004 before it was replaced with the 3.7 L Power Tech V6.
* 1987–1991
Dodge Dakota
The Dodge Dakota, known as the Ram Dakota for the final two years of production, is a mid-size pickup truck from Chrysler's Ram (formerly Dodge Truck) division. The first Dakota was introduced in late 1986 as a 1987 model. From its introduction th ...
* 1992–2004
Dodge Dakota
The Dodge Dakota, known as the Ram Dakota for the final two years of production, is a mid-size pickup truck from Chrysler's Ram (formerly Dodge Truck) division. The first Dakota was introduced in late 1986 as a 1987 model. From its introduction th ...
Magnum
* 1988–1991
Dodge Ram
The Ram pickup (marketed as the Dodge Ram until 2010) is a full-size pickup truck manufactured by Chrysler, Stellantis North America (formerly Chrysler Group LLC and FCA US LLC) and marketed from 2010 onwards under the Ram Trucks brand. The cur ...
* 1992–2001
Dodge Ram
The Ram pickup (marketed as the Dodge Ram until 2010) is a full-size pickup truck manufactured by Chrysler, Stellantis North America (formerly Chrysler Group LLC and FCA US LLC) and marketed from 2010 onwards under the Ram Trucks brand. The cur ...
Magnum
* 1988–1991
Dodge Ram Van
* 1992–2003
Dodge Ram Van Magnum
273 V8
The was the first LA engine, beginning model year 1964 and offered through 1969, rated at . It had a bore and stroke of . It had a mechanical solid lifter valvetrain until 1968 when hydraulic lifters were introduced; hydraulic lifters generally make for a quieter valvetrain. The reciprocating assembly included a cast or forged steel crankshaft, drop forged steel connecting rods and cast aluminum pistons. The valvetrain consisted of a cast nodular iron camshaft, solid or hydraulic lifters, solid pushrods and shaft-mounted, malleable iron rocker arms (stamped steel on later hydraulic-cam engines). These actuated the overhead steel intake and exhaust valves. The cylinder heads featured wedge-shaped combustion chambers with a single intake and a single exhaust valve for each cylinder. Spark plugs were located in the side of the cylinder head, between the exhaust ports.
A high performance was offered 1965-'67, this was standard in the
Barracuda Formula S model and optional in all other compact models excluding station wagons. It featured a 4-bbl. carburetor and matching intake manifold, chrome unsilenced air cleaner with callout sticker, longer-duration and higher-lift camshaft and stronger valve springs, 10.5:1 compression ratio, special black wrinkle valve covers with extruded aluminum appliques, and a low-restriction exhaust system with a exhaust pipe, collector-type Y-junction, and exposed resonator. In 1965 (only) the muffler was of "straight through" construction.
A special version was also available in 1966 only - it used a lift solid-lifter camshaft, fabricated-steel-tube exhaust, and a Holley 4-barrel carburetor, producing (1 hp/cu in). It was available in the
Dodge Dart
Dodge Dart is a line of automobiles marketed by Dodge from the 1959 to 1976 model years in North America, with production extended to later years in various other markets.
The Dart name originally appeared on a 1956 Chrysler show car featurin ...
only, and the car so equipped was called the "D-Dart", a reference to its classification in NHRA D-stock for drag racing, which was the car's only intended purpose.
* 1964–1969
Dodge Dart
Dodge Dart is a line of automobiles marketed by Dodge from the 1959 to 1976 model years in North America, with production extended to later years in various other markets.
The Dart name originally appeared on a 1956 Chrysler show car featurin ...
* 1964–1969
Plymouth Barracuda
*
Plymouth Belvedere
*
Dodge Coronet
The Dodge Coronet is an automobile that was marketed by Dodge in seven generations, and shared nameplates with the same bodyshell with varying levels of equipment installed. Introduced as a full-size car in 1949, it was the division's highest tr ...
*
Plymouth Satellite
* 1964–1969
Plymouth Valiant
The Plymouth Valiant (first appearing in 1959 as simply the Valiant) is an automobile which was marketed by the Plymouth division of the Chrysler Corporation in the United States from the model years of 1960 through 1976. It was created to give ...
* 1966–1967
Ghia 450 SS
318 V8
Like all LA engines, the LA 318 was a relative of the
A 318. Like the A 318, it has a bore & stroke of X . It appeared in volume production beginning with the 1968 model year, replacing the last of the export "A" 318 engines equipped with polyspherical chambered heads ("A" 318 engines were not offered in 1967 domestic vehicles). The LA engine was available until 1991 when it was superseded by the Magnum version (See below). It used hydraulic lifters and a two barrel carburetor for most of its production, though four-barrel
Carter Thermo-Quad and
Rochester
Rochester may refer to:
Places Australia
* Rochester, Victoria
Canada
* Rochester, Alberta
United Kingdom
*Rochester, Kent
** City of Rochester-upon-Medway (1982–1998), district council area
** History of Rochester, Kent
** HM Prison ...
Quadrajet carburetors were used in police applications starting in 1978 and 1985, respectively. The 318 2bbl ELD received roller lifters and a fast-burn chambered cylinder head in 1985 (The Police ELE 318 4bbl continued to use modified J heads and hydraulic flat tappets through 1989).
