Chrysler ball-stud hemi

Last updated

The ball-stud hemi (known internally as A279 and affectionately as the BS Hemi) [1] was an automobile engine designed by Chrysler Corporation in the late 1960s. [2] It never entered production. [3]

Contents

Intended to deal with the troubles created by the low-production 426, of which only about 9,000 were built from 1966 to 1972), [4] as well as the different architectures of the higher-volume 383 cu in (6.3 L) and 400 cu in (6.6 L) B and 440 cu in (7.2 L) RB V8s, the ball-stud hemi was to be suitable for high-volume manufacture at low cost while generating high performance. [4] Chrysler hoped to replace three block and two head designs with the ball-stud design. [4] It was to be based on a low-deck block and available in 400 cu in (6.6 L) (4.34 by 3.38 in (110 by 86 mm)) [5] and 440 cu in (7.2 L)4.32 by 3.75 in (110 by 95 mm)) [5] displacements [4] (and Chrysler considered a 444 cu in (7.3 L), [4] which could have used stock 4.34 in (110 mm)400 cu in (6.6 L) pistons), [5] while the new valvetrain would cut both weight and cost, [4] as well as making it possible to fit it in a greater variety of models. [4]

The A279 initially used the B-block head bolt pattern, which "badly hampered" its exhaust ports, [1] forcing the use of a serpentine flow around some of the outer bolts [1] This was changed late in development, [1] but not before some tooling based on the original design had already been created. [1] This meant the head was not truly hemispherical, but had more intake port area than exhaust (3.575 in2 (23.06 cm2)versus (2.488 in2 (16.05 cm2)). [1]

Its intake valves were nearer the intake manifold, exhaust valves nearer the exhaust pipes. [1] The staggered "poly" arrangement improves airflow by "reducing valve shrouding and eliminating the sharp runner turns" of inline valve arrangements. [1] It also had equally spaced intake ports (similar to the 428SCJ), thereby achieving "more consistent mixture distribution" than the Wedges. [1] Chrysler used a 14 mm (0.55 in) spark plug, rather than the typical 18 mm (0.71 in), in an effort to fit it as centrally as possible in the combustion chamber. [1]

The intake and exhaust valves were the same size as the 426's, [6] the 2.25 in (57 mm) intake canted at 15° from the bore centerline, the 1.94 in (49 mm) exhaust at 6°. [6] By contrast, the B-block's were 2.08 in (53 mm) and 1.74 in (44 mm). [6]

Compared to the wedge, the ball-stud block had two additional clean-out holes to remove casting sand, because the large bore made coolant in the water jacket very significant, [6] and an additional oil drainback hole at either end of the block, due to demand for lubrication of the rocker arms. [1] Suggestions to increase the size of the oil pump pickup to 3⁄8 in (9.5 mm) (compared to the 426's 1⁄2 in (12.7 mm)) never passed the endurance testing stage. [6]

Pistons were to be cast aluminum. [6] Compression ratio was targeted as 10.5:1; on the surviving engine, it was measured at 9.8:1. [1] Forged connecting rods used the Wedge's 3⁄8 in (9.5 mm) hardware, as opposed to the Hemi's 7⁄16 in (11.1 mm), but would nonetheless have been considered high-performance parts. [1]

The intake was to be a single Carter ThermoQuad, of greater flow than any previously used, on a dual-plane intake manifold, [5] while dual four-barrels were never even considered, in the face of toughening emissions standards. [1] A split-level (vertically split, rather than horizontally divided) intake was also experimented with. [5]

Chrysler hoped to have the ball-stud in production sometime between 1971 and 1973. [4] In testing, it proved able to outperform the single four-barrel carburetted A134 440, and lagged behind the eight-barrel A102 426 Street Hemi. [7] About one year of development was put in before the project was stopped, in late 1969. [4] It was a victim of increasing demand for emissions controls and a reduction in emphasis on performance, as the "horsepower wars" wound down. [4] Moreover, Chrysler was suffering "severe financial stresses" that nearly brought the company down, [8] so the new production tooling and facilities were now uneconomic. [4]

Estimates of the number built vary from three to twelve. [4] Only one is known to survive. [4]

See also

Notes

  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Kirschenbaum, p.72.
  2. ↑ Kirschenbaum, Al. "Mopar Mystery Motor", in Hot Rod, 3/86, p.71.
  3. ↑ It should not be confused with Chrysler Australia's 245 cu in (4.0 L) Hemi-6. Kirschenbaum, p.72.
  4. 1 2 3 4 5 6 7 8 9 10 11 12 13 Kirschenbaum, p.71.
  5. 1 2 3 4 5 Kirschenbaum, p.78.
  6. 1 2 3 4 5 6 Kirschenbaum, p.74.
  7. ↑ Kirschenbaum, p. 71.
  8. ↑ Kirschenbaum, pp.71-2.

Sources

Related Research Articles

<span class="mw-page-title-main">Plymouth Road Runner</span> Type of muscle car manufactured by Plymouth

The Plymouth Road Runner is a mid-size car with a focus on performance built by Plymouth in the United States between 1968 and 1980. By 1968, some of the original muscle cars were moving away from their roots as relatively cheap, fast cars as they gained features and increased in price. Plymouth developed the Road Runner to market a lower-priced, basic trim model to its upscale GTX.

<span class="mw-page-title-main">Hemispherical combustion chamber</span>

A hemispherical combustion chamber is a type of combustion chamber in a reciprocating internal combustion engine with a domed cylinder head notionally in the approximate shape of a hemisphere. An engine featuring this type of hemispherical chamber is known as a hemi engine.

