The LA engine (Late A engine) was an evolution of the small-block Plymouth polyspheric-head A engine. It continues through this day in the form of the Dodge Viper V10, 3.9 L V6, 5.2 L and 5.9 L V8. All LA engines are pushrod OHV designs and use a 90° V block. The heads are wedge-shaped, rather than the polyspherical heads in the Plymouth A engine or the hemispherical heads in the Chrysler Hemi engine. All are cast iron, except for the Viper V10, which is aluminum. LA engines have same 4.46" bore spacing as the A family.

The LA family was rebranded as the Magnum V6 and V8 in the 1990s. All but the Viper and Ram Tough V10s were replaced by the new PowerTech V6 and V8 and Hemi V8 in the early 2000s.

Production of the LA series was long handled by the Mound Road Engine factory in Detroit, Michigan. With most versions cancelled, that plant was closed in 2002.

273

The LA 273 (4.5 L) was the first LA engine, debuting in 1964 and retiring in 1969. It had a 3.625 in (92 mm) bore and 3.31 in (84 mm) stroke. It had a mechanical solid lifter valvetrain until 1968 when it switched to the hydraulic valvetrain used in the LA 318. A special high performance version of the 273 was created in 1966. It used a 0.500" lift solid-lifter camshaft, steel-tube header exhaust, and a Holley 4-barrel carburetor, producing 275 horsepower (1 hp/cid). It was available in the Dart only, and the car was dubbed the "D-Dart".

The 273 was used in:

• Dodge Dart
• Plymouth Barracuda
• Plymouth Belvedere
• Dodge Coronet
• Plymouth Satellite
• Plymouth Valiant

318

The LA 318 was a 318 in³ (5.2 L) relative of the A 318. Like the A 318, it has a larger bore at 3.91 in (99 mm). It appeared shortly after the 273, in 1967, and proved tremendously successful. An evolution of this engine was available until the early 2000s when it was retired.

This engine was used in the following vehicles:

• 1984-1989 Chrysler Fifth Avenue
• Chrysler Valiant
• 1977-1981 Chrysler LeBaron
• Dodge Challenger
• Dodge Coronet
• Dodge Dart
• Dodge Diplomat
• 1991 Dodge Dakota
• Dodge Aspen
• Dodge Demon
• Dodge Dart Sport
• Dodge Ram
• Dodge Ramcharger
• Plymouth Fury
• Plymouth Valiant
• Plymouth Satellite
• Plymouth Gran Fury
• Plymouth Belvedere
• Plymouth Volare
• Plymouth Barracuda
• Plymouth Duster

340

As the Detroit horsepower wars heated up in the mid 60's, Chrysler decided to produce a small block V8 specifically designed for high performance applications. They wanted a lightweight, high output engine that was equally at home at the drag strip or on an oval track. Thus, the legendary 340 was born.

Performance Design:

Starting with their tried and true 318 LA small block, Chrysler engineers increased the cylinder bores to 4.04 inches (103 mm) while keeping the 318's 3.31 inch stroke. Anticipating higher loads resulting from racing operation, the engineers fitted a forged steel crankshaft instead of the cast one used in the 318. A 4-Barrel carburetor was mated to a high-rise, dual plane intake manifold. This induction setup fed into a set of cylinder heads that are still considered one of the best of that era. The heads were high-flow with big ports, and used 2.02/1.60 inch intake and exhaust valves. An aggressive cam was fitted to take advantage of the much better breathing top end. 1968 4-Speed cars got an even hotter cam, but it was discontinued in 1969. Using flat-top pistons, the 340's compression ratio was 10.5:1, placing it near the limit of what was possible on pump gas. On top of all this, 340 customers also got a dual timing chain, windage tray and a revised oil pump as standard equipment. The result was an incredibly potent powerplant.

Performance Characteristics:

Like many other performance V8's of the day, for insurance reasons, the 340 engine was underrated at 275 hp (205 kW) with a single four-barrel carburetor and 290 hp (216 kW) with three two barrels. However, in reality both configurations could produce at least 315 to 320 hp (235 to 239 kW). On the street, the 340 delivered as promised. The engine was simply a screamer and many a big block driver found themselves shaking their heads after being beaten by the little Chrysler small block. Within the Chrysler family, the 340 gave nothing away to the 383 on the strip, and totally outclassed it when it came to handling. When coupled with lightweight A and E-Bodies, the 340 setup was a born street-fighter that was equally at home on the track. The engine was praised as a high-winder with good durability, making it popular with circle-track racers. The most potent street version was the "Six Pack" 340, found in the Challenger T/A and AAR 'Cuda.

History:

Due to the combination of rising gas prices and insurance company crackdown on high-performance vehicles, the 340 did not live long. The LA 340 (5.6 L) first appeared in 1968. In 1972, Chrysler dropped the compression ratio to a tame 8.5:1 and used smaller intake valves in the heads, which greatly reduced the engine's output. The engine lingered for a year, but was finally retired in 1973, as the musclecar era was over and Chrysler no longer had a need for a high performance small block. However, some parts from the 340 lived on in Chrysler's 360 truck engine, which was only recently retired in favor of the new Hemi small block.

This engine was used in the following vehicles:

• Chrysler Valiant Charger (Australia)
• Dodge Challenger
• Dodge Charger
• Dodge Dart
• Dodge Super Bee
• Plymouth Barracuda
• Plymouth Duster
• Plymouth Road Runner

This engine was also powering the French Monica 560.

360

The LA 360 (5.9 L) is version of the LA block bored and stroked to 4.00 by 3.58 in (102 by 91 mm). It appeared in 1971, and was sold until 2003 (known as the Magnum 5.9). It was replaced by the LA-based 5.7 345 Hemi.

