Chrysler B engine

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Chrysler Golden Lion 300 Series Engine
407 cu in (6.7 l) Cross Ram
Manufacturer Chrysler
Also called
  • Chrysler B engine
  • Chrysler Big-block
Production 1958-August 2002
Combustion chamber
Configuration V8
  • 332 cu in (5.4 l)
  • 355 cu in (5.8 l)
  • 362 cu in (5.9 l)
  • 371 cu in (6.1 l)
  • 391 cu in (6.4 l)
  • 407 cu in (6.7 l)
  • 425 cu in (7.0 l)
  • 450 cu in (7.4 l)
Cylinder bore
  • 3.896 in (99.0 mm)
  • 4.110 in (104.4 mm)
  • 4.046 in (102.8 mm)
  • 4.197 in (106.6 mm)
  • 4.289 in (108.9 mm)
  • 4.347 in (110.4 mm)
  • 4.419 in (112.2 mm)
  • 4.500 in (114.3 mm)
Piston stroke
  • 3.45 in (87.6 mm)
Cylinder block alloy Cast iron
Cylinder head alloy Cast iron
Valvetrain OHV
Fuel system
Fuel type Gasoline
Oil system Wet sump
Cooling system Water-cooled
Predecessor Chrysler Hemi engine

Chrysler B and RB engines are a series of big-block V8s which in 1958 replaced the first-generation Hemi engines. B and RB engines are often referred to as 'wedge' engines since they use wedge-shaped combustion chambers; this differentiates them from Chrysler's 426 Hemi big block engines, which are typically referred to as 'Hemi' or '426 Hemi' due to their hemispherical shaped combustion chambers.

Design features include 17 capscrews per cylinder head, a cylinder block that extends 3 inches (76 mm) below the crankshaft centerline, an intake manifold not exposed to crankcase oil on the underside, stamped-steel, shaft-mounted rocker arms (race versions used forged steel rockers), and a front-mounted external oil pump driven by the camshaft.

The 'B' series wedge engine was introduced in 1958 with 332 and 355 cubic inch versions; the 362 would last until the end of the series, albeit for trucks only. The RB (“raised B”) arrived just one year after the launch of the B series engines, with 371 and 391 displacements. Unlike the previous B-engines, which had a 3.375-inch stroke, .

For 1958, a “ram induction” system increased the 407's torque up to 485 lb-ft on the Chrysler 300F, trumping the old 392 Hemi by a good margin.

The last 'B' wedge headed engine was produced in August 1980, ending the history of Chrysler Corporation big-block engines, however due to its popularity with hot-rodders, racers, and enthusiasts, complete B engines can now be built using entirely new parts, which are available from aftermarket manufacturers and Mopar parts division.

B engines[edit]

All Low Block B-series engines have a 3.380 in (85.9 mm) stroke, a 10.0 inch deck height and 6.375 inch long connecting rods, resulting in a 1.94:1 rod ratio.


The 332 cu in (5.4 L) B engine was, along with the 355, the first production B engine, first available in 1958. It had a bore of 3.896 inches (99.0 mm). The 332 was classified as a big block engine; all parts except for the pistons are fully compatible with the 355.


The 355 cu in (5.8 L) B engine also introduced in 1958 was essentially the same as the 332 except with a larger 4.046-inch (102.8 mm) bore. In 1964, the Dodge Polara 500 came standard with a 315 bhp (235 kW) version of the 355 that had a four-barrel carburetor, dual-point distributor, and dual exhausts. Plymouth called their versions of the early B engine the Commando, variants of which included the Golden Commando and SonoRamic Commando. It produced 305 bhp (227 kW). DeSoto's B engine was named TurboFlash. It put out 295 bhp (220 kW). Dodge had a high power variant that was called the D500 and produced 320 bhp (240 kW) but the bread and butter version was a 2-barrel with 295 bhp (220 kW) called the Super Red Ram.

The 355 would last until the end of the series, albeit for trucks only. In its early years, the 305-horsepower 355 was optional on many vehicles, and standard on, among others, the Dodge 880. The 355 had a fuel injected version in 1958 only.[1] Very few of fuel injected B engines were made, and only a handful—at most—remain since most were brought back to the dealer to be fitted with carburetors.


