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Ultimate Mopar Engines

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  • One of the most famous engines of all time is the original Chrysler Hemi, which debuted in 1951. - 1
  • Succeeding the original Hemi as Chrysler’s mainstream performance engine was the B-series 413/426 Wedge. - 2
  • One of the most popular and enduring small-block Chrysler V-8s was the LA. - 3
  • Extremely robust, the B-series was conceived as a low-cost, big-inch passenger car engine, though it proved its worth in light and medium-duty trucks. - 4
  • Few engines are more recognized than the formidable 426 Hemi. - 5
  • A high performance derivative of the 273/318, the 340 is considered one of the best small block performance V-8s ever built. - 6
  • Big cubes and lots of lazy, low-end torque made the RB 383 a very popular street engine for much of the 1960s. - 7
  • An outgrowth of the 383, the 440 was Chrysler’s mainstream high-performance big- block from the mid-1960s through the early 1970s. - 8
  • The ultimate version of the 440 was the Six-Pack, which featured a special Edelbrock-designed intake manifold on which sat a trio of Holley carburetors. - 9
  • Originally conceived for use in the Dodge Challenger T/A and Plymouth AAR ’Cuda Trans Am homologation specials, the LA 340 also found a home in the Duster and Demon. - 10
  • One of the last surviving Chrysler big-block V-8s was the 400, based on the original B-series 383. - 11
  • Based on the LA small block V-8, the Chrysler V-10 (first seen in 1992) was originally conceived as a truck engine, though is best known for powering the Dodge Viper. - 12
  • Chrysler introduced a new 345 cubic inch (5.7-liter) “Hemi” as a regular production engine in 2003. - 13
  • A larger, more high-performance version of the new Hemi V-8 was introduced for 2006. - 14
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by Huw Evans  More from Author

Highlighting Chrysler’s Greatest Postwar Powerplants

Out of Detroit’s “big three” automakers, Chrysler was the only one that truly went for broke during the postwar period when it came to factory performance, both on the street and the race track. Dishing up cars like the Plymouth 426 Wedge, Hemi ’Cuda and Dodge Charger, Challenger and Super Bee 440 Six Pack, it cemented a fearsome performance reputation that stands to this very day. And much like the cars they powered, the classic post war Mopar V-8s have become the stuff of legend. Some of them endured for decades, coping with all kinds of obstacles, including fuel economy and emissions standards, as well as continuing to set records in motorsport. Even today, Hemis are still the preferred choice for top-level drag racing. Thanks to the incredible Viper V-10 and a new generation of Hemi V-8s, Chrysler is once again back in the high performance game. Recognizing the significant impact of Chrysler engines on the performance landscape, we decided to put together a list of some of the most incredible motors to ever be installed between the fenders of a car – period.


Chrysler Firepower/Desoto Firedome/Dodge Red Ram

Although the first Hemi head V-8 wasn’t introduced to Chrysler passenger cars until 1951, development on a new, lightweight and compact overhead valve engine to replace the existing L-head six and straight eights began in the early 1940s, just as US involvement in World War II was ramping up. At the time, engineers were discovering that carbon deposits in the combustion chamber were becoming a big problem. It was, in fact, so much that some existing engine designs were losing as much as 20 percent of power after just 10,000 miles of use. Taking a page out of the racing book, Chrysler engineers, led by William Drinkard, altered the shape of the combustion chamber to create a hemispherical design and placed the intake valves close to the engine manifold and carburetor, at 58 degrees across the top of the chamber. This made it possible to dramatically increase volumetric efficiency and power while improving reliability  (reducing carbon build up and extending valve life, as well as reducing the risk of detonation). One of the most interesting early experiments involving such a Chrysler “Hemi head” engine was a massive, inverted, liquid-cooled V-16, fitted to a Republic P-47 Thunderbolt fighter aircraft. Although this version never saw production, the massive V-16 delivered tremendous power and enabled the XP-47 to achieve a record 500 mph in level flight on more than one occasion.