This engine was used in the following vehicles:

• Various Bristols (in Bristol-modified form)
• Chrysler 300
• Chrysler Valiant & Valiant Charger (Australia)
• Chrysler by Chrysler (Australia)
• 1975-1979 Chrysler Cordoba
• 1978-1979 Chrysler LeBaron
• 1977-1981 Chrysler New Yorker
• 1971-1981 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
• 1981-1991 Dodge Ram
• 1979-1991 Dodge Ram Van/Dodge Ram Wagon
• 1971-1978 Dodge Sportsman/Dodge Tradesman
• 1974-1991 Dodge Ramcharger
• 1974 Plymouth Barracuda
• 1974-1976 Plymouth Duster
• 1971-1978 Plymouth Fury
• 1975-1977, 1980 Plymouth Gran Fury
• 1974-1983 Plymouth Voyager
• 1979-1981 Dodge St. Regis
• 1976-1980 Plymouth Volare

238

The 238 V6 is a 238 in³ (3.9 L) V6. It derives from the 318 V8. It debuted in 1987. Output was 125 hp (93 kW) until it was replaced by the Magnum 3.9 starting in 1992.

Applications:

• 1987-1991 Dodge Dakota

Magnum 4.7

The Magnum 4.7 is a rebranded Chrysler PowerTech 4.7 made available in Dodge vehicles.

Applications:

• 200x- Dodge Ram
• 2004-present Dodge Durango
• 2000-present Dodge Dakota

Magnum 5.2

The Magnum 5.2 is an evolution of the 318 with the same displacement. It received the Magnum V8 name with new manifolds and heads in 1992. Major changes that year include the addition of multiport fuel injection, a new higher-flow valve angle, increased valve lift, and larger exhaust. Power was up to 230 hp and 325tq (172 kW), with 300 ft·lbf of torque, from 170 hp (127 kW) previously. Production of the Magnum 5.2 ended with the 2003 model year Dodge Ram Van. It was replaced by the new 4.7 L PowerTech V8 offered in 2002 Dodge Ram pickups, 1999 Jeep Grand Cherokees, and 2000 Dodge Dakota pickups.

Applications:

• 1992-1999 Dodge Dakota
• 1992-2001 Dodge Ram
• 1998-2000 Dodge Durango
• 1992-1993 Dodge Ramcharger
• 1992-2003 Dodge Ram Van
• 1993-1998 Jeep Grand Cherokee

Magnum 5.9

The Magnum 5.9 is an evolution of the 360. It got the Magnum V8 name with the same new manifolds, heads, and fuel injection as the 5.2 for 1993. power output that year was 230 hp (172 kW), with 325 ft·lbf (441 N·m) of torque. The engine eventually reached 250 hp (183 kW) and 345 ft·lbf (465 N·m) of torque in later years or production. Starting in 2003, the 5.7 L Hemi V8 began replacing this engine.

Applications:

• 1998-2003 Dodge Dakota
• 1992-2003 Dodge Ram (only available in 1500 models for 2003)
• 1992-2003 Dodge Ram Van/Dodge Ram Wagon
• 1998-2003 Dodge Durango
• 1992-1993 Dodge Ramcharger
• 1998 Jeep Grand Cherokee Limited

Magnum 3.9

The 3.9 V6 is a 318 with two cylinders removed. It replaced the 238 with the Magnum name in 1992, with the same changes as the Magnum V8s. Power increased substantially, from 125 hp (93 kW) to 180 hp (134 kW). This engine was last produced for the 2003 Dodge Dakota pickup. Starting in the 2004 model year it was entirely removed from production and replaced with the 3.7 L PowerTech V6 engine, which itself was a cut-down version of the 4.7 L PowerTech V8.

Applications:

• 1992-2003 Dodge Dakota
• 1992-2003 Dodge Ram Van/Dodge Ram Wagon
• 1992-2001 Dodge Ram

Viper V10

The Viper V10 is loosely based on the rest of the LA family, and appeared with the Dodge Viper in 1992. It can be thought of as a Magnum 5.9 with two extra cylinders and a longer stroke of 3.88 in (99 mm).

Originally designed as a truck engine, Lamborghini revamped Dodge's cast-iron block V10 for the Viper by recasting the block and head in aluminium alloy, giving the engine a significant power boost. Some within Lamborghini felt that the pushrod two-valve design, while adequate for the truck application for which the engine was originally created, was unsuitable for a performance car. However, Chrysler was uncertain about the Viper's production costs and sales potential and so declined to provide the budget for the modification.

The engine produced 400 hp (298 kW) and 490 ft·lbf (664 N·m) of torque. The second-generation engine produced 450 hp and 490 ft·lbf. The third-generation engine (starting with 2003 Viper) continues to use this engine, but now with 510 hp and 535 ft·lbf.

Production of the V10 engine started at Mound Road Engine before moving to Conner Avenue Assembly in May 2001. This is the same facility that produces the Viper itself. In addition, the Viper V10 found its way back into the Ram with the Ram SRT-10 model, earning the truck the Guiness World Record for fastest production truck. A limited run (10) of the Dodge Tomahawk motorcycle also uses this engine.

Ram Tough V10

Orginally developed in the 1980s as a truck engine used for the larger size Rams, the V10 was re-engineered as the engine of the Dodge Viper in 1990 by Lamborghini, then owned by Chrysler, and used in the Ram 2500. It was a rare engine and provided far less power than the rebuilt model in the Viper. It was used in Dodge trucks and was called the Ram Tough V10 Magnum.