Throttle-body electronic fuel injection was factory equipment on the 1981-1983
Imperial
Imperial is that which relates to an empire, emperor, or imperialism.
Imperial or The Imperial may also refer to:
Places
United States
* Imperial, California
* Imperial, Missouri
* Imperial, Nebraska
* Imperial, Pennsylvania
* Imperial, Texas
...
. From 1988 to 1991, another throttle-body fuel injection system was used for truck and van applications.
* 1983–1989
Chrysler Fifth Avenue
* 1981–1983
Chrysler Imperial (fuel injection)
* 1968–1981
Chrysler Valiant
* 1977–1981
Chrysler LeBaron
* 1979-1982
Chrysler New Yorker
* 1981–1983
Chrysler Imperial
* 1975–1983
Chrysler Cordoba
* 1976–1980
Dodge Aspen
*
Dodge Charger
*
Dodge Challenger
*
Dodge Coronet
The Dodge Coronet is an automobile that was marketed by Dodge in seven generations, and shared nameplates with the same bodyshell with varying levels of equipment installed. Introduced as a full-size car in 1949, it was the division's highest tr ...
* 1968–1976
Dodge Dart
Dodge Dart is a line of automobiles marketed by Dodge from the 1959 to 1976 model years in North America, with production extended to later years in various other markets.
The Dart name originally appeared on a 1956 Chrysler show car featurin ...
* 1977–1989
Dodge Diplomat
* 1991-1992
Dodge Dakota
The Dodge Dakota, known as the Ram Dakota for the final two years of production, is a mid-size pickup truck from Chrysler's Ram (formerly Dodge Truck) division. The first Dakota was introduced in late 1986 as a 1987 model. From its introduction th ...
* 1971–1972
Dodge Demon Dodge Demon may refer to
* Dodge Dart Demon, a 2-door fastback coupe variant of the 1971–1972 Dodge Dart
* Dodge Demon (concept car), first shown in 2007
* Dodge Challenger SRT Demon, a highly modified variant of the 2018 Dodge Challenger
{{ ...
* 1973–1976
Dodge Dart Sport
*1970-1980 (Valiant)
Dodge Super Bee
The Dodge Super Bee is a mid-sized muscle car marketed by Dodge, that was produced for the 1968 through 1971 model years.
In Mexico, the Super Bee was based on a compact-sized Chrysler platform and marketed from 1970 until 1980.
The Super Bee ...
(Mexico)
* 1971–1979
Dodge GTX
The Dodge GTX is a muscle car manufactured by Chrysler-Fevre Argentina S.A. under the Dodge brand. It was a development made on the basis of the 1960/66 platform A (Early A-Body), consisting of a coupe without studs (hardtop) with a sporty cut, mu ...
(Argentina)
* 1978-1979
Dodge Magnum
* 1980–1983
Dodge Mirada
* 1967–1992
Dodge Ram
The Ram pickup (marketed as the Dodge Ram until 2010) is a full-size pickup truck manufactured by Chrysler, Stellantis North America (formerly Chrysler Group LLC and FCA US LLC) and marketed from 2010 onwards under the Ram Trucks brand. The cur ...
*
Dodge Ram Van
* 1974-1992
Dodge Ramcharger
The Dodge Ramcharger is a large sport utility vehicle built by Dodge from 1974 to 1993, based on a shortened-wheelbase version of the Dodge D Series/ Ram pickup truck chassis. A Plymouth version, named the Plymouth Trail Duster, offered from 1974 ...
* 1968–1974
Plymouth Barracuda
*
Plymouth Belvedere
* 1970–1976
Plymouth Duster
* 1967-1972
Plymouth Fury
* 1972–1989
Plymouth Gran Fury
* 1964-1974
Plymouth Satellite
* 1974-1981
Plymouth Trail Duster
Plymouth () is a port city and unitary authority in South West England. It is located on the south coast of Devon, approximately south-west of Exeter and south-west of London. It is bordered by Cornwall to the west and south-west.
Plymouth' ...
* 1968–1976
Plymouth Valiant
The Plymouth Valiant (first appearing in 1959 as simply the Valiant) is an automobile which was marketed by the Plymouth division of the Chrysler Corporation in the United States from the model years of 1960 through 1976. It was created to give ...
* 1976–1980
Plymouth Volaré
* 1981-19??
Allard J2X2
* 1976-1979
Monteverdi Safari
The Monteverdi Safari is a Swiss luxury SUV first presented by Peter Monteverdi in 1976. It entered into production in 1977. Production came to an end in 1982, after production of the International Harvester Scout (upon which the Safari was based, ...
