The
American Motors Corporation (AMC) straight-6The straight-six engine or inline-six engine is a six cylinder internal combustion engine with all six cylinders mounted in a straight line along the crankcase. The single bank of cylinders may be oriented in either a vertical or an inclined plane with all the pistons driving a common crankshaft...
family of engines was used by a number of AMC and
JeepJeep is an automobile marque of Chrysler. It is the oldest off-road vehicle brand, with Land Rover coming in second. The original vehicle which first appeared as the prototype Bantam BRC became the primary light 4-wheel-drive vehicle of the US Army and allies during the World War II and postwar...
vehicles from 1964 through 2006.
- For an outline of all engines used by AMC see
195.6
American Motors' first straight-six engine was the . It was produced from 1958 through 1965 in both
overhead valveAn overhead valve engine, also informally called pushrod engine or I-head engine, is a type of piston engine that places the camshaft within the cylinder block , and uses pushrods or rods to actuate rocker arms above the cylinder...
(OHV) and "
flatheadA flathead engine or sidevalve engine is an internal combustion engine with valves placed in the engine block beside the piston, instead of in the cylinder head, as in an overhead valve engine...
" (L-head) side-valve versions.
Sometimes referred to as the
196 engine, this engine was originally designed by
NashAlso see: Kelvinator and American Motors CorporationNash Motors was an automobile manufacturer based in Kenosha, Wisconsin, in the United States from 1916 to 1938. From 1938 to 1954, Nash was the automotive division of the Nash-Kelvinator Corporation...
in the 1930s as a flathead, and redesigned as an OHV engine in 1956. The flathead version was discontinued for 1956 and 1957, but reemerged in 1958 as the economy engine for the "new"
Rambler AmericanThe Rambler American was an automobile manufactured by the American Motors Corporation between 1958 and 1969. The American was the second incarnation of AMC's forerunner Nash Motors second generation Rambler compact that was sold under the Nash and Hudson Motors marques from 1954 and 1955.The...
. When the engine was changed to an OHV configuration the water pump was moved from the left side of the engine (driven by a shaft extending from the back of the generator) to the front above the timing chain. When the flathead model was reintroduced it also received the new water pump. Equipped with such high quality parts as
forgeA forge is the workplace of a smith or a blacksmith. A forge is sometimes referred to as a smithy.The basic smithy contains a forge, also known as a hearth, for heating metals. The forge heats the workpiece to a malleable temperature or to the point where work hardening no longer occurs. The...
d
crankshaftThe crankshaft, sometimes casually abbreviated to crank, is the part of an engine which translates reciprocating linear piston motion into rotation...
s and
connecting rodIn a reciprocating piston engine, the connecting rod or conrod connects the piston to the crank or crankshaft.- History :The earliest evidence for a connecting rod appears on a late 3rd century AD Roman relief of a saw mill from Hierapolis, Asia Minor, as well as two 6th century Roman saw mills...
s, these engines earned a reputation for remarkable durability. The flathead, however, was prone to the typical flathead problem of overheating under sustained heavy load. This was from the hot exhaust traveling through the
cylinder blockThe cylinder block or engine block is a machined casting containing cylindrically bored holes for the pistons of a multi-cylinder reciprocating internal combustion engine, or for a similarly constructed device such as a pump...
to the exhaust manifold.
American Motor introduced an aluminum block version of the OHV engine in 1961. It was produced through 1964. This engine used
cast ironCast iron usually refers to grey iron, but also identifies a large group of ferrous alloys, which solidify with a eutectic. The colour of a fractured surface can be used to identify an alloy. White cast iron is named after its white surface when fractured, due to its carbide impurities which...
cylinder liners and a cast iron head. The head is slightly wider on the right side than the cast iron block head. The heads will physically interchange, but the head designed for the cast iron block will need material added to its right side to properly seal on an aluminum block.
The 196 OHV requires more periodic maintenance than newer model engines. The head bolts must be re-torqued (retightening process) regularly. Factory service manuals recommend that head bolt torque be checked every and to re-torque them every . With modern head gaskets this service interval can be extended to re-torque the bolts every miles, or every other year. The exact cause of the headbolts loosening over time is unknown, but it is believed that thermal expansion and contraction of the block, head, and bolts eventually causes the seal between the head and block to loosen. This maintenance is imperative to prevent the engine from running hot (the first sign of a blown head gasket) and thus warping or cracking the head. The cast iron liners in the aluminum block version can also shift if the head bolts are not properly torqued and the engine is run hot. If this process is not followed, then repairs will be necessary and replacement heads and aluminum blocks for these engines are now more difficult to find.