Development on this new lightweight V-8 continued once hostilities had ceased. Built around the concept of a 90-degree unit, sized around 330 cubic inches and capable of lasting 100,000 miles, Drinkard’s proposal was finally given the green light by Chrysler’s then-CEO, K.T. Keller, in 1948. Early teething problems centering around camshaft wear were overcome, and the production Hemi V-8 – dubbed Firepower – was ready for installation in the 1951 Chrysler Saratoga, New Yorker and Imperial. Featuring a 3.81-inch bore and 3.63-inch stroke, it was sized at 331 cubic inches and employed “slipper” pistons to reduce friction and extend engine life. It was a very advanced design by the standards of the day. With 180 hp and 312 lb-ft of torque, it was also a stellar performer (a 1951 Saratoga was clocked running to 60 mph in 12 seconds flat, beating the hallowed Cadillac Series 62 and Oldsmobile Rocket 88). Enlarged to 354 cubic inches in 1955 for the 1956 model year and then 392 in 1957, the original Hemi also became progressively more powerful (making up to 375-390 hp) and became a mainstay among Chrysler passenger cars through 1958. It also proved to be very popular with hot rodders, particularly in sanctioned drag racing, where supercharged Hemis ruled the strip in the A and B/Gas classes for much of the 1960s.

Besides Chrysler division, DeSoto and Dodge also had their own versions of Hemi called the Firedome and Red Ram, respectively. The DeSoto version, introduced first in 276-ci form, featured a 3.62 inch bore and 3.34 inch stroke and was rated at 160 hp. This engine was increased in size to 291 cubic inches for 1955, by which time it was making 185-200 hp on a 7.9:1 compression ratio. It was further enlarged to 330 and then 345 cubic inches and fitted to the top line Adventurer two-door hardtop and convertible, where it was rated at 320 hp, almost matching the formidable Hemi Chrysler 300 for all-out performance.

The Dodge version was the smallest of the lot, initially a 241 cubic inch unit, with 3.31 bore and 3.25-inch stroke and rated at 140 hp. Unlike the Chrysler and DeSoto versions, it featured a simpler valvetrain setup, with single instead of dual rockers per cylinder, and heads with slightly more rounded  “Polyspherical” shaped combustion chambers that were cheaper to produce. By 1956, it had been enlarged to 315 cubic inches via a 3.63-inch bore and 3.60-inch stroke and in base trim, was rated at 218 hp. Two more powerful versions, with 230 (Super Red Ram) and 260 hp (D-500) were also offered, along with an over the counter four-barrel carburetor setup that was reportedly good for another 30 horses. Even larger 325-ci versions followed for 1957, with 245 hp, 285 and a stomping 310 horsepower in D-500 form. Although the Dodge and DeSoto versions are overshadowed by the original Chrysler Hemi today, they were both well received when new, and, in Dodge’s case, paved the way for a high performance image still enjoyed by the company today.


413/426 ‘Wedge’ V-8

For 1959, Chrysler replaced its Hemi with the B-series big-block V-8, first seen the previous year. The B-series, unlike the Hemi, featured wedge-type combustion chambers and a single rocker per valve. Initially offered in 350- and 361-ci versions, and then, for 1959, 383- and 413-ci forms, it was less temperamental and complex than the Hemi, as well as being much cheaper to build. It also had the ability to be stroked considerably and would lead to a whole raft of future engines, some of which would endure for another three decades.

One of the most intriguing of the early B-series motors was the 413/426 Wedge, which became Chrysler’s high performance standard-bearer during the early 1960s. The company had been experimenting with some wild cross-ram intake setups, and for 1960 introduced the option on the 383 B-series V-8. Using dual carburetors, each suspended on a very long intake runner on opposite sides of the engine that fed the air/fuel mixture from them to the intake manifold center, the design promoted a greater torque spread. This enabled quick passing and acceleration, making these cars among the fastest and most tractable on the street at the time. The 413, which featured a 4.18-inch bore and 3.75-inch stroke, came equipped with a stronger block with a raised deck height (called the “RB” for “raised block”), was seen as the perfect foundation for a high performance racing engine. Why not combine it with a short cross ram setup to improve high rpm horsepower? The result was the 413 Max Wedge, first seen in 1962 and dubbed the Ramcharger by Dodge and Super Stock by Plymouth. The dual four-barrel Carter carburetors were mounted inside of the rocker covers this time, but special heads were fitted. These featured enormous 2.08-inch intake valves, extra strong cam followers, guides, rocker arms and solid valve lifters.  A specific high-lift camshaft, high flow oil pump and magnafluxed connecting rods were also specified in the interests of extreme performance and durability. There were also special, cast iron exhaust manifolds that swept upwards (it was the only way to provide adequate engine bay clearance in the downsized 1962 Plymouth.