* 1977-1980
Monteverdi Sierra
* Volkswagen 11-160/22-160 (Ethanol-powered VW Truck)
* Dodge E-13 (Ethanol-powered Truck)
* Companhia Brasileira de Tratores (CBT) 3000 and 3500 (Ethanol powered tractor)
340 V8

In the mid-1960s, Chrysler decided to adapt the small block V8 into a lightweight, high output engine equally suited for drag strip or street performance use. Its block was bored out to but stroke left unchanged, resulting in the engine introduced for the 1968 model year. Anticipating higher loads resulting from racing operation, the engineers fitted a forged
shot peened steel crankshaft instead of the
cast nodular iron unit used in the 318. This also included shot peened hammer-forged steel connecting rods and high compression cast aluminum pistons with full floating pins. A 4-barrel carburetor was mated to a high-rise, dual plane intake manifold feeding high-flow cylinder heads Its big ports used intake and exhaust valves. An aggressive cam was fitted to take advantage of the much better breathing top end. The 1968 4-speed cars got an even hotter cam, but it was discontinued for 1969, where both automatic and manual cars shared the same cam. The engine was equipped with hydraulic lifters and two bolt main bearing caps, leading some to initially underestimate the 340's potential. The 1968-'71 340's compression ratio was 10.5:1, placing it near the limit of what was possible on pump gasoline during that era. The 340 also used additional heavy-duty parts, such as a double-row roller timing chain and sump-mounted windage tray. Power output was officially stated as gross for the 4 barrel.
In 1970, Chrysler offered a special Six-Pack version of the 340 with triple 2-barrel carburetors rated at
gross that was specific to
Challenger TA and
Cuda AAR models. This version featured a heavy duty short block with additional webbing to allow for aftermarket installed 4 bolt main bearing caps. The application-specific cylinder heads featured relocated intake pushrod passages with offset rocker arms that allowed the pushrods to be moved away from the intake ports, which could improve airflow if the pushrod-clearance "hump" was ground away from the intake port by the end user. An aluminum intake manifold mounted three Holley carburetors, and a dual points ignition system was fitted.
The combination of rising gasoline prices and insurance company crackdown on high-performance vehicles saw the relatively expensive 340 detuned and phased out. It remained a high performance engine through 1971, but was de-tuned in 1972 with the introduction of low compression (8.5:1) small valve heads, and by mid-year, a cast nodular iron crankshaft, and a variety of other emissions related changes. For the 1974 model year it was replaced by the engine.
* Chrysler
Valiant Charger (Australia)
*
Dodge Challenger
*
Dodge Charger
*
Dodge Dart
Dodge Dart is a line of automobiles marketed by Dodge from the 1959 to 1976 model years in North America, with production extended to later years in various other markets.
The Dart name originally appeared on a 1956 Chrysler show car featurin ...
* 1971–1972
Dodge Demon Dodge Demon may refer to
* Dodge Dart Demon, a 2-door fastback coupe variant of the 1971–1972 Dodge Dart
* Dodge Demon (concept car), first shown in 2007
* Dodge Challenger SRT Demon, a highly modified variant of the 2018 Dodge Challenger
{{ ...
*
Dodge Super Bee
The Dodge Super Bee is a mid-sized muscle car marketed by Dodge, that was produced for the 1968 through 1971 model years.
In Mexico, the Super Bee was based on a compact-sized Chrysler platform and marketed from 1970 until 1980.
The Super Bee ...
*
Plymouth Barracuda
*
Plymouth Duster
*
Plymouth Road Runner
The Plymouth Road Runner is a mid-size car with a focus on performance built by Plymouth in the United States between 1968 and 1980. By 1968, some of the original muscle cars were moving away from their roots as relatively cheap, fast cars as ...
*
Plymouth Sport Fury GT
*
Monica 560
*
Hongqi CA770 215 HP
360 V8

The LA has a bore and stroke of . It was released in 1971 with a two barrel
carburetor
A carburetor (also spelled carburettor) is a device used by an 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 venturi tube in the main meter ...
. The 360 used the large intake port 340 heads with a smaller intake valve of . In 1974, with the introduction of the code E58 4-BBl dual exhaust version, at
SAE net, became the most powerful LA engine with the end of 340 production. Power started dropping from 1975 on as more emission controls were added resulting with the 1980 E58 engine only producing SAE net. Starting with 1981, the 360 was exclusively used in Dodge trucks and
vans
Vans is an American manufacturer of skateboarding shoes and related apparel, established in Anaheim, California, and owned by VF Corporation. The company also sponsors surf, snowboarding, BMX, and motocross teams. From 1996 to 2019, the co ...
.
The 1978-1979 Li'l Red Express truck used a special high-performance 360 4-barrel engine with factory production code EH1 that was rated at 225 SAE Net HP in production form The EH1 was a modified version of the E58 360 police engine (E58) producing net at 3800 rpm due in part, that as it was installed in a "truck", and not a car, it did not have to use catalytic converters (1978 only) which allowed for a free-flowing exhaust system. Some prototypes for the EH1 featured Mopar Performance W2 heads, although the production units had the standard 360 heads. Some police package cars came from the factory with a steel crank and h-beam rods.
There was also a "lean burn" version of the 360. The LA360 was replaced in 1993 by the 5.9 Magnum, which shared some design parameters with the LA360, however the majority of its components were different.
Due to additional modifications, the prototype Li'l Red Express truck tested by various period magazines ran appreciably stronger than actual production examples.
*
Chrysler 300
*
Chrysler Valiant &
Valiant Charger (Australia)
*
Chrysler by Chrysler
The Chrysler by Chrysler is an automobile produced by Chrysler Australia from 1971 to 1976. It is an extended wheelbase, luxury variant of the Australian developed Chrysler Valiant.