In compensation, this required maintenance is quite easy. Re-torquing the head and adjusting the valves typically takes under 45 minutes to complete, start to finish, and is done with only two open-end wrenches and a feeler gauge. Some skills are required, but it is not challenging, and adjusting the valves on a running engine (as is required) is today a rare pleasure.
Modern head gaskets usually come with a statement that "no re-torque or sealant is required". This "no re-torque" refers to the process when the early gaskets had to be retightened upon installation after the engine had been run for a short period at full operating temperature. This procedure was necessitated by the type of material used for the gaskets. This process was usually called "bedding in" the gasket. Today, all replacement 196 head gaskets are made of modern materials and do not need to be retightened after the initial installation. However, they still require re-torquing every 8,000-12,000 miles or every other year as noted previously.
It is imperative to use a sealant on all 196 head gaskets. Long-term experience of owners of cars with the 196 engine is that the gaskets need an additional sealant regardless of the gasket manufacturers recommendation. A brush-on
shellacShellac is a resin secreted by the female lac bug to form a cocoon, on trees in the forests of India and Thailand. It is processed and sold as dry flakes , which are dissolved in denatured alcohol to make liquid shellac, which is used as a brush-on colorant, food glaze and wood finish much like a...
(such as "Indian Head" brand) or spray-on copper or aluminum sealer is all that is needed. Without the additional sealer the head gasket will seep a small amount oil into the water jacket and down the sides of the engine. Nevertheless, there seems to be a small amount of seepage on the right side even with sealer that is normal for this engine. This is likely due to the number of head bolts (15 - four around each cylinder plus one extra) and just adequate sealing surfaces - at least wide in all areas, but not much more in most. On the L-head engines, the head also seals the intake tract on the right side of the engine.
The modern era I-6
The company designed an entirely new six cylinder for 1964, and was produced, albeit in a modified form, up until 2006.
First produced in 1964 and introduced as an option in the Classic and Ambassador in the middle of the 1964 model year, the "Typhoon" in-line six was AMC's first modern six cylinder engine. It replaced the
NashAlso see: Kelvinator and American Motors CorporationNash Motors was an automobile manufacturer based in Kenosha, Wisconsin, in the United States from 1916 to 1938. From 1938 to 1954, Nash was the automotive division of the Nash-Kelvinator Corporation...
OHV I-6 in the Classic and Ambassador in 1965 (the first use of a six in the Ambassador since 1956). In 1966 a version finally replaced the aging OHV and L-head engines. To commemorate the engine's May 1964 introduction, 2,520 "Typhoon" cars were made on the Classic hardtop body. Each featured the new 232 six, Solar Yellow body paint, a Classic Black roof, and a distinctive "Typhoon" script in place of the usual "Classic" name. All other AMC options (except engine options) were available.
Both the 199 and 232 featured a bore, and either a or stroke. The 199 was discontinued in 1970; the 232 was offered alongside the (made by using a stroke crankshaft and slightly taller block) during the 1970s, but was discontinued in 1979. Increasing emissions controls continued to rob the engine of power, making the smaller version inadequate as safety regulations also added weight to the vehicles it was required to push around.
AMC changed the deck height of the six in 1971, increasing it 1/8-inch to allow the longer stroke of the 258. This alters pushrod length on all engines built after 1971. The 232 was continued on the taller deck block by using the previous crankshaft with the slightly longer 199 rod.
199
The 199 cubic inch/3.3L (198.8cuin / 3,258cc)
199 was produced from 1965 through 1970.
Applications:
- Rambler Classic
The Rambler Classic was an intermediate sized automobile that was built and sold by American Motors Corporation from 1961 to 1966. The Classic took the place of the Rambler Six and Rambler Rebel V-8 names, which were retired at the end of the 1960 model year.Introduced in six-passenger four-door...
(1965-66, fleet cars only)
- Rambler American/AMC Rambler
The Rambler American was an automobile manufactured by the American Motors Corporation between 1958 and 1969. The American was the second incarnation of AMC's forerunner Nash Motors second generation Rambler compact that was sold under the Nash and Hudson Motors marques from 1954 and 1955.The...