Installed in a Savoy or Dodge Dart light weight two-door, the 413 Wedge was capable of propelling these cars to 12 second ETs. Tom Grove drove a Max Wedge Plymouth to a record 11.93-second elapsed time in July of that year. By December, Max Wedge powered cars had set four NHRA class records, effectively ending Chevrolet’s domination of the NHRA stock ranks. For 1963, Chrysler gave this engine a larger 4.25-inch bore, resulting in the 426 cubic inch Stage II. This featured a beefed-up valvetrain and new pistons, raising compression to a towering 11.0:1. Rated at 415 hp, or 425 hp on an even tighter 13.5:1 squeeze, the Stage II Wedge was a serious force to be reckoned with both in sanctioned drag racing and on the NASCAR circuit. Al “The Lawman” Eckstrand won that year’s Top Stock class at the NHRA Winternationals behind the wheel of his 1963 Dodge Ramcharger.

It’s interesting to note that although Dodge and Plymouth both recommended using the 426 Wedge engine only for “supervised driving competition,” this highly strung engine was available in nearly every model and trim level. For 1964, an even hotter Stage III version was released, with new cylinder heads designed to promote even faster burning, along with a new camshaft and valvetrain pieces. However, the Wedge’s days as the primary competition engine were coming to close as Chrysler trundled out a new, second-generation Hemi.


273/318 LA Series V-8s

Chrysler introduced a low-cost engine to supplant the Red Ram units for its entry-level Plymouth line in 1956. These were incredibly efficient and durable engines for their era, able to rack up huge mileages, which made them ideally suited for use in garden-variety sedans and pickups. Initially offered in 277- and 303-ci versions, the lineup was expanded to also include motors in 301-, 318- and 326-ci forms. In 1964, Chrysler introduced an updated version, the LA (with L standing for lightweight). This featured a heavily revised block that incorporated thinwall casting and new heads with smaller wedge-type combustion chambers and a simpler valvetrain design. Not only was it lighter than the old A series, but it was physically smaller too, allowing it to fit in the compact A-body Dodge Dart and Plymouth Valiant with few issues.

Initially offered as a 273-ci unit with a 3.31-inch bore and 3.63-inch stroke, it came with a two-barrel carburetor and was rated at 180 hp. The following year, a four-barrel carb was offered, allowing for 235 hp and 285 lb ft of torque. Thanks to its short stroke, which allowed it to rev, it enabled the new Dodge Dart GT to run solid 16s in the quarter mile. With the original A-series 318 bowing out after 1967, the LA was given a new crank and longer 3.91-inch stroke to create a “new” 318. Although primarily offered in two-barrel form, this extremely durable engine would become a Chrysler mainstay, powering a succession of cars and trucks all the way through the 1970s and up until 2003. Four-barrel versions were developed in the late 1970s to cope with emissions requirements in California and high altitude areas, leading to the “interceptor” engines that became a mainstay in Chrysler’s M-body police pursuit cars during the 1980s. Ultimately, the venerable 318 gained fuel injection, in which form (5.2-liter Magnum) it was used to power Jeeps and Dodge trucks.


B-series 350/361

Designed to replace the original Hemi at the lower end of the spectrum, the B-series was conceived as a simple, relatively large displacement engine. It featured wedge-type combustion chambers and single rocker arms for each valve, along with a five-main bearing, forged steel crankshaft, forged steel connecting rods and hydraulic valve lifters. Although the early versions, first seen in 1958, were of 350- and 361-ci displacements, these were actually classed as big block engines, featuring a 4.06-inch bore (4.31 on the 361) and 3.38-inch stroke. The DeSoto version of this engine was dubbed the Turboflash, the Dodge equivalent Red Ram and the Plymouth version Sonoramic Commando. In 1958, a small number of both the 350- and 361-ci engines were equipped with a novel Bendix fuel injection system. Although highly advanced, it proved problematic, and nearly all the engines were recalled to have carburetors fitted. Soon joining these initial B-series V-8s was a larger 383 (discussed separately). The 361-ci version in particular proved hugely adaptable, suiting both regular and high-performance applications with two or four-barrel carburetion.