CH Series
The original CH Series Chrysler was introduced in Nov ...
(Australia)
* 1975–1979
Chrysler Cordoba
* 1978–1979
Chrysler LeBaron
* 1977–1980
Chrysler New Yorker
* 1971–1980
Chrysler Newport
* 1976–1980
Dodge Aspen
* 1974
Dodge Challenger
* 1974–1978
Dodge Charger
* 1974–1976
Dodge Coronet
The Dodge Coronet is an automobile that was marketed by Dodge in seven generations, and shared nameplates with the same bodyshell with varying levels of equipment installed. Introduced as a full-size car in 1949, it was the division's highest tr ...
* 1974–1976
Dodge Dart
Dodge Dart is a line of automobiles marketed by Dodge from the 1959 to 1976 model years in North America, with production extended to later years in various other markets.
The Dart name originally appeared on a 1956 Chrysler show car featurin ...
* 1978–1979
Dodge Diplomat
* 1978–1979
Dodge Magnum
* 1971–1978
Dodge Monaco
* 1971–1973
Dodge Polara
* 1971–1980
Dodge D Series
* 1981–1992
Dodge Ram
The Ram pickup (marketed as the Dodge Ram until 2010) is a full-size pickup truck manufactured by Chrysler, Stellantis North America (formerly Chrysler Group LLC and FCA US LLC) and marketed from 2010 onwards under the Ram Trucks brand. The cur ...
* 1979–1992
Dodge Ram Van/
Dodge Ram Wagon
* 1971–1992
Dodge Sportsman/
Dodge Tradesman
* 1974–1992
Dodge Ramcharger
The Dodge Ramcharger is a large sport utility vehicle built by Dodge from 1974 to 1993, based on a shortened-wheelbase version of the Dodge D Series/ Ram pickup truck chassis. A Plymouth version, named the Plymouth Trail Duster, offered from 1974 ...
* 1974-1981
Plymouth Trail Duster
Plymouth () is a port city and unitary authority in South West England. It is located on the south coast of Devon, approximately south-west of Exeter and south-west of London. It is bordered by Cornwall to the west and south-west.
Plymouth' ...
* 1974-1975
Plymouth Road Runner
The Plymouth Road Runner is a mid-size car with a focus on performance built by Plymouth in the United States between 1968 and 1980. By 1968, some of the original muscle cars were moving away from their roots as relatively cheap, fast cars as ...
* 1974
Plymouth Barracuda
* 1974–1976
Plymouth Duster
* 1971–1978
Plymouth Fury
* 1975–1977, 1980
Plymouth Gran Fury
* 1974–1983
Plymouth Voyager
* 1979–1980
Dodge St. Regis
The Dodge St. Regis is an automobile that was marketed by Dodge from the 1979 to 1981 model years. Replacing the Monaco, the St. Regis was the largest Dodge sedan, slotted above the mid-size Diplomat and Aspen. In contrast to both the Monaco and ...
* 1976–1980
Plymouth Volare and Dodge B-series vans
* 1978–1979 Dodge Lil' Red Express
* (in Bristol-modified form)
**
Bristol 603
**
Bristol 412
The Bristol 412 is a car which was produced by British manufacturer Bristol Cars from 1975 to 1986. Variants were produced as the Bristol Beaufighter, from 1980 to 1993, and as the Bristol Beaufort, from 1984 to 1994.
Bristol 412
Along with th ...
* (in Bristol-modified form with
turbocharger
In an internal combustion engine, a turbocharger (often called a turbo) is a forced induction device that is powered by the flow of exhaust gases. It uses this energy to compress the intake gas, forcing more air into the engine in order to pr ...
)
**
Bristol Beaufighter
The Bristol Type 156 Beaufighter (often called the Beau) is a British Multirole combat aircraft, multi-role aircraft developed during the Second World War by the Bristol Aeroplane Company. It was originally conceived as a heavy fighter varian ...
**
Bristol Brigand
**
Bristol Beaufort
The Bristol Beaufort (manufacturer designation Type 152) is a British twin-engined torpedo bomber designed by the Bristol Aeroplane Company, and developed from experience gained designing and building the earlier Blenheim light bomber. At l ...
Interim solutions: the throttle body injected LA engines
The last variation of the LA series to be introduced before the Magnum upgrade was the 1988-92
throttle-body fuel injection
Manifold injection is a mixture formation system for internal combustion engines with external mixture formation. It is commonly used in engines with spark ignition that use petrol as fuel, such as the Otto engine, and the Wankel engine. In a ma ...
, roller cam engine. The first engines to receive these modifications were the V8 and V6 engines. A Holley/Chrysler-designed, single-point, twin-injector throttle body assembly that was mounted atop a slightly re-designed cast iron intake manifold. An in-tank electric pump and reservoir replaced the earlier mechanical (camshaft-
eccentric driven) pump. The valvetrain was upgraded to include hydraulic roller lifters, however cam specs remained essentially unchanged. The resulting engine was somewhat improved as to power and efficiency. The 5.9 L V8 engines followed suit in 1989, but also received the overall improved "308" cylinder heads (casting number 4448308) that featured significantly higher flowing exhaust ports and a return to the original 1971 (non fast burn) combustion chamber. However, with other manufacturers already introducing the superior multi-point fuel injection system, Chrysler Corporation considered a more drastic upgrade program.