(1965-69)
- AMC Hornet
The AMC Hornet was a compact automobile made by the American Motors Corporation beginning with the 1970 model year and continuing through the 1977 model year. The Hornet replaced the compact Rambler American marking the end of the Rambler marque in the American and Canadian markets.The new Hornet...
(1970)
- AMC Gremlin
The AMC Gremlin is a subcompact car that was made by the American Motors Corporation for nine model years. Compared to its competition, The Gremlin reduced development and manufacturing costs by adapting the distinctive abbreviated tail to the compact Hornet, producing what was described at its...
(1970)
232
The 232 cubic inch/3.8L (231.9cuin / 3,801cc)
232 was produced from 1964 through 1979. Through 1970, the engine shared a deck height with the 199. Starting in 1971 AMC raised the deck height to produce the 258, and the 232 adopted the 199's longer connecting rods. Bore and stroke remained the same.
Applications:
- Rambler Classic
The Rambler Classic was an intermediate sized automobile that was built and sold by American Motors Corporation from 1961 to 1966. The Classic took the place of the Rambler Six and Rambler Rebel V-8 names, which were retired at the end of the 1960 model year.Introduced in six-passenger four-door...
(1964-1966)
- Rambler American/AMC Rambler
The Rambler American was an automobile manufactured by the American Motors Corporation between 1958 and 1969. The American was the second incarnation of AMC's forerunner Nash Motors second generation Rambler compact that was sold under the Nash and Hudson Motors marques from 1954 and 1955.The...
(1964-1969)
- Rambler/AMC Marlin (1965-1967)
- Rambler/AMC Ambassador
The Ambassador was the top-line automobile produced by the American Motors Corporation from 1958 until 1974. The vehicle was known as the AMC Ambassador, Ambassador V-8 by Rambler, and Rambler Ambassador at various times during its tenure in production. Previously, the name Ambassador had applied...
(1965-1970)
- Rambler/AMC Rebel
}The AMC Rebel is a mid-size car produced by American Motors Corporation from 1967 to 1970. It replaced the Rambler Classic...
(1967-70)
- AMC Javelin
The AMC Javelin was a “pony car” built by the American Motors Corporation between 1968 and 1974.Its production can be classified into two generations: 1968 to 1970 and 1971 to 1974...
(1968-74)
- AMC Hornet
The AMC Hornet was a compact automobile made by the American Motors Corporation beginning with the 1970 model year and continuing through the 1977 model year. The Hornet replaced the compact Rambler American marking the end of the Rambler marque in the American and Canadian markets.The new Hornet...
(1970-77)
- AMC Gremlin
The AMC Gremlin is a subcompact car that was made by the American Motors Corporation for nine model years. Compared to its competition, The Gremlin reduced development and manufacturing costs by adapting the distinctive abbreviated tail to the compact Hornet, producing what was described at its...
(1970-78)
- AMC Matador
The AMC Matador is an intermediate car that was built and sold by American Motors Corporation from 1971 to 1978. These models were also assembled in Mexico by Vehículos Automotores Mexicanos and in Australia by Australian Motor Industries with modifications for their markets including continuing...
(1971-74)
- AMC Pacer
The AMC Pacer is a two-door compact automobile produced in the United States by the American Motors Corporation between 1975 and 1980. Its initial design idea was started in 1971. The car's unusual rounded shape with massive glass area greatly contrasted with the mostly boxy, slab-sided models of...
(1975-79)
- AMC Concord
The AMC Concord was a compact car made by the American Motors Corporation starting with Model year 1978 and continuing to 1983. The Concord was intended to replace not only the similar AMC Hornet, but to some extent the aging mid-size AMC Matador that would be discontinued after 1978 in a market...
(1978-79)
- AMC Spirit
The AMC Spirit was a subcompact marketed by American Motors Corporation from 1979 to 1983 as a restyled replacement for the AMC Gremlin. The Spirit shared the Gremlin's platform and was offered in two hatchback variations, each with two doors — marketed as sedan and liftback...
(1979)
- Jeep CJ
The Jeep CJ is a public version of the famous Military Jeep from World War II.The first CJ prototype was introduced in 1944 by Willys, and the same basic vehicle stayed in production through seven variants and three corporate parents until 1986.A variant of the CJ is still in production today...
