The American Motors Corporation (AMC) used V8, straight-6, V6, and straight-4 engines in various passenger automobiles and Jeep vehicles from 1954 through 2006. Some engines were of AMC design or inherited from its constituents. Others were bought from, or had their design bought from other manufacturers.
Four Cylinder EnginesEdit
American Motors used several four-cylinder engine designs.
The 108 cu in (1.8 L) an AMC designed air-cooled V4 engine that was used in AMC's lightweight, aluminium-bodied M422 'Mighty Mite' military vehicle, built from January 1960 to January 1963 as an air transportable (by the helicopters of the time) Jeep for the U.S. Marine Corps. This engine was unsuitable for regular passenger car use mainly due to its relatively small displacement and power output.
- Bore & Stroke: 3 1/4 inch x 3 1/4 inch
- Compression: 7.5:1
- Horsepower: 52 hp @ 3,600 rpm
- Torque: 90 lb-ft @ 2,500 rpm
The 121 Cu in was an advanced design overhead camshaft four-cylinder engine bought from Audi/Volkswagen 1977 through 1979. Though a small engine, its advanced design created reasonable power for its size and due to being an OHC engine, it had a high redline. This engine was also used in the Audi 100, Volkswagen LT van, and Porsche 924. The engine was built to AMC specs, which are different from Audi/VW/Porshe specifications. AMC used a carburetor and standard points ignition as well as slightly larger clearances.
The original deal was for AMC to buy the design, eventually moving manufacturing to the United States. American Motors bought a plant specifically to build the engine, but never sold enough to move complete manufacturing. The AMC engines were assembled in the U.S. from major castings supplied by VW, hence the different assembly clearances. As part of the agreement, AMC was not to use the VW or Audi names when referring to the engine. Everyone familiar with the design knew they were virtually identical, and the automotive press commonly referred to them as Audi or VW engines, just as we do in this article. VW/Audi/Porsche U.S. spec engines produced 110 hp in mid-1977; earlier models produced 95 hp -- 15 hp to 30 hp less than the AMC version.
- Bore x Stroke 3.41" x 3.32"
- Compression Ratio 8.1:1
- Horsepower (net) 80 hp @ 5,000 rpm
- Torque (net) 105 lb-ft @ 2,800 rpm
It was used in the AMC Gremlin, AMC Spirit, and AMC Concord, The only Jeep this engine was used in was the 1979 DJ5G (Postal delivery). In the DJ5G it was mated to a 3sp 904 automatic transmission with a VW/Audi pattern bell. In the manual shifted cars it was mated to a BorgWarner HR-1 4-speed transmission.
It shares the bellhousing pattern with several German cars, it does not share the bellhousing pattern with the VW Rabbit diesel line of engines.
Renault 126 Turbo Diesel Edit
The Renault-developed 126 cu in (2.1 L) 4 cylinder Turbo Diesel was an optional engine used in AMC's Jeep line between 1984 and 1986. It was mated to a standard four-speed or optional five-speed manual, and with either transmission delivered exceptional fuel economy. For a diesel of this size at that time, power delivery was respectable, at 85 hp @ 3750 RPM, 132 lb-ft @ 2750 RPM. The engine was also known for relatively instant pedal response at a time when both diesel- and turbocharger-equipped engines generally were known for a noticeable lag. Weighing in at a scant 331 pounds, it also featured first-tier technology for the time such as an intercooler and an overhead cam. When it reached market, it marked the first time a turbocharged diesel was offered in a sports-utility vehicle in the United States.
Pontiac 151 Edit
The 151 cu in (2.5 L) is commonly referred to as the "Iron Duke" and is a Pontiac design. It was purchased by AMC from 1979 through 1983 as the base option in the RWD Spirit and Concord, the AWD Eagle models, economy versions of Jeep CJs, and in postal Jeeps. This early version used a Chevrolet small block V-8 bell housing bolt pattern. 1984 and later model GM 151s used the corporate GM four cylinder/small V-6 bolt pattern (not used by AMC).
- Bore x Stroke 4.00" x 3.00"
- Compression Ratio 8.2:1
- Horsepower (net) 82 hp @ 4,000 rpm
- Torque (net) 125 lb-ft @ 2,600 rpm
In 1984 AMC introduced their own four cylinder engine design. All previous fours (with the exception of the Air-Cooled 108) were purchased for interim use. For more information follow the link below.
- Main article: AMC Straight-4 engine
Six Cylinder EnginesEdit
- Main article: AMC Straight-6 engine
Nash and Hudson BeginningsEdit
When Nash and Hudson merged to form AMC in 1954 all the Hudson bodies were dropped for the 1955 model year. The Ambassador and Statesman received a hasty grille/taillight/trim/dash restyling to create the new Hudson Hornet and Wasp. The Nash Ambassador Six retained the Nash 252.6 OHV six for 55 and 56, V-8 only for 1957. The Nash OHV six, dating back to 1934, was a totally different design than the Rambler 195.6. Hudson six cylinder cars retained the Hudson L-head six, 308 CID in the Hornet and 202 CID in the Wasp. This was the only major Hudson component left - it dated back to the 40s. All Rambler models, whether badged Hudson or Nash, used the Rambler 195.6.