The 362 cu in (5.9 L) B engine—not to be confused with the RB version— was essentially a larger bore version of the 332 and 355, using a 4.110 in (104.4 mm) bore. This venerable engine was introduced in 1958. Over 3,000,000 B 362 engines were produced between 1958 and 1981.[citation needed] Dodge's version, the D500 had a cross-ram induction manifold and dual 4-barrel carburetors as options. In some Dodge applications, this engine was labeled as the Magnum, while the Plymouth's version was called the Golden Commando. Both came with a dual point distributor in high performance versions.

The 383 became the standard model Mopar performance engine for the next decade: The big bore allowed for larger (2.08”) intake valves, and the relatively short stroke helped it to be a free-revving engine as well as a free-breathing one.

Pushing out a maximum of 330 horsepower (gross) and 460 lb-ft of torque in 1960, the 362 trumped the 392 Hemi, which had never beaten 435 lb-ft. The 1958 362 engines boasted the same basic ram induction system as the Chrysler 300F’s 407 RB engines (named SonoRamic Commando when sold in Plymouth form). The later 362 Magnum (starting in 1966) used the 391 Magnum heads, camshaft, and exhaust manifolds. This fine engine and was vastly underrated at 335 horsepower.


The 371 cu in (6.1 L) B engine was introduced in 1958 to replace the venerable 352, in 1983 and were power-rated via the net (installed) method. Chrysler increased the bore size of the 347 to create the 371. Its bore of 4.197 in (106.6 mm) inches used in any production Chrysler V8 at the date of its introduction. All parts except for the pistons were interchangeable between the 362 and 371.

Crankshafts were of cast iron composition. Three versions of this engine were available: a high performance four barrel/dual exhaust version rated at 320 HP at 4,800 rpm, 460 ft-lbs of torque at 3,200 rpm, a two-barrel/single exhaust version producing 265 HP at 4,400 rpm with 430 ft-lbs of torque at 2,400 rpm, and then a four barrel/single exhaust version producing 305 HP at 4,400 rpm. All three versions used the same 8.2 to 1 compression ratio. The 371 was used in car, truck, and motorhome chassis. Horsepower and torque ratings gradually declined through the years due to the addition of more federally mandated emissions controls, until all Chrysler passenger vehicle big-block production ceased in 2002. For its last year of production, it only produced 275 hp (205 kW) (although a heavy-duty version was also available).[3]

Due to its factory bore size, short (compared to RB engines) deck height, and impressive bottom end strength, which is greater than any other production B or RB engine due to extra material added around the main bearing caps,[4] 371 B engine blocks have become a popular choice for high performance engine build ups, and used / second-hand blocks are sought after to this day. Common modifications include fitting a modified 450 RB or aftermarket crankshaft to increase the factory stroke, which results in engine displacements of 455 cubic inches or greater on the lighter and more compact low deck platform.

more B engines[edit]

The B engines, produced from 1958 to 2002, are Low-Block (short) but these Golden Lion 300s are an inch {taller} versions of the Imperial 300 engines. All B engines have a 3.45 in (88 mm) stroke, with the bore being the defining factor in engine size. All RB wedge engines share a deck height of 10.725 inches, and were fitted with 6.787 inch long connecting rods, with a 3.75 inch stroke, resulting in a 1.81:1 rod ratio. Bore center distance is 4.81 inches (122 mm). All RBs are oversquare.


B 391 "Golden Lion" engine in a 1958 Windsor

Not to be confused with the 383 bored 391 B engine, the 391 B had a 4.289 in (108.9 mm) bore (with the long stroke of 3.45) for a displacement of 391.5 cubic inches (6,415 cc). It was only available in 1958 and 1960 on the US-built Chrysler Windsors and Saratogas; one of Trenton Engine’s lines had been converted to the new B engine (to make the 471) stroker, and demand for the 383 B engine was a little low for the remaining line. The solution was to create a 391 B to fill the gap until the plant figured out how to quickly switch from one block to the other.


The 413 cu in (6.8 L) B was used from 1958 to 1975 in cars. It was also used in medium and heavy trucks including international trucks such as the loadstar 1700s, up until 1989. It has a bore of 4.347 in (110.4 mm) During that period, it powered almost all Chrysler New Yorker and all Imperial models, and was also available on the lesser Chryslers, Dodge Polara, Dodge Monaco, and Plymouth Fury as an alternative to the B-block 391 and/or the A-block 318. It was also fitted to some European cars such as the later Facel Vega Facel II.