(1972-79)
- Jeep Cherokee
Jeep Cherokee may refer to:* Jeep Cherokee * Jeep Cherokee * Jeep Grand Cherokee , , and * Jeep Liberty, a.k.a. Jeep Cherokee...
(1974-79)
- Jeep Wagoneer
The Jeep Wagoneer was an early sport utility vehicle , produced under varying marques from 1963 to 1991. It was noteworthy for being in production for more than 28 years with only minor mechanical changes...
(1965-1971)
- Jeep J series trucks
Jeep's SJ platform was part of the "FSJ" or full-size Jeep lineup. According to the , an "FSJ" is any vehicle produced in North America, carrying the "Jeep" nameplate, with 2 or 4 doors, in rear or four wheel drive, whose wheelbase does not exceed 132 in, nor is less than 109 in, and whose tread...
(1965-1970)
- Jeep Commando (1972-1973)
- International Harvester Scout
The International Harvester Scout was one of the first production American civilian off-road sport utility vehicles. It was originally created as a competitor to the Jeep, and like that vehicle, early models featured fold-down windshields...
(1969-1971)
252
The engine was produced by AMC's Mexican subsidiary
Vehiculos Automotores MexicanosVehiculos Automotores Mexicanos S.A. was an automaker in Mexico. The original organization, a distributor for Willys-Overland vehicles, became government controlled in 1963 with American Motors Corporation holding a minority interest. The company imported and produced automobiles and light...
(VAM) beginning in late 1971 or early 1972. This was similar to a 232 in stroke with a larger bore (252.15 cuin / 4,130 cc).
Output for 1972 Rally model:
- Horsepower 170 @ 4600 rpm
- Torque 240 @ 2300
Engine dimensions:
- CR (standard model was 8.5:1)
- Intake Valve Diameter
- Exhaust Valve Diameter
- Pushrod Length
- Deck Height
- Bore
- Stroke
Applications:
- VAM Pacer AMC Pacer
The AMC Pacer is a two-door compact automobile produced in the United States by the American Motors Corporation between 1975 and 1980. Its initial design idea was started in 1971. The car's unusual rounded shape with massive glass area greatly contrasted with the mostly boxy, slab-sided models of...
- VAM Rally AMX and Rally GT Spirit
The AMC Spirit was a subcompact marketed by American Motors Corporation from 1979 to 1983 as a restyled replacement for the AMC Gremlin. The Spirit shared the Gremlin's platform and was offered in two hatchback variations, each with two doors — marketed as sedan and liftback...
- VAM American and American Rally AMC Hornet
The AMC Hornet was a compact automobile made by the American Motors Corporation beginning with the 1970 model year and continuing through the 1977 model year. The Hornet replaced the compact Rambler American marking the end of the Rambler marque in the American and Canadian markets.The new Hornet...
and AMC ConcordThe AMC Concord was a compact car made by the American Motors Corporation starting with Model year 1978 and continuing to 1983. The Concord was intended to replace not only the similar AMC Hornet, but to some extent the aging mid-size AMC Matador that would be discontinued after 1978 in a market...
- VAM Gremlin AMC Gremlin
The AMC Gremlin is a subcompact car that was made by the American Motors Corporation for nine model years. Compared to its competition, The Gremlin reduced development and manufacturing costs by adapting the distinctive abbreviated tail to the compact Hornet, producing what was described at its...
- VAM Classic AMX and Brougham AMC Matador
The AMC Matador is an intermediate car that was built and sold by American Motors Corporation from 1971 to 1978. These models were also assembled in Mexico by Vehículos Automotores Mexicanos and in Australia by Australian Motor Industries with modifications for their markets including continuing...
Coupe
- VAM Classic AMC Matador
The AMC Matador is an intermediate car that was built and sold by American Motors Corporation from 1971 to 1978. These models were also assembled in Mexico by Vehículos Automotores Mexicanos and in Australia by Australian Motor Industries with modifications for their markets including continuing...
- VAM Javelin AMC Javelin
The AMC Javelin was a “pony car” built by the American Motors Corporation between 1968 and 1974.Its production can be classified into two generations: 1968 to 1970 and 1971 to 1974...