As the TBI engines were being introduced, the new upgrade program was initiated in the Chrysler engineering department. In 1992, with emissions standards becoming ever more stringent in the United States, Chrysler Corporation released the first of the upgraded engines.
Magnum engines
In 1992, Chrysler introduced the first of a series of upgraded versions of the LA engines. The company named their engine the "Magnum", a marketing term that had been used by the company previously to describe both the
Dodge Magnum automobile and an earlier Dodge passenger car (only) engine series; the latter was based on the big-block B/RB V8 engines of the 1960s-70s.
The Chrysler Magnum engines are a series of V6, V8, and V10 powerplants used in a number of
Chrysler Corporation motor vehicles, as well as in marine and industrial applications. This family of gasoline-burning engines lasted for over a decade, were installed in vehicles sold across the globe, and were produced in the millions.
Technical information
The Magnum engine is a direct descendant of the Chrysler LA engine, which began with the V8 in 1964.
While the Magnum 3.9, Magnum 5.2, and Magnum 5.9 (1992-up) engines were significantly based on the 239, the 318, and the 360 — respectively — many of the parts will not directly interchange and the Magnums are not technically LA engines; the only major parts that are actually unchanged are the connecting rods.
The cylinder block remained basically the same. It was still a V-shaped, 90-degree design made of cast iron. The crankshaft, located to the bottom of the block by five main bearing caps, was cast nodular iron, and the eight connecting rods were forged steel. The pistons were cast aluminum, with a
hypereutectic design.
Cylinders were numbered from the front of the engine to the rear; cylinders 1, 3, 5 and 7 were found on the left (driver side) bank, or "bank 1", with the even numbers on the other bank.
Coolant passages were located between the cylinders. The gerotor-type oil pump was located at the bottom rear of the engine, and provided oil to both the crankshaft main bearings and the cylinder heads (via the lifters and pushrods, as opposed to a drilled passage on LA engines). Chrysler's engineers also redesigned the oil seals on the crankshaft to improve anti-leak seal performance.
[L. Shepard & M Gingerella, "Magnum Engines", Chrysler Corp., 2000, ISBN] The oil pan was also made from thicker steel, and was installed with a more leak-resistant silicone-rubber gasket.
Gasoline was supplied to the intake manifold through a pair of steel rails that fed eight Bosch-type, top-fed, electronically actuated fuel injectors; there was one injector located in each intake runner. Each cylinder had its own injector, thus making the fuel system a "multi-point" type. Fuel pressure was regulated by a vacuum-controlled pressure regulator, located on the return side of the second fuel rail. Excess fuel was thereafter delivered back to the fuel tank. (Later versions had the regulator and filter mounted at the in-tank pump).
To support the new fuel system, the intake manifold was of a new design. Known colloquially as the "beer keg" or "kegger" manifold, the part was shaped like half of a beer barrel lying longitudinally atop the center of the V-shaped engine block. The intake runners, which supplied the fuel and air to each cylinder, fed each of the intake ports in the newly designed cylinder heads. The bolts that secured the intake manifold to the cylinder heads were installed at a different angle from those on the older LA engine; they threaded in vertically, rather than at the 45-degree angle of the 1966-up LA.
Air was provided from the air filter intake to the intake manifold by a Holley-designed, aluminum, twin-venturi, mechanically actuated throttle body, which was bolted atop the intake manifold. Each venturi was progressively bored and had a diameter of 50mm.
To this unit were mounted the Throttle Position Sensor (TPS), Manifold Absolute Pressure (MAP) sensor and Idle Air Control (IAC) valve (initially referred to as the "AIS Motor"). A steel cable connected the accelerator pedal inside the vehicle to a mechanical linkage at the side of the throttle body, which acted to open the air intake butterfly valves inside the venturis. During idle these butterfly valves were closed, so a bypass port and the IAC valve were used to control the intake of air.
The cylinder heads were another fundamental change of the Magnum engine, being designed to meet stricter requirements in both power and emissions by increasing efficiency.
These heads were cast iron units with new wedge-shaped combustion chambers and high-swirl valve shrouding.
Combustion chamber design was most important in these new heads: LA engine cylinder heads were given a full-relief open-chamber design, but the Magnum was engineered with a double-quench closed-chamber type. The higher-flowing intake ports stepped up intake flow dramatically in comparison to the original LA heads, and the exhaust ports improved cylinder evacuation as well.
The shape and porting of the chambers allowed for more complete atomization of the air/fuel mixture, as well as contributing to more complete combustion; these virtues allowed for much greater efficiency of the engine as a whole.
The intake and exhaust valves were located at the top of each combustion chamber. The valves themselves had shorter, 5/16" diameter stems, to allow for the more aggressive camshaft.
Intake valves had a port diameter of 1.92", while exhaust valves were 1.600
",
with 60cc combustion chambers. Spark plugs were located at the peak of the combustion chambers' wedge, between the exhaust ports; press-in heat shields protected them from the heat of the exhaust manifolds.
