The LA engine is a family of overhead-valve small-block 90° V-configured gasoline engines built by Chrysler Corporation between 1964 and 2003. Primarily V8s, the line includes a single V6 and V10, both derivations of its Magnum series introduced in 1992. A replacement of the Chrysler A engine, they were factory-installed in passenger vehicles, trucks and vans, commercial vehicles, marine and industrial applications. Their combustion chambers are wedge-shaped, rather than polyspheric, as in the A engine, or hemispheric in the Chrysler Hemi. LA engines have the same bore spacing as the A engines.
LA engines were made at Chrysler's Mound Road Engine plant in Detroit, Michigan, 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 U.S. and through 1967 in export vehicles when the "A" 318 engine was phased out.
The basic design of the LA engine would go unchanged through the development of the "Magnum" upgrade (1992–1993), and continue into the 2000s with changes to enhance power and efficiency.
239 V6 The V6 was introduced with the Dodge Dakota for 1987, and replaced the older, longer Slant-Six in the Dodge Ram trucks and vans for 1988. It is essentially a six-cylinder version of the 318 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 3.9 L Magnum starting in 1992. In 1987, it used a two-barrel Holley carburetor and hydraulic valve lifters. In 1988, it was upgraded with throttle-body fuel injection and roller lifters. For the 1992 Magnum update, the throttle-body fuel injection was upgraded to a multi-port fuel injection system. In 1997, it was then upgraded to sequential fuel injection. The engine was produced through 2003 before it was replaced with the 3.7 L PowerTech V6.
1987–2003 Dodge Dakota 1988–2001 Dodge Ram 1988–2003 Dodge Ram Van
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 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 from 1965 to 1967; called the "Commando", it was standard in the Barracuda Formula S model and optional in all other compact models excluding station wagons. It featured a 4-barrel 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, and special black wrinkle valve covers with extruded aluminum appliqués. It was fitted to a low-restriction exhaust system with a exhaust pipe, collector-type Y-junction, and exposed resonator. For 1965 (only), the muffler was of "straight through" construction.
A special version, exclusive to the 1966 Dodge Dart, was available. It used a lift solid-lifter camshaft, fabricated-steel-tube exhaust, and a Holley 4-barrel carburetor, producing (1 hp/cu in). 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 1964–1969 Plymouth Barracuda Plymouth Belvedere Dodge Coronet Plymouth Satellite 1964–1969 Plymouth Valiant 1966–1967 Ghia 450 SS
318 V8 The LA 318 has a bore and stroke of , identical to the A 318 it was derived from. 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. It used hydraulic lifters and a two-barrel carburetor for most of its production, though four-barrel Carter Thermo-Quad and Rochester Quadrajet carburetors were used in police applications starting in 1978 and 1985, respectively. The 318 two-barrel ELD received roller lifters and a fast-burn chambered cylinder head in 1985 (the four-barrel police ELE 318 continued to use modified J heads and hydraulic flat valve lifters through 1989).
Throttle-body electronic fuel injection was factory equipment on the 1981–1983 Imperial. From 1988 to 1991, another throttle-body fuel injection system was used for truck and van applications.
1983–1989 Chrysler Fifth Avenue 1981–1983 Imperial 1968–1981 Chrysler Valiant 1977–1981 Chrysler LeBaron 1979–1982 Chrysler New Yorker 1981–1983 Imperial 1975–1983 Chrysler Cordoba 1976–1980 Dodge Aspen Dodge Charger Dodge Challenger Dodge Coronet 1968–1976 Dodge Dart 1977–1989 Dodge Diplomat 1991–1992 Dodge Dakota 1971–1972 Dodge Demon 1973–1976 Dodge Dart Sport 1970–1980 (Valiant) Dodge Super Bee (Mexico) 1971–1979 Dodge GTX (Argentina) 1978–1979 Dodge Magnum 1980–1983 Dodge Mirada 1967–1992 Dodge Ram Dodge Ram Van 1974-1992 Dodge Ramcharger 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 1968–1976 Plymouth Valiant 1976–1980 Plymouth Volaré 1981–19?? Allard J2X2 1976-1979 Monteverdi Safari 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 its 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 steel 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 introduced a special triple carburetor version of the 340 with triple 2-barrels at gross. Exclusively called the catchy Six-Pack on the Trans-Am targeted Dodge Challenger TA models, the same configuration was used by Plymouth for its Trans-Am AAR 'Cuda, called just the "340-6" or "six barrel". This race-oriented version of the already high-performance 340 featured an aluminum intake manifold mounting three Holley carburetors, a dual points ignition system, and 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.
The combination of increasingly stringent emission controls, lowered octane, rising gasoline prices, and insurance company crackdown on high-performance vehicles saw the relatively expensive 340 detuned 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 1971–1972 Dodge Demon Dodge Super Bee Plymouth Barracuda Plymouth Duster Plymouth Road Runner Plymouth Sport Fury GT Monica 560
360 V8
The LA has a bore and stroke of . It was released in 1971 with a two-barrel carburetor. 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-barrel dual-exhaust version, at SAE net, it 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.
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, but 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 (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 1974–1976 Dodge Dart 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 1979–1992 Dodge Ram Van/Dodge Ram Wagon 1971–1992 Dodge Sportsman/Dodge Tradesman 1974–1992 Dodge Ramcharger 1974–1981 Plymouth Trail Duster 1974–1975 Plymouth Road Runner 1974 Plymouth Barracuda 1974–1976 Plymouth Duster 1971–1978 Plymouth Fury 1975–1977, 1980 Plymouth Gran Fury 1976–1980 Plymouth Volaré 1974–1983 Plymouth Voyager 1979–1980 Dodge St. Regis 1978–1979 Dodge Li'l Red Express (in Bristol-modified form) Bristol 603 Bristol 412 (in Bristol-modified form with turbocharger) Bristol Beaufighter Bristol Brigand Bristol Beaufort
Throttle-body injected LA engines