- VAM Lerma
The VAM Lerma was an automobile designed and manufactured by Vehiculos Automotores Mexicanos in the early 1980s. The car was based on two other vehicles by VAM's license partner American Motors ....
258
The in-line six was produced from 1971 until 1990. It featured an undersquare bore and stroke; it was otherwise similar to the 199 and 232. Later 258 models (starting with the 1980 model year for
CaliforniaCalifornia is the most populous state in the United States, and the third largest by area. California is the second most populous sub-national entity in the Americas, behind only São Paulo, Brazil...
AMCs, 1981 for California Jeeps and 1982 for all other applications) are equipped with AMC's
CECThe Computerized Engine Control or CEC system was an engine management system designed and used by American Motors and Jeep from 1980-1990, on the AMC 258 engine....
system.
Applications:
- AMC Hornet/Concord
The AMC Hornet was a compact automobile made by the American Motors Corporation beginning with the 1970 model year and continuing through the 1977 model year. The Hornet replaced the compact Rambler American marking the end of the Rambler marque in the American and Canadian markets.The new Hornet...
/SpiritThe AMC Spirit was a subcompact marketed by American Motors Corporation from 1979 to 1983 as a restyled replacement for the AMC Gremlin. The Spirit shared the Gremlin's platform and was offered in two hatchback variations, each with two doors — marketed as sedan and liftback...
/EagleThe AMC Eagle was an all-wheel drive passenger car produced by American Motors Corporation . Introduced in August 1979 , the coupe, sedan, and wagon were based on the AMC Concord. AMC Spirit-based models joined the line in 1981...
(1971–1988)
- AMC AMC Pacer
The AMC Pacer is a two-door compact automobile produced in the United States by the American Motors Corporation between 1975 and 1980. Its initial design idea was started in 1971. The car's unusual rounded shape with massive glass area greatly contrasted with the mostly boxy, slab-sided models of...
- AMC AMC Matador
The AMC Matador is an intermediate car that was built and sold by American Motors Corporation from 1971 to 1978. These models were also assembled in Mexico by Vehículos Automotores Mexicanos and in Australia by Australian Motor Industries with modifications for their markets including continuing...
(1971–1978)
- AMC Gremlin
The AMC Gremlin is a subcompact car that was made by the American Motors Corporation for nine model years. Compared to its competition, The Gremlin reduced development and manufacturing costs by adapting the distinctive abbreviated tail to the compact Hornet, producing what was described at its...
and SpiritThe AMC Spirit was a subcompact marketed by American Motors Corporation from 1979 to 1983 as a restyled replacement for the AMC Gremlin. The Spirit shared the Gremlin's platform and was offered in two hatchback variations, each with two doors — marketed as sedan and liftback...
(1971–1983)
- International Harvester Scout
The International Harvester Scout was one of the first production American civilian off-road sport utility vehicles. It was originally created as a competitor to the Jeep, and like that vehicle, early models featured fold-down windshields...
& Light Duty trucks (1972-1974)
- Jeep CJ
The Jeep CJ is a public version of the famous Military Jeep from World War II.The first CJ prototype was introduced in 1944 by Willys, and the same basic vehicle stayed in production through seven variants and three corporate parents until 1986.A variant of the CJ is still in production today...
(1972–1986)
- Jeep Cherokee
Jeep Cherokee may refer to:* Jeep Cherokee * Jeep Cherokee * Jeep Grand Cherokee , , and * Jeep Liberty, a.k.a. Jeep Cherokee...
and WagoneerThe Jeep Wagoneer was an early sport utility vehicle , produced under varying marques from 1963 to 1991. It was noteworthy for being in production for more than 28 years with only minor mechanical changes...
(1972–1986)
- Jeep J series trucks
Jeep's SJ platform was part of the "FSJ" or full-size Jeep lineup. According to the , an "FSJ" is any vehicle produced in North America, carrying the "Jeep" nameplate, with 2 or 4 doors, in rear or four wheel drive, whose wheelbase does not exceed 132 in, nor is less than 109 in, and whose tread...
(1971-1988)
- Jeep Wrangler
The Wrangler is a compact four-wheel drive in the sport utility vehicle segment produced by American automaker Chrysler under its Jeep marque. It is a successor to the famous World War II 'Jeep' vehicle by way of the Willys civilian Jeep in the 1950s, later produced by Kaiser-Jeep and by American...