Cast iron exhaust manifolds, less restrictive than units found on previous engines, were bolted to the outboard side of each head. The new cylinder heads also featured stud-mounted rocker arms, a change from the shaft-mounted LA arms. This last change was due to the different oiling system of the new engine, as described in the next paragraph.
The valve covers on the Magnum have 10 bolts rather than the previous 5, for improved oil sealing.
In addition, the valve covers were made of thicker steel than earlier parts, and were installed with a silicone gasket.
The valvetrain was also updated, although it was still based on a single, center-block-located camshaft pushing on hydraulic lifters and pushrods, one for each rocker arm. However, the cast nodular iron camshaft was of the "roller" type, with each lobe acting upon a hydraulic lifter with a roller bearing on the bottom; this made for a quieter, cooler-running valvetrain, but also allowed for a more aggressive valve lift. Each of the lifters acted upon a steel pushrod, which were of the "oil-through" type. This was another change for the Magnum. Because the new pushrods also served to provide oil to the top of the cylinder head, the rockers were changed to the AMC-style, screw-mounted, bridged half-shaft type. The new rockers also had a higher ratio: 1.6:1 compared to 1.5:1 in the LA engine, which increased leverage on the valves.
In addition, the oil boss located at the end of the cylinder head on the LA engine was left undrilled, as it was no longer needed. However, the boss itself was left in place, perhaps to cut down on casting and machining costs, and to allow the use of earlier LA heads.
Engine timing was controlled by the all-steel, silent Morse timing chain (some early production engines had double-row roller timing sets), which was located beneath the aluminum timing cover at the front of the engine block. The timing chain sprockets, one each for the camshaft and crankshaft, were all-steel; for the last few years the LA engine came with nylon teeth on the sprockets. At the rear of the camshaft was cut a set of helical gear teeth, these being used to spin the distributor. Mounted to the front of the timing cover was a new-design counter-clockwise-rotation water pump, with much improved flow.
Externally, the accessory drive belt was changed to a serpentine system; coupled with an automatic belt tensioner this increased belt life, reduced maintenance and contributed to lower noise and vibration levels.
The ignition system was also all-new for the Magnum. Controlled by a new micro-processor-equipped Single-Board Engine Controller (SBEC, also known as the ECM, or Engine Control Module), the ignition system included a distributor mounted at the rear of the engine. A 36,000-volt ignition coil, usually located at the front right of the engine, provided electrical power to the center of the distributor cap, where a spinning rotor directed the power to each of the individual cylinders' spark plug wires. Ignition dwell, advance and retardation were electronically controlled by the SBEC.
The SBEC controlled the ignition, as well as the opening and closing of the fuel injectors. During cold startup, wide-open throttle and deceleration, it did this based on "open-loop", pre-programmed operating parameters. During normal idle and cruising, it began "closed-loop" operation, during which the module acted based upon inputs from a variety of sensors. The basic sensors that provided input to the SBEC included the Oxygen sensor (O2), Manifold Absolute Pressure (MAP) sensor, Throttle Position Sensor (TPS), Intake Air Temperature (IAT) sensor and Coolant Temperature sensor (CTS). The basic actuators controlled by the SBEC's outputs included the fuel injectors, ignition coil and pickup, and the Idle Air Control (IAC) valve. The latter controlled idle characteristics.
However, the SBEC also controlled the operation of the charging system, air conditioning system, cruise control and, in some vehicles, transmission shifting. By centralizing control of these systems, the operation of the vehicle was simplified and streamlined.
Emissions output was controlled by several systems. The EGR, or
Exhaust Gas Recirculation
In internal combustion engines, exhaust gas recirculation (EGR) is a nitrogen oxide () emissions reduction technique used in petrol/gasoline, diesel engines and some hydrogen engines. EGR works by recirculating a portion of an engine's exhaust ...
system, brought exhaust gas from the exhaust stream up to the intake manifold, lowering peak combustion temperatures, the goal being the reduction of NOX emissions.
A
PCV, or
Positive Crankcase Ventilation system, introduced oil vapor and unburnt fuel vapors from the crankcase to the intake, allowing the engine to re-use these as well.
Furthermore, gasoline vapors that would normally be released into the atmosphere were captured by the
EVAP system, to then be introduced into the engine.
In 1996, the
OBD-II on-board diagnostics system was introduced on all passenger vehicles in the United States, as per
United States Environmental Protection Agency
The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it ...
(EPA) regulation. As such, a new engine control computer was developed for vehicles powered by Magnum engines, known as the
JTEC.
The new
Powertrain Control Module was more complex and more intelligent, and added programming meant it could also control automatic transmission and other powertrain functions; its firmware could also be reprogrammed ("reflashed") via the same OBD-II port. With the introduction of the JTEC, the EGR system was dropped from Magnum engines.
Magnum 3.9 L V6
As the 5.2 L V8 was introduced in 1992, the often-forgotten V6 version of the Magnum engine became available in the Ram pickup and the more compact
Dodge Dakota
The Dodge Dakota, known as the Ram Dakota for the final two years of production, is a mid-size pickup truck from Chrysler's Ram (formerly Dodge Truck) division. The first Dakota was introduced in late 1986 as a 1987 model. From its introduction th ...