This motor was originally a Nash design dating back to 1940. AMC used an L-head (flat-head, 1955, 1958-65) and OHV (1956-65) version, as well as an aluminum block version (1961-63). All shared the same bore and stroke as well as some other features/components. For more information see AMC Straight-6 engine.
- Main article: Jeep Tornado engine
While not an AMC design and never used in an AMC vehicle, this engine is included because it is often confused with the AMC/Jeep 232, which Kaiser Jeep purchased to replace the SOHC Kaiser engine 230 cu in (3.8 L) in 1965. The Tornado first appeared in civilian Jeep vehicles in 1963 and was only used until 1965. The US Army M-715 and derivatives used it through the 60s and early 70s. The AMC and Kaiser engines do not share bellhousing bolt patterns. Cam trouble on the 230 was common due to oils that weren't yet up to the task back then.
With its over-square bore and stroke, it was very much built for low rpm torque. It was a very dependable engine with reports of them going 250,000 mi. with no major problems -- with proper maintenance. Production continued through 1983 in Argentina at Industrias Kaiser Argentina. There is was used in several AMC sourced cars and Kaiser Jeeps. Jeep didn't become part of AMC until 1970.
- Main article: Buick V6 engine
The "Dauntless" 225 cu in (3.7 L) V6 engine was introduced in the 1966 Kaiser CJ and as an option in the C101 Jeepster Commando. Kaiser bought the tooling from Buick to build the 225 during the short period prior to selling their Jeep subsidiary to AMC.
AMC retained the Buick engine briefly after it bought Jeep. It was retired in 1971, shortly after the 1970 acquisition. The tooling was then sold back to General Motors in 1974, and this engine continues to be used today.
The engine was an odd-fire V6, meaning that TDC for the cylinders was not evenly spaced around the engine but grouped in pairs. The engine was known at the time for its power and reliability. It would idle slowly, but not as smooth as other engines, especially the inline sixes.
This engine was used in the following vehicles:
The Modern Era I-6Edit
American Motors designed an entirely new six cylinder for 1964, and this version was in constant production by AMC and Chrysler through 2006. See AMC Straight-6 engine.
- 199 cu in (3.3 L)
- 232 cu in (3.8 L)
- 258 cu in (4.2 L)
- 4.0 L
The bell pattern was different for the early motors from the AMC V8s. In '71 AMC raised the block height and increased the stroke on the 199 and early 232 motors. The 199 became 232 cubic inches and the old 232 became 258. In '71 only these two RB or "raised block" engines shared the small bell pattern of the earlier engines. In '72 both 232 and 258 changed bell pattern to match AMC V8s, at the same time AMC switched from Borg-Warner to Chrysler automatic transmissions.
General Motors V6Edit
- Used in the 1984-1986 Jeep Cherokee (XJ)
- Main article: AMC V8 engine
Prior to introducing an in-house designed V-8 AMC purchased V-8s from Packard. They were only used in 1955-56 Nash Ambassadors and Hudson Hornets. The 320 was used in 1955, 352 in 1956. Late in 1956 AMC introduced their GEN-1 design as a 250, used only in Ambassador and Hornet Specials. The Specials were actually the slightly smaller and lighter Statesman/Wasp two door hardtop bodies with Ambassador/Hornet trim. The Packard engines were dropped after 1956. All Packard V-8s came exclusively with the Packard Ultramatic automatic transmission. Packard UltramaticTransmission
AMC went through three generations of its V8 Block, though the most famous are its third generation blocks used in muscle cars. Generally, GEN-2 and 3 AMC V8s are considered "Small Block" due to exterior size and their maximum displacement. The GEN-1 engine is rather bulky and heavy for its displacement. It compares in size and weight to a "Big Block". Technically there is no "big" and "small" block AMC V-8s -- there was only one design in production at any given time. All AMC designed V-8s share one thing -- a common bore center of 4.75". This is the same as Chrysler Big Block V-8s, and more similar to other big blocks than small blocks. Most other features, at least of the GEN-2 and 3 models, are more typical of small block designs.
GEN-1 Nash/Hudson/Rambler V8s (1956-1966) Edit
- 250 cu in (4.1 L)
- 287 cu in (4.7 L)
- 327 cu in (5.4 L)
GEN-2 AMC Short-Deck V-8 (1966–1970) Edit
- 290 cu in (4.8 L)
- 343 cu in (5.6 L)
- AMX 390 cu in (6.4 L)
GEN-3 AMC Tall-deck (1970-1991)Edit
- 304 cu in (5 L)
- 360 cu in (5.9 L)
- 390 cu in (6.4 L)
- 401 cu in (6.6 L)
- AMC Straight-4 engine
- AMC Straight-6 engine
- AMC V8 engine
- AMC/Jeep Transmissions
- List of Chrysler engines
- AMC Rambler Car Club