(1987–1990)
- Jeep Commando (1972-1973)
282
The engine was produced by AMC's Mexican subsidiary
Vehiculos Automotores MexicanosVehiculos Automotores Mexicanos S.A. was an automaker in Mexico. The original organization, a distributor for Willys-Overland vehicles, became government controlled in 1963 with American Motors Corporation holding a minority interest. The company imported and produced automobiles and light...
(VAM) beginning in late 1971 or early 1972. This was similar to a 258 in stroke with a larger bore (281.7cuin / 4,616cc).
Output for 1977 models:
- Horsepower 200 @ 4400
- Torque 280 @ 2200
- CR
Output for 1979 Standard models:
- Horsepower 132 @ 3800
- Torque 216 @ 2200
- CR
Output for 1979 S and GT models:
- Horsepower 172 @ 4200
- Torque 225 @ 2600
- CR
Output for 1982-83 models:
- Horsepower 129 @ 4000
- Torque 218 @ 1800
- CR
Engine dimensions:
- Intake Valve Diameter
- Exhaust Valve Diameter
- Pushrod Length
- Deck Height
- Bore
- Stroke
Applications:
- VAM Pacer AMC Pacer
The AMC Pacer is a two-door compact automobile produced in the United States by the American Motors Corporation between 1975 and 1980. Its initial design idea was started in 1971. The car's unusual rounded shape with massive glass area greatly contrasted with the mostly boxy, slab-sided models of...
- VAM Rally AMX and Rally GT Spirit
The AMC Spirit was a subcompact marketed by American Motors Corporation from 1979 to 1983 as a restyled replacement for the AMC Gremlin. The Spirit shared the Gremlin's platform and was offered in two hatchback variations, each with two doors — marketed as sedan and liftback...
- VAM American and American Rally AMC Hornet
The AMC Hornet was a compact automobile made by the American Motors Corporation beginning with the 1970 model year and continuing through the 1977 model year. The Hornet replaced the compact Rambler American marking the end of the Rambler marque in the American and Canadian markets.The new Hornet...
and AMC ConcordThe AMC Concord was a compact car made by the American Motors Corporation starting with Model year 1978 and continuing to 1983. The Concord was intended to replace not only the similar AMC Hornet, but to some extent the aging mid-size AMC Matador that would be discontinued after 1978 in a market...
- VAM Gremlin AMC Gremlin
The AMC Gremlin is a subcompact car that was made by the American Motors Corporation for nine model years. Compared to its competition, The Gremlin reduced development and manufacturing costs by adapting the distinctive abbreviated tail to the compact Hornet, producing what was described at its...
- VAM Classic AMX and Brougham AMC Matador
The AMC Matador is an intermediate car that was built and sold by American Motors Corporation from 1971 to 1978. These models were also assembled in Mexico by Vehículos Automotores Mexicanos and in Australia by Australian Motor Industries with modifications for their markets including continuing...
Coupe
- VAM Classic AMC Matador
The AMC Matador is an intermediate car that was built and sold by American Motors Corporation from 1971 to 1978. These models were also assembled in Mexico by Vehículos Automotores Mexicanos and in Australia by Australian Motor Industries with modifications for their markets including continuing...
- VAM Javelin AMC Javelin
The AMC Javelin was a “pony car” built by the American Motors Corporation between 1968 and 1974.Its production can be classified into two generations: 1968 to 1970 and 1971 to 1974...
- VAM Lerma
The VAM Lerma was an automobile designed and manufactured by Vehiculos Automotores Mexicanos in the early 1980s. The car was based on two other vehicles by VAM's license partner American Motors ....
4.0
The 242 cubic inch "242
or 4.0 L
or 4.0"
straight-6The straight-six engine or inline-six engine is a six cylinder internal combustion engine with all six cylinders mounted in a straight line along the crankcase. The single bank of cylinders may be oriented in either a vertical or an inclined plane with all the pistons driving a common crankshaft...
, that was introduced in 1987, was an evolution of the 258 I-6 and the 150/2.5 L,
AMC's straight-4The American Motors Corporation straight-4 engine was used by a number of AMC, Jeep, and Dodge vehicles from 1984 through 2002.* For an outline of all engines used by AMC see -Development:...