In 1961, as the first emissions regulations came into effect, the 361 received a closed crankcase ventilation system for cars sold in California, in which fumes from the case were drawn back into the carburetor and burned off in the combustion chamber to reduce exhaust emissions. At the same time, DeSoto dropped the compression on its version from 10.5:1 to 9.6:1, allowing it to run on regular fuel without any sacrifice in performance, thanks to adopting bigger valves. Although the 361 was discontinued in Dodge and Plymouth passenger cars after 1966, it remained in production for middle-weight trucks and commercial vehicles well into the 1970s.


426 Hemi V-8

The most famed Chrysler V-8 of all time was initially planned as pure race engine with one single objective – to trounce Ford and Chevrolet in NASCAR competition. In 1963, Chrysler top brass met to approve a new engine design to supplant the Wedge as the company’s new track weapon. Engineers Don Moore and Tom Hoover advocated that, given the company’s experience with the original Hemi in the 1950s, a new version would be key to achieving competition success this time around. Using the 426 Wedge engine’s block as a starting point, the “new” Hemi featured stronger bottom end webbing and thicker crank journals as well as four-bolt main caps. The massive aluminum cylinder heads required a redesigned head bolt pattern, and a single plane intake, solid lifter valvetrain and aggressive camshaft were specified to maximize power in the upper echelons of the rpm scale. Although it took a while to address a few issues, namely cracking on the cylinder walls and oiling problems, the new engine showed huge potential in testing, capable of generating more than 600 hp on the dynometer! At the Daytona 500 on February 23, 1964, onlookers were stunned as Hemi-powered Plymouths swept the top three spots. The winner, Richard Petty, went on to win the 1964 NASCAR Grand National Championship. This amazing performance turned stock car racing on its ear, and for 1965 NASCAR banned the Hemi, leaving it to contend on the nation’s dragstrips, where it once again asserted dominance in the hands of drivers like Al Eckstrand, Dick Landy and Arlen Vanke.

Tom Hoover said in a 1994 interview that there had been no plan to originally introduce a street Hemi, but the concept was relatively straightforward. By tilting the combustion chambers, Tom and fellow engineer Frank Bilk were able to shorten the exhaust valves, narrowing the head angle and enabling the engine to be dropped right in regular Dodge and Plymouth cars (even intermediates), without requiring the need for special exhaust manifolds. To save on cost and promote greater durability, street Hemis featured cast iron instead of aluminum heads, lower 10.25:1 compression pistons and a different intake manifold, but the blocks still sported four-bolt mains.

The Hemi first became available as a street engine in the 1966 Coronet/Satellite hardtops and convertibles, as well as the new Coronet-based Charger fastback. Fitted with dual Carter AFB 3084 four-barrel carburetors it was rated at 425 horsepower and 490 lb-ft of torque, outputs that would not change throughout the engine’s entire production run. For 1967, it was offered in a variety of specialty muscle cars, including the Dodge Coronet and Charger R/T, the Plymouth GTX, and for 1968, the no frills Super Bee and Road Runner. In one of these cars, it was possible to run the quarter mile in the 11 second range. Not surprisingly, the “new” Street Hemi soon gained a fearsome reputation on the street, though a high price (it retailed for $450 or more) and lack of drivability (it had a reputation for fouling plugs and bogging at low rpm) meant that cars equipped with it were seldom seen on Saturday night grudge matches. With the 1970 introduction of a hydraulic lifter cam to improve street performance, plus swoopy new E-body pony cars to install it in, the Street Hemi reached the zenith of cult status. Emissions, fuel economy standards and cost eventually did it in, but such was the Hemi’s reputation that surviving cars equipped with these engines are now the epitome of collectible muscle cars, regularly trading hands well in six-figure territory. In 2003, after a 32-year absence, Chrysler reintroduced the 426 Hemi as a built to order crate engine, ensuring its popularity for many years to come.