. Based on the LA-series V6, the 3.9 L featured the same changes and upgrades as the other Magnum engines. The 3.9 L can be better understood by imagining a 5.2 L V8 with two cylinders removed.
Power increased substantially to at 4,400 rpm and from at 3,200 rpm, as compared with the previous TBI engine. For 1994, horsepower was reduced to , mostly due to the installation of smaller-volume exhaust manifolds; torque ratings remained the same.
For 1997, the 3.9 L engine's torque output was increased to , with a compression ratio of 9.1:1.
Firing order was 1-6-5-4-3-2.
This engine was last produced for the 2003
Dodge Dakota
The Dodge Dakota, known as the Ram Dakota for the final two years of production, is a mid-size pickup truck from Chrysler's Ram (formerly Dodge Truck) division. The first Dakota was introduced in late 1986 as a 1987 model. From its introduction th ...
pickup. Starting in the 2004 model year it was entirely withdrawn from production and replaced with the 3.7 L
PowerTech V6 engine.
Applications:
* 1992–2003
Dodge Dakota
The Dodge Dakota, known as the Ram Dakota for the final two years of production, is a mid-size pickup truck from Chrysler's Ram (formerly Dodge Truck) division. The first Dakota was introduced in late 1986 as a 1987 model. From its introduction th ...
* 1992–2003
Dodge Ram Van/
Dodge Ram Wagon
* 1992–2001
Dodge Ram
The Ram pickup (marketed as the Dodge Ram until 2010) is a full-size pickup truck manufactured by Chrysler, Stellantis North America (formerly Chrysler Group LLC and FCA US LLC) and marketed from 2010 onwards under the Ram Trucks brand. The cur ...
Magnum 5.2 L V8

The Magnum 5.2 L, released in 1992, was an evolutionary development of the 'LA' engine with the same displacement. The 5.2 L was the first of the Magnum upgraded engines, followed in 1993 by the 5.9 L V8 and the 3.9 L V6.
At the time of its introduction, the 5.2 L Magnum created at 4,100 rpm and at 3,000 rpm.
Production of this engine lasted until 2002, when it was completely replaced by the newer 4.7 L
PowerTech SOHC V8 engine.
General characteristics:
*Engine Type: 90° V-8 OHV 2 valves per cylinder
*Bore & Stroke:
*Displacement:
*Firing Order: 1-8-4-3-6-5-7-2
*Compression Ratio: 9.1:1 due to 62cc combustion chambers of Magnum heads
*Lubrication: Pressure Feed - Full Flow Filtration
*Engine Oil Capacity: with Filter
*Cooling System: Liquid - Forced Circulation - Ethylene Glycol Mixture
* 1992–2000
Dodge Dakota
The Dodge Dakota, known as the Ram Dakota for the final two years of production, is a mid-size pickup truck from Chrysler's Ram (formerly Dodge Truck) division. The first Dakota was introduced in late 1986 as a 1987 model. From its introduction th ...
* 1992–2001
Dodge Ram
The Ram pickup (marketed as the Dodge Ram until 2010) is a full-size pickup truck manufactured by Chrysler, Stellantis North America (formerly Chrysler Group LLC and FCA US LLC) and marketed from 2010 onwards under the Ram Trucks brand. The cur ...
* 1998–2000
Dodge Durango
* 1992–1993
Dodge Ramcharger
The Dodge Ramcharger is a large sport utility vehicle built by Dodge from 1974 to 1993, based on a shortened-wheelbase version of the Dodge D Series/ Ram pickup truck chassis. A Plymouth version, named the Plymouth Trail Duster, offered from 1974 ...
* 1992–2002
Dodge Ram Van
* 1993–1998
Jeep Grand Cherokee
5.9 L Magnum V8
In 1993, Chrysler Corporation released the next member of the Magnum family: the 5.9 L V8. This was based on the LA-series engine, and included the same upgrades and design features as the 5.2 L. The standard 5.9 L produced at 4,000 rpm and at 3,200 rpm; torque was increased to at 2,800 rpm in the heavy-duty version.
It was upgraded in 1998 to at 4,000 rpm and at 3,250 rpm. The 5.9 L came factory-installed in 1998-2001
Dodge Dakota
The Dodge Dakota, known as the Ram Dakota for the final two years of production, is a mid-size pickup truck from Chrysler's Ram (formerly Dodge Truck) division. The first Dakota was introduced in late 1986 as a 1987 model. From its introduction th ...
R/T pickups and 2000-2003
Dodge Durango R/T SUVs. It was also installed in the
Jeep Grand Cherokee Limited 5.9, only available in 1998. The 5.9 L Magnum was available until the 2003 model year, when it was replaced with the 5.7 L
Hemi V8 engine.
Magnum 5.9L
Although the pre-Magnum ('71-'92) and Magnum versions of the are both externally balanced, the two are balanced differently (the 360 Magnum uses lighter pistons) and each requires a uniquely balanced damper, flywheel, drive plate, or torque converter. Bore and stroke size was ; compression ratio was 9.1:1.