. It had the same bore as the 2.5 with a longer stroke giving it a displacement of 241.6
CIDA cubic inch is a non-SI unit of volume, equal to the volume of a cube with sides of one inch.Cubic inches are still sometimes used as a unit of measurement in the United States and Canada, although SI is continuing to gradually displace non-SI usage.-Notation conventions:The following symbols...
(3,959 cc).
This American Motors Corporation legacy engine was redesigned by Chrysler to reduce
noise, vibration, and harshnessNoise, vibration, and harshness , also known as noise and vibration , is the study and modification of the noise and vibration characteristics of vehicles, particularly cars and trucks...
. The last in the line of the seven main bearing AMC inline sixes, the 4.0 is regarded as one of the best 4x4 off-road engines. The 4.0 AMC six has many after market parts due to its longevity and durability. Many of these engines are known to go more than 300,000 miles (483,000 km) without rebuilding.
The first 4.0 engines in 1987 had
RENIXRenix made automobile electronic ignitions, fuel-injection systems, electronic automatic transmission controls, and various engine sensors.The term Renix also has a number of applications...
(
RenaultRenault S.A. is a French automaker producing cars, vans, buses, tractors, and trucks. Due to its alliance with Nissan, it is currently the world's fourth largest automaker. Headquartered in Boulogne-Billancourt, Renault owns the Romanian automaker Automobile Dacia and the Korean automaker Renault...
/
BendixBendix may refer to:* John E. Bendix, American Civil War and New York Guard general* Vincent Bendix** The Bendix Corporation** Bendix Helicopters** The Bendix trophy* Reinhard Bendix - sociologist* William Bendix* Knuth-Bendix completion algorithm...
) engine control systems, which were quite advanced for their time, but are now handicapped because there are very few scan tools which can be "plugged in" to a RENIX system for diagnosis. The RENIX also used a
engine knockingKnocking in spark-ignition internal combustion engines occurs when combustion of the air/fuel mixture in the cylinder starts off correctly in response to ignition by the spark plug, but one or more pockets of air/fuel mixture explode outside the envelope of the normal combustion front...
sensor, which allowed the computer to know if pre-detonation was occurring, thus allowing the computer to make the appropriate changes to prevent this. RENIX systems have no "permanent" memory for the diagnostics system. Once the ignition switch is turned off any codes generated are lost, thus making it difficult to detect intermittent problems.
The 1987 RENIX 4.0 made and of torque. In 1988 the 4.0 received higher flowing fuel injectors, raising output to and . In comparison, "this engine made more power than the
Ford 302 V8The Windsor engine is a 90-degree small-block V8 from Ford Motor Company. It was introduced in 1962, replacing the old Ford Y-block engine. Though not all of the engines in this family were produced at the Windsor, Ontario engine plant , the name stuck...
,
Chevy 305 V8The Chevrolet small-block engine is a series of automobile V8 engines built by the Chevrolet Division of General Motors using the same basic small engine block...
,
Chrysler 318 V8The LA engines are a family of pushrod OHV 90° V-block gasoline engines built by Chrysler Corporation and factory-installed in passenger vehicles, trucks and vans, commercial vehicles, marine and industrial applications from 1964 through 2003...
, as well as any of the 6 cylinder engines the Japanese were putting in their trucks... and it had comparable or better fuel economy."
Chrysler bought AMC in 1987 and continued to produce the 4.0 straight six. In 1991 Chrysler redesigned the RENIX engine control computer and raised the intake ports approximately 1/8-inch (3.175 mm) for a better entry radius. Chrysler also enlarged the throttle body and redesigned the intake and exhaust manifolds for more efficiency, and the fuel injectors were once again replaced with higher flowing units. The camshaft profile was also changed. The net result was an engine that made and of torque. Badging on most Jeeps equipped with this engine read "4.0 Litre HIGH OUTPUT." The new cam profile combined with altered computer programming eliminated the need for an EGR valve and knock sensor, but made the engine more sensitive to alterations, especially where emissions are concerned.
Small changes were made to the cylinder head for the 1995 model year. In 1996, the engine block was redesigned, and a new strengthened unit was then used. The new block made use of more webbing cast into the block, and a stud girdle for added rigidity of the crankshaft main bearings. The cylinder head was again changed around 1998 to a lower flowing, more emissions-friendly design. Engines installed in 1999 Grand Cherokees carried the
Power Tech name, which had been used intermittently in prior years. The name was subsequently passed on to 4.0s in all Jeep models.