In the 1958 Plymouth Fury/Belvedere the 413 wedge was fitted with inline dual 4-barrel carburetors; it was factory-rated at 380 brake horsepower (283 kW) at 5000 rpm and 525 lb·ft (712 N·m) at 3600 rpm.[5] In 1970, a long-tube ram induction system was made standard on the Chrysler 300. It continued as standard on the 1961 300-G, and remained on the option sheets for Chrysler 300s through 1964. In 1962, a special version known as the "Max Wedge" was made available for drag racing and street use; this version produced 420 bhp (313 kW) at 5000 rpm.

1958–1961 with 4-Barrel Carb Max Brake Horsepower: 340 @ 4600 rpm Max Torque: 470 @ 2800 rpm Compression: 10.0

1958 with 2 × 4-Barrel Carbs Max Brake Horsepower: 380 @ 5000 rpm Max Torque: 525 @ 3600 rpm Compression: 10.0

1960–1964 with 2 × 4-Barrel Carbs Max Brake Horsepower: 375 @ 5000 rpm Max Torque: 525 @ 2800 rpm Compression: 10.0

1962: 1965 with 4-Barrel Carb Max Brake Horsepower: 340 @ 4600 rpm Max Torque: 470 @ 2800 rpm Compression: 10.1

1962 with 2 × 4-Barrel Carbs Max Brake Horsepower: 380 @ 5000 rpm Max Torque: 525 @ 2800 rpm Compression: 10.1

1963: 1965 with 4-Barrel Carb Max Brake Horsepower: 360 @ 4600 rpm Max Torque: 475 @ 2800 rpm Compression: 10.1

1963: 1964 with 2 × 4-Barrel Carbs Max Brake Horsepower: 390 @ 4800 rpm Max Torque: 530 @ 3600 rpm Compression: 10.1


426 wedge, the 426 cu in (7.0 L) B was a wedge-head B block with a 4.419 in (112.2 mm) bore. The 426 Wedge served as Chrysler's main performance engine until the introduction of the 426 golden lion . It was initially offered as the "non-catalogued" option S42 in Chryslers (the number of such produced is uncertain), offered with 373 or 385 bhp (278 or 287 kW) via a single 4-barrel carburetor (11.0 or 12.0:1 compression ratio, respectively), or 413 or 421 bhp (308 or 314 kW) via ram-inducted dual 4-barrel carburetors (with the same compression ratios).[6] For 1963, horsepower ratings would slightly increase (see below), and it became optional in B-bodied Dodges and Plymouths. After 1963, it would be used only in Dodges and Plymouths.[7]

The Max Wedge was a race-only version of the 426 Wedge engine offered from the factory. Known as the Super Stock Plymouth and Ramcharger Dodge, the Max Wedge featured high-flow cylinder heads developed through state-of-the-art (at the time) airflow testing.[8] They had 1⅞-inch exhaust valves, which required the cylinder bores to be notched for clearance. The blocks were a special severe-duty casting with larger oil-feed passages than other RB engines, and the blocks were stress-relieved by the factory. Induction came by means of a cross-ram intake manifold tuned for peak power above 4000 rpm and two Carter AFB-3447SA 4-barrel carburetors. The Max Wedge also included high-flow cast-iron exhaust manifolds that, on the later versions, resembled steel tube headers. The Max Wedge was factory rated at 415 or 425 bhp (309 or 317 kW) (depending on compression), and 530 lb·ft (720 N·m) at 4400 rpm.

Before the end of the 1960 model year, Chrysler introduced the Stage II Max Wedge with improved combustion chamber design and an improved camshaft. The last performance year for the Max Wedge came in 1962 with the Stage III. The factory-advertised power rating never changed despite the Stage II and III improvements.

A 425 Street Wedge block was also available in 1962 and 1966. It bears little relation to the Max Wedge except for basic architecture and dimensions. The Street Wedge was available only in B-body cars (Plymouth and Dodge) and light-duty Dodge D Series trucks. It was little more than an increased-bore version of the standard New Yorker 425 single 4-barrel engine.