LA 340 V-8

Although the 318 was primarily a low-po unit, the basic LA design showed tremendous performance potential. The high-revving 273 of 1965-66 proved that this engine could run with the best of them, so in 1967, Chrysler released another high performance version, the 340. Retaining the same stroke as the 318 but using a larger 4.13 inch bore, this became one of the best high-performance V-8 engines of the late 1960s and early 1970s. Other changes included a Carter AVS four-barrel carburetor and high-rise dual plane intake manifold for optimal street performance, plus a double timing chain and oil pan windage tray to promote higher rpm durability and high performance cylinder heads with big 2.02-inch intake and 1.60-inch exhaust valves. Early versions featured forged steel crankshafts and high 10.25:1 compression. Despite being rated at a relatively modest 275 hp and 340 lb-ft, the high revving 340 was a giant killer. In the compact A-body Barracudas, Darts and later Dusters and Demons, it could run rings around 383-equipped intermediates. In 1971, it got a new 850 cfm Carter ThermoQuad carburetor. The following year, it was considerably detuned (down to an 8.5:1 compression ratio) and got revised heads, with smaller valves. A cast crank arrived for 1973, as did a new dual-plane manifold with Exhaust Gas Recirculation Provisions, to help reduce emissions. The 340 was discontinued after 1973, though its legacy lived on in the LA 360, which became a police favorite and able performer all the way through the smog years. As late as 2002, versions of the 360 (with EFI) were still being offered in the Dakota R/T, Ram pickups and Durango SUVs.


RB-series 383 V-8

Along with the 350/361, Chrysler introduced a bigger counterpart, the 383, beginning in 1959. A fairly large engine by all accounts, thanks to its 4.25-inch bore and 3.38-inch stroke, it was among the first motors to be designed by Chrysler’s new corporate engineering department. It featured a cast-iron block, thick bottom end webbing, a forged steel, five-bearing crankshaft and hydraulic lifter camshaft. In 1960, it became available with the company’s highly touted cross-ram intake manifold system, which used dual four-barrel carburetors, each suspended on very long intake runners, that drew air and fuel into the manifold. Looking like something from outer space, this system was designed to promote mid range torque and get the heavy full-size Chrysler, Dodge and Plymouths moving, particularly when accelerating onto the new interstate highway system or passing slow moving traffic on winding two-lane roads. In 1960 cross-ram form, it was rated at a fairly stout 330 horsepower and a monstrous 460 lb-ft of torque, its twisting power almost matching the larger 413, 426 and later 440 engines that shared the same basic design (the regular four-barrel version was pegged at 325 hp and 425 lb-ft).

In 1962, Chrysler introduced an RB version of the 383 with a raised deck height (requiring a wider intake manifold), a smaller 4.03-inch bore, and longer 3.75-inch stroke.  Equipped with two four-barrel carburetors, it churned out a mighty 343 hp and, thanks to its incredibly torquey nature, had, by 1965, become a staple in full-size C-body Dodge and Plymouths, as well as becoming a popular engine for police use. Three years later, the RB 383 entered perhaps its finest hour, selected as the base engine for no frills Road Runner and Super Bee B-body intermediates. For duty in these cars, it was fitted with a dual-plane cast iron intake manifold borrowed from the big 440, a Carter AVS four-barrel carburetor, hydraulic camshaft with 268/284 degrees duration and free-breathing heads, also inherited from the 440 Magnum/Super Commando. Rated at 335 hp, it was a torque monster, packing 420 lb-ft at a very useable 3400 rpm. As a result, it made these 3500-lb cars some of the quickest of the era. In fact, they were so fast, legend has it they became a favorite with moonshine runners. For 1971, due to impending emissions requirements, the 383 was detuned down to 300 hp and 410 lb-ft of torque. However, until its dying day, it remained a strong, torquey engine. The fact that Chrysler built well over one million of them is testament to its strength and popularity.