Output as of 2004 was at 4600 rpm with of torque at 3000 rpm.
The 4.0 is probably the most recognizable and longest-running Jeep powerplant in the brand's history. It was discontinued at the end of the 2006 model year as the redesigned 2007 and onward the JK
Jeep WranglerThe Wrangler is a compact four-wheel drive in the sport utility vehicle segment produced by American automaker Chrysler under its Jeep marque. It is a successor to the famous World War II 'Jeep' vehicle by way of the Willys civilian Jeep in the 1950s, later produced by Kaiser-Jeep and by American...
s use Chrysler's 3.8 L OHV V6. However, it is foreseeable that this engine may be made for many more years in the
People's Republic of ChinaThe People's Republic of China , commonly known as China, is the largest country in East Asia and the most populous in the world with over 1.3 billion people, approximately one-fifth of the world's population...
, where a slightly modified version of the XJ Jeep Cherokee with 2.5 and 4.0 engines are still being produced alongside the Chinese-produced WJ Grand Cherokee, produced in China since 2006. There is still a large amount of aftermarket vendors for the engine as it has a large following in the off-road community.
This engine was used in the following vehicles:
- 1987–2001 Jeep Cherokee
Jeep Cherokee may refer to:* Jeep Cherokee * Jeep Cherokee * Jeep Grand Cherokee , , and * Jeep Liberty, a.k.a. Jeep Cherokee...
- 1993–2004 Jeep Grand Cherokee
The Jeep Grand Cherokee is a mid-size UniFrame sport utility vehicle produced by the Jeep division of Chrysler. European Grand Cherokees are manufactured in Austria by Magna Steyr.- Development :...
- 1987–1990 Jeep Wagoneer
The Jeep Wagoneer was an early sport utility vehicle , produced under varying marques from 1963 to 1991. It was noteworthy for being in production for more than 28 years with only minor mechanical changes...
- 1987–1992 Jeep Comanche
thumb|right|Jeep ComancheThe Jeep Comanche is a pickup truck version of the Cherokee compact SUV that was produced from 1986 to 1992...
- 1991–2006 Jeep Wrangler
The Wrangler is a compact four-wheel drive in the sport utility vehicle segment produced by American automaker Chrysler under its Jeep marque. It is a successor to the famous World War II 'Jeep' vehicle by way of the Willys civilian Jeep in the 1950s, later produced by Kaiser-Jeep and by American...
Rod Lengths
1964-71:
- 199 CID
A cubic inch is a non-SI unit of volume, equal to the volume of a cube with sides of one inch.Cubic inches are still sometimes used as a unit of measurement in the United States and Canada, although SI is continuing to gradually displace non-SI usage.-Notation conventions:The following symbols...
(3.3 L) -
- 232 CID (3.8 L) -
1972-2006:
- 232 CID (3.8 L) -
- 242 CID (4.0 L) -
- 258 CID (4.2 L) -
- The cubic in displacement is different from the 1990-95 and 1996-2006 I6 by 2 ci. From 90 through 95 the bore was 3.88 in and stroke of 3.44. In 1996 the bore was the same but the stroke changed to 3.41 in. Mathematically it comes out to the true 242 ci for 1996-2006 but the 1990-95 are 244ci. Both equal to 4.0 liters though (most likely due to varying methods of rounding numbers)*
See also
- AMC Straight-4 engine
The American Motors Corporation straight-4 engine was used by a number of AMC, Jeep, and Dodge vehicles from 1984 through 2002.* For an outline of all engines used by AMC see -Development:...
- AMC V8 engine
American Motors Corporation produced a series of widely-used V8 engines from the mid-1950s before being absorbed into Chrysler in 1987. Chrysler kept the AMC V8 in production until 1991 for the Jeep Grand Wagoneer....
- AMC Engines
The American Motors Corporation used V8, straight-6, V6, and straight-4 engines in various passenger automobiles and Jeep vehicles from 1964 through 2006. Some engines were of AMC design or inherited from its constituents...
- AMC and Jeep transmissions
Vehicles made by American Motors Corporation and Jeep have used a variety of transmissions and transfer case systems throughout the years in which they have been produced...
- List of Chrysler engines
- Allpar's 4.0 page