* 1998–2003 Dodge Dakota
The Dodge Dakota, known as the Ram Dakota for the final two years of production, is a mid-size pickup truck from Chrysler's Ram (formerly Dodge Truck) division. The first Dakota was introduced in late 1986 as a 1987 model. From its introduction th ...
* 1992–2002 (and early 2003 models) Dodge Ram
The Ram pickup (marketed as the Dodge Ram until 2010) is a full-size pickup truck manufactured by Chrysler, Stellantis North America (formerly Chrysler Group LLC and FCA US LLC) and marketed from 2010 onwards under the Ram Trucks brand. The cur ...
* 1992–2003 Dodge Ram Van/ Dodge Ram Wagon
* 1998–2003 Dodge Durango
* 1992–2001 Dodge Ramcharger
The Dodge Ramcharger is a large sport utility vehicle built by Dodge from 1974 to 1993, based on a shortened-wheelbase version of the Dodge D Series/ Ram pickup truck chassis. A Plymouth version, named the Plymouth Trail Duster, offered from 1974 ...
* 1998 Jeep Grand Cherokee 5.9 Limited
8.0 L Magnum V10
As the design for the 5.2 L Magnum V8 was coming together in 1988, consideration was given to the design of a larger V10 iteration, mainly intended for use in Dodge Ram
The Ram pickup (marketed as the Dodge Ram until 2010) is a full-size pickup truck manufactured by Chrysler, Stellantis North America (formerly Chrysler Group LLC and FCA US LLC) and marketed from 2010 onwards under the Ram Trucks brand. The cur ...
2500 and 3500 pickups. This was to be Chrysler's first 10-cylinder engine (before the '92 Viper, see below), and can best be understood as a 5.9 L V8 with two cylinders added. This engine was based on a cast iron block, and was rated for at 4,100 rpm and at 2,400 rpm. Bore and stroke was ; compression ratio was 8.4:1; firing order was 1-10-9-4-3-6-5-8-7-2. Valve covers were die cast magnesium (AZ91D alloy), rather than stamped steel; this lowered noise levels and made for better gasket sealing.
The 8.0 L Magnum V10 first became available in the 1994 model year Dodge Ram 2500 and 3500 pickups, and it was the most powerful gasoline-burning engine then available in any passenger pickup truck. The engine lasted through the 2003 model year, after which it was discontinued.
Applications:
* 1994-2003 Dodge Ram
The Ram pickup (marketed as the Dodge Ram until 2010) is a full-size pickup truck manufactured by Chrysler, Stellantis North America (formerly Chrysler Group LLC and FCA US LLC) and marketed from 2010 onwards under the Ram Trucks brand. The cur ...
2500/3500 Pickup
Magnums today
Chrysler offers a line of crate engines based on the Magnum designed to bolt into older muscle cars and street rods with little modification. Some of the changes to facilitate this were using a 1970-93 water pump so that older pulleys and brackets could be used, as well as an intake manifold that uses a carburetor
A carburetor (also spelled carburettor) is a device used by an 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 venturi tube in the main meter ...
instead of electronic fuel injection
Manifold injection is a mixture formation system for internal combustion engines with external mixture formation. It is commonly used in engines with spark ignition that use petrol as fuel, such as the Otto engine, and the Wankel engine. In a m ...
. With a high lift cam and single plane intake, the crate Magnum was rated at with the Magnum heads. Later models equipped with "R/T" or aluminum cylinder heads produced . A bolt-in fuel injection conversion kit is also available.
Identifying a Magnum engine
The easiest way to differentiate a bare Magnum block from a LA is by checking for the presence of the two crankshaft position sensor mounting bosses on the right rear top of the block, just to the rear of the cylinder head deck surface. Bosses = Magnum. Keeping in mind that the earlier TBI engines also have crank sensors in this position.
All Magnum engines were stamped with a unique engine ID number. This was located on a flat impression on the cylinder block's right side, near the oil pan gasket surface. From 1992 to 1998, the ID was 19 digits long. An example would be:
4M5.2LT042312345678
-The "4" is the last digit of the model year of the engine. This example is a 1994.
-The "M" stands for "Mound Road", the plant where the engine was assembled. Other characters found here would be "S" for Saltillo, "T" for Trenton and "K" for Toluca.
-5.2L has an obvious meaning here: the displacement of the engine in liters.
-The seventh character, here a "T", was the usage of the engine. "T" translates to truck usage.
-0423 would mean the engine was produced on April 23.
-The final eight digits, here shown as "12345678" are the serial number of the engine.
From 1998 to 2003, the engine ID was shortened to only 13 characters. It differed in that engine displacement was given in cubic inches rather than in liters, the usage character was dropped and the serial number was four instead of eight digits long.
To add some confusion, not only was the name Magnum used on Dodge passcar hi-po engines 1967-1970s, and vehicle lines in the late 1970s and 2000s, it was also applied 4.7L power tech v8 (1999+) and to the 5.7L "Hemi" V8 in pickup trucks (2003+).
See also
* Viper engine
* Chrysler engines
* Chrysler A engine
* Chrysler Hemi engine
References
{{DEFAULTSORT:Chrysler La Engine
LA
V6 engines
V8 engines
V10 engines
Gasoline engines by model