RB-series 440

Bigger brother to the 383 was the Raised B-series 440 V-8, created by enlarging the bore to 4.32-inches. It was designed to haul the big C-body Chryslers, Dodges and Plymouths around and was first introduced in 1966 as a replacement for the 426 Wedge engine. The following year, a high performance version of the 440 was released for Dodge and Plymouth cars. The former division called it the 440 Magnum, the latter, the Super Commando. Like the 383, the 440 featured a deep skirt block that employed thin wall casting technology (part of the reason such a large bore was possible), along with a stout cast iron crankshaft, ultra sturdy bottom end bearings, hydraulic valve lifters and cast-iron wedge type heads. Fuel and air were ingested via a Carter AFB four-barrel carburetor (larger AVS from 1968 onwards) and dual-plane cast-iron intake. The high performance version as fitted to the 1967-70 Plymouth GTX and Dodge Coronet R/T, and was rated at 375 horsepower at 4600 rpm and 480 lb-ft of torque at just 3200 revs.

On the street, it was a strong runner and could keep up with a Hemi to around 70-80 mph or so, after which the 426’s better breathing heads and more aggressive valvetrain held the advantage. The 440 proved to be Chrysler’s longest lasting RB-series big-block and was available in both civilian and police cars through the 1978 model year. Even towards the end, the big 440 proved very popular with those who needed a good towing engine. Law enforcement officers praised its tractable nature, supreme durability and strong mid-range punch, which made it ideal for pursuit work. Over 700,000 RB 440s were produced during the engine’s 12-year production run, an impressive number by all accounts.


RB 440 Six Pack

The saga surrounding this engine begins in 1968, as the muscle car wars were really starting to heat up. Chrysler was already packing a serious punch on the engine front, but the Corporation decided to trot out yet another high performance street engine part way through 1969. Legend has it that a group of engineers went to California and bought a fist full of Edlebrock high-rise aluminum intakes set up for triple carburetion. They then got their hands on a whole truckload of Holley two-barrel 2300 carburetors and went to work. In order to maximize performance and reliability, the carbs were spaced equidistant from each other on the manifold. In normal driving, the center carb was active, but punching the throttle activated the two outer units, giving a total swallowing capacity of around 1200 cubic feet per minute. Other engine modifications ran to a dual-point distributor and ignition, chrome flashed valve stems, heavy-duty valve springs borrowed from the Hemi and a unique camshaft with low tappets, to ensure optimum reliability. Rated at 390 horsepower and 490 lb-ft of torque, which matched the Hemi, the Six Pack was initially installed in lightweight B-body Super Bee and Road Runner coupes with a Bulletproof Dana 60 rear end. The 440 Six Pak (as Dodge marketing dubbed it) and Six-Barrel (which Plymouth called it), was the ultimate street weapon and a good driver could ring honest 12-second quarter mile times, even on street tires.

The only problem Chrysler had was keeping up with demand, since Edelbrock couldn’t supply intake manifolds fast enough. As a result, for 1970, Chrysler tooled up its own cast-iron intake manifold for this engine and built a stronger bottom end for it, including a stouter crankshaft and thicker rods. This new setup also required new balancing, and the 1970 440 Six Pack was the first Chrysler engine to feature an externally mounted crankshaft damper. The right side exhaust manifold was also modified to fit a new heat control valve, which promoted better fume scavenging. In an effort to further broaden the engine’s appeal, it was also available in any B-body application, including the standard Road Runner, Super Bee, Coronet R/T, GTX and Charger R/T. It would return for one more season, but, like the fearsome Hemi, it became a victim in the quest for cleaner exhaust emissions and changing market tastes. Although the Hemi still grabs the spotlight, many a Mopar enthusiast will tell you that in terms of an all-out street engine, the 440 Six Pack was biggest and baddest of them all.