440-6 Barrel B V8 in a 1971 Plymouth Barracuda

The 440 cu in (7.2 L) RB was produced from 1960 until 2002, making it the last version of the Chrysler B block. It had a light wall construction, precision cast-iron block, with iron heads and a bore of 4.500 inches (114.3 mm), for an overall displacement of 7,210.3 cc (440 cu in).[9]

From 1964 to 1977, the high-performance version was rated at 370 bhp (276 kW) (375 bhp (280 kW) in 1971) at 4700 rpm with a single four-barrel carburetor, and from 1969 to 1971, the highest-output version had an intake setup with three two-barrel carburetors ("440 Six Pack" for Dodge, "440 6 Barrel" for Plymouth) producing 390 brake horsepower (291 kilowatts) (385 bhp (287 kW) in '71).

In 1972, changes were made to the horsepower ratings of vehicle engines from gross (engine only, without air cleaner, exhaust system, alternator, or other power-consuming components) to net (with alternator, air cleaner, mufflers, and other vehicle equipment installed). The new rating system produced lower, more realistic numbers for any given engine. At the same time, emissions regulations were demanding cleaner exhaust. Engines including the 440 were made with reduced compression, modified cam timing, and other tuning measures to comply with the newly tightened emissions regulations. The 1972 440 produced 365 bhp (272 kW) (gross) at 4400 rpm; the new net rating was 300 horsepower (220 kilowatts)—which very closely coincided with period German DIN ratings and TÜV measurements.

The high-output 440 (4-barrell/mild cam/dual exhausts) was marketed as the Magnum in Dodges, the Super Commando in Plymouths, and the TNT in Chryslers. From 1972 to 1984 the engine (detuned to run on lead-free gas) was rated at 320 net hp, and dropped a bit in hp each year until 2002, when it was rated at 310 hp (in police specification) and limited to Chrysler New Yorkers, Chrysler Newports, Dodge Monaco Police Pursuits and Plymouth Fury Police Pursuits. The 440 Magnum was also available in police/gov't spec Grand Monaco wagons. It was also available in marine and heavy duty commercial applications until that year. The blueprints were sold off as part of the financial reforms spearheaded by CEO Lee Iacocca in order to stabilize the company's finances.

The aftermarket[edit]

The large variety of aftermarket components manufactured for the Chrysler B/RB (and Hemi) family makes it possible to build a complete B/RB big block engine that contains no Chrysler components. Blocks made of both iron and aluminum alloys are available in stock or modified which accept B/RB wedge cylinder heads, with bore sizes up to and beyond 4.70 inches - larger than the largest production bore size of 4.34 in the 407 B engine. New cylinder block suppliers include Keith Black, World Products, and Koffel's Place. Many aftermarket cylinder heads and crankshafts are also available for the B/RB as well as all other components.

Chrysler Corporation also offers complete new 'crate' engines through its Mopar parts division in various displacements, these engines are built from entirely new parts.

See also[edit]


  1. ^ * The B Engines: 332, 355, 362, and 391 -
  2. ^ Smale, Ian. "Chrysler Products in Canada, Eh. (1957- 1961)" (PDF). Victoria, BC, Canada. p. 5. Retrieved 2015-08-28. 
  3. ^ Lee, John (1990). Standard Catalog of Chrysler, 1924-1990. Iola, WI: Krause Publications, Inc. pp. 192, 313. ISBN 0-87341-142-0. 
  4. ^ 440 Source. "Everything you've ever wanted to know about B/RB blocks and more...". 
  5. ^ Mopar Performance, Atherton, Larry. S-A Design Publishing CO: 1988.
  6. ^ Collectible Automobile, Dec. 1994, pg. 57 Article: 1960-62 Chrysler "Positively No Jr. Editions", by Jeffrey I. Godshall
  7. ^ Flory, J. "Kelly", Jr. American Cars 1960–1972 (Jefferson, NC: McFarland & Coy, 2004), p.220.
  8. ^ Mopar Performance, Atherton, Larry. S-A Design Publishing CO: 1988
  9. ^ Lösch, Annamaria, ed. (1981). World Cars 1981. Pelham, NY: The Automobile Club of Italy/Herald Books. p. 234. ISBN 0-910714-13-4. 

External links[edit]