LA 340 Six Pack

As muscle car mania reached for the stratosphere, one aspect that proved particularly popular was Trans Am racing. In the Sports Car Club of America’s sedan class, group 2, enthusiasts got the chance to watch race-prepped versions of their favorite Mustangs, Camaros, Barracudas and Firebirds mix it up on the road course, in close quarter, all-out racing action. In order to compete in the series, production-based cars needed an engine that was under 305 cubic inches. This posed a problem for several manufacturers, including Chrysler, but for 1970, rule changes meant that teams could field a de-stroked version of a production car engine. As a result, Dodge and Plymouth, with their brand new E-body Challenger and Cuda, were able to qualify by using the high-revving 340. Although the race cars used a 305, their street counterparts ran with the bigger LA motor. However, to further enhance performance, it was given a few upgrades. The block casting was actually thicker on the Six Pack engine, to permit installation of four-bolt main caps on crank bearings two, three and four. Although the heads were virtually identical, featuring the big 2.02 and 1.60 intake/exhaust valves, they were given modified pushrod holes to accept beefier valvetrain components. The icing on the cake was a cast iron intake manifold, with three Holley two-barrel carburetors. Advertised power output was 290 hp at 4400 rpm, but most believed this was purely for insurance reasons, and if the torque output of 345 lb-ft at 3400 rpm was any indication, actual horse power was estimated to be around 350 or more. The 1970 Six Pack installed in the Challenger T/A or AAR ’Cuda was a serious street weapon, perfectly set up for stop light drags, even though the cars were conceived primarily as corner carvers. For 1971, although it was discontinued in these cars, the 340 Six Pack found a home in the A-body Dodge Demon and Plymouth Duster coupes, which, given their lighter weight, proved even more formidable on the street. It was also available for a short time in the B-body Road Runner, but with the curtain falling on high performance, high compression engines, it was put out to pasture in 1972, though the heads would live on, as part of the 360 four-barrel engine.


B-series 400

This was the last gasp for the original B-series 383 big-block and was first introduced in 1972. It shared the original 383’s low block design and 3.38-inch stroke, but displacement was increased by boring the cylinders out to 4.34-inches. The reason for the 400’s introduction was primarily to satisfy tightening emissions requirements. Although it could be optioned with a four-barrel Carter ThermoQuad carburetor in 1972, it featured low compression (8.5:1) heads and was primarily a torque mover, though, rated at 255 net horsepower in four-barrel form, it was still a decent performer. It would last until 1978, by which time it had adopted Chrysler’s lean burn ignition system, along with chrome plated valve stems and hardened exhaust valve seats to cope with unleaded fuel, since the engine’s exhaust system incorporated a catalytic converter by then. In its final days, it found a home in the big C-body Chrysler Newports and New Yorkers, as well as Dodge Royal Monaco and Plymouth Gran Fury. It was also a staple of the original 1971-vintage intermediates, including the Monaco/Fury and semi-sporting Charger and Magnum.


Dodge Truck/Viper V-10

Perhaps one of the most intriguing Mopar engines of all was the 8.0-liter V-10, fitted to 1992-02 Dodge Vipers and the 1994-02 Ram Pickups. During the 1980s, plans were put in place to develop a new generation of torquey truck engine. Chrysler controlled Lamborghini at the time, and it was decided that they would work with the Italian company in development of this new powerplant. What emerged was a V-10 based on the LA series small-block V-8 (primarily to save tooling costs), with bore and stroke dimensions identical to the 360 (4.04 x 3.58-inches), though grafting on an extra pair of cylinders resulted in a total displacement of 488 cubic inches. The cast iron block featured a deep skirt design for maximum strength, and the crankshaft sported six main bearings. Rods were made from forged steel, and the pistons were cast aluminum with a special molybdenum coating to reduce friction, particularly during cold starting and break in. Although the basic engineering of this engine was undertaken at Chrysler, Lamborghini engineers were brought in to assist with development, specifically regarding weight savings, balancing the reciprocating assembly and optimizing cooling. What ultimately emerged were two engines, one that featured a cast-iron block and heads with a coil pack ignition and a returnless fuel system (rare for the time), designed for use in the upcoming Dodge Ram full-size pickup. The other was designed for Chrysler’s up-and-coming hyper sports car, the Dodge Viper. This latter version sported a lightweight cast aluminum block and heads, higher compression lightweight pistons, a special cross-ram intake manifold with twin throttle bodies, special high performance cylinder heads with bigger valves, and an oil pan designed to prevent starvation under extreme performance conditions. In addition, there was a special low-drag accessory drive and low-restriction exhaust manifolds. The Viper engine was rated at 400 hp and 490 lb-ft of torque, while the truck version cranked out 300 hp and 480 lb-ft of torque.

The distributorless ignition system and six-bearing, internally balanced crank allowed for a very smooth running engine, and the long intake runners gave it a real wallop in the torque department, enabling maximum grunt at a very low 1200 rpm. This meant that acceleration, both in the Viper and Ram ¾ ton and 1 ton trucks, was effortless, and it made both vehicles among the hottest performers in their segments. An improved “second generation” Viper engine was launched in the GTS coupe for 1996, and changes to the induction system and valvetrain boosted power to 450 hp, though torque output remained unchanged. In 2003, an entirely new V-10 with a larger bore and even more displacement (505-ci – 8.3-L) was introduced. Equipped with a version of this engine rated at 505 hp and 525 lb-ft, a new generation Dodge Ram, the sporty SRT-10, became the world’s fastest accelerating pickup, boasting a 0-60 mph time of just 4.8 seconds.


New Hemi V-8

After an absence of 32 years, the Hemi name once again began to adorn Chrysler vehicles beginning with the 2003 model year. This was due to an entirely new V-8 engine, designed to replace the aging 5.2 and 5.9-litre Magnum units. Displacing 345 cubic inches (5.7 liters), it featured a cast iron block with a deep skirt design and a fairly tall deck height compared to some rival engines. This was chosen based on input from data on the old 426 Hemi. Former engineer Tom Hoover suggested that a raised deck, with the camshaft mounted high up in the block, meant shorter pushrods could be used, allowing for simpler, lighter valvetrain components. The camshaft was also hollow to reduce weight, with extra large lobes to reduce load and wear on the lifters. The heads were cast aluminum pieces, with two valves for each cylinder, and, like the original 331 Hemi, dual rocker shafts. The combustion chambers weren’t true hemispherical in shape, since that would have made it very difficult to meet modern emissions requirements, but they were close enough. The new engine also featured a coil on plug ignition with two plugs per cylinder (another of Hoover’s suggestions), linked together via conventional ignition wires. This promoted better combustion, maximizing efficiency while reducing emissions. The new Hemi also sported sequential fuel injection and speed density metering to monitor air/fuel delivery, allowing the engine’s electronic brain to optimize spark settings. Another interesting feature was the so-called Multiple Displacement System (MDS). Part of the engine’s original design, this was an electronically operated cylinder deactivation system, in which four of the eight cylinders were shut down under light throttle loads in order to save fuel. Thanks to advanced algorithmic processing, the transition from four to eight cylinder operation was virtually undetectable and quick (the process taking approximately 40 milliseconds). The new Hemi was first seen in the 2003 ½ ton Dodge Ram pickups, where it was rated at 345 horsepower and 375 lb-ft of torque. It soon found a home in the Jeep Grand Cherokee, as well as Chrysler’s new rear-drive full-size LX cars, the 300C, Dodge Magnum and later Charger R/T where it was rated at 340 hp and 390 lb-ft. A special Performance Handling Group added an extra 10 hp on the Charger version.


SRT Hemi V-8

Besides the 345-ci version, a bigger 370-ci (6.1-liter) “new” Hemi arrived for 2006. It featured a larger bore and reinforced block, plus a forged micro alloy/steel crankshaft to cope with higher horsepower and engine load. In addition, it featured higher 10.3:1 compression pistons with special oil squirters at the bottom to increase lubrication and cooling, and a new oil pan and windage tray specified to maximize oil circulation, particularly under higher rpm operation. The cylinder heads were redesigned and fitted with bigger hollow stem valves. Stouter springs were also employed, and a special high strength hydraulic roller camshaft was specified. It also featured a redesigned fuel system with larger capacity injectors and less restrictive exhaust manifolds. Unlike the 5.7-liter unit, the bigger 6.1 didn’t feature the MDS system, but it sure packed a punch. With 425 horsepower and 420 lb-ft of torque, it propelled the Chrysler 300, Magnum and Dodge Charger SRT8s from 0 to 60 mph in well under five seconds, making them some of the quickest four-door cars on sale in North America, period.

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