<span class="mw-page-title-main">Ford FE engine</span> Motor vehicle engine

The Ford FE engine is a Ford V8 engine used in vehicles sold in the North American market between 1958 and 1976. The FE was introduced to replace the short-lived Ford Y-block engine, which American cars and trucks were outgrowing. It was designed with room to be significantly expanded, and manufactured both as a top-oiler and side-oiler, and in displacements between 332 cu in (5.4 L) and 428 cu in (7.0 L).

<span class="mw-page-title-main">Plymouth Barracuda</span> Car model

The Plymouth Barracuda is a two-door pony car that was manufactured by Plymouth from 1964 to 1974.

<span class="mw-page-title-main">Dodge Dart</span> Motor vehicle

Dodge Dart is a line of automobiles marketed by Dodge from the 1959 to 1976 model years in North America, with production extended to later years in various other markets.

<span class="mw-page-title-main">Ford small block engine</span> Motor vehicle engine

The Ford small-block is a series of 90° overhead valve small block V8 automobile engines manufactured by the Ford Motor Company from July 1961 to December 2000.

<span class="mw-page-title-main">Chrysler B engine</span> Motor vehicle engine

The Chrysler B and RB engines are a series of big-block V8 gasoline engines introduced in 1958 to replace the Chrysler FirePower engines. The B and RB engines are often referred to as "wedge" engines because they use wedge-shaped combustion chambers; this differentiates them from Chrysler's 426 Hemi big block engines that are typically referred to as "Hemi" or "426 Hemi" due to their hemispherical shaped combustion chambers.

<span class="mw-page-title-main">Chrysler LA engine</span> Motor vehicle engine

The LA engines are a family of pushrod OHV small block 90° V-configured gasoline engines built by Chrysler Corporation. It was factory-installed in passenger vehicles, trucks and vans, commercial vehicles, marine and industrial applications from 1964 through 1991 (318) & 1992 (360). The combustion chambers are wedge-shaped, rather than the polyspherical combustion chambers in the predecessor A engine or the hemispherical combustion chambers in the Chrysler Hemi engine. LA engines have the same 4.46 in (113 mm) bore spacing as the A engines. LA engines were made at Chrysler's Mound Road Engine plant in Detroit, Michigan, as well as plants in Canada and Mexico. The "LA" stands for "Light A", as the 1956 - 1967 "A" engine it was closely based on and shares many parts with was nearly 50 pounds heavier. The "LA" and "A" production overlapped from 1964 - 1966 in the US and through 1967 in export vehicles when the "A" 318 engine was phased out. Willem Weertman, who later became Chief Engineer – Engine Design and Development, was in charge of the conversion. The basic design of the LA engine would go unchanged through the development of the "Magnum" upgrade (1992-1993) and into the 2000s with changes to enhance power and efficiency.

<span class="mw-page-title-main">Chrysler Slant-6 engine</span> Motor vehicle engine

The Slant-Six is the popular name for a Chrysler inline-6 internal combustion engine with an overhead valve reverse-flow cylinder head and cylinder bank inclined at a 30-degree angle from vertical. Introduced in 1959, it was known within Chrysler as the G-engine. It was a clean-sheet design that began production in 1959 at 170 cubic inches (2.8 L) and ended in 2000 at 225 cubic inches (3.7 L). It was a direct replacement for the flathead Chrysler straight six that the company started business with in 1925 until the old design was discontinued in the 1960s.

<span class="mw-page-title-main">Chrysler Hemi-6 Engine</span> Motor vehicle engine

The Chrysler Hemi-6 engine is a family of inline six-cylinder petrol engines produced by Chrysler Australia in three piston displacements and multiple configurations. Hemi-6 engines were installed in Australian-market Chrysler Valiants from 1970 through 1981. It was also installed in the Valiants closely related variants, the Chrysler VIP, the Chrysler by Chrysler & the Valiant Charger.

<span class="mw-page-title-main">Chevrolet big-block engine</span> American V-8 car engine

The Chevrolet "big block" engine is a term for a series of large-displacement, naturally-aspirated, 90°, overhead valve, gasoline-powered, V-8 engines; that were developed and produced by the Chevrolet Division of General Motors, from the 1950s until present.

<span class="mw-page-title-main">Pontiac V8 engine</span> Motor vehicle engine

The Pontiac V8 engine is a family of overhead valve 90° V8 engines manufactured by the Pontiac Division of General Motors Corporation between 1955 and 1981. The engines feature a cast-iron block and head and two valves per cylinder. Engine block and cylinder heads were cast at Saginaw Metal Casting Operations then assembled at Tonawanda Engine before delivery to Pontiac Assembly for installation.

<span class="mw-page-title-main">Dodge Coronet</span> American car model sold 1949–1959, 1965–1976

The Dodge Coronet is an automobile that was marketed by Dodge in seven generations, and shared nameplates with the same bodyshell with varying levels of equipment installed. Introduced as a full-size car in 1949, it was the division's highest trim line and moved to the lowest level starting in 1955 through 1959. The name was reintroduced on intermediate-sized models from the 1965 until 1976 model years. Muscle car versions were available starting in 1965 with the 383 and 426 wedge cu in Chrysler RB engine, followed in 1966 by the powerful 426 cu in Chrysler Hemi. Other performance models included the "Superbee", and featured, the 383 cu in Magnum, among other engine options. The nameplate "coronet" is a type of crown worn by royalty.

Ford developed the MEL ("Mercury-Edsel-Lincoln") engine series as the replacement for the Lincoln Y-block V8 engine for use in large passenger car applications. These engines were produced in Lima, Ohio at Ford's Lima Engine plant. They were in turn replaced by the 385 series engines.

<span class="mw-page-title-main">Chrysler Hemi engine</span> Series of I6 and V8 engines built by Chrysler

The Chrysler Hemi engines, known by the trademark Hemi, are a series of American V8 gasoline engines built by Chrysler with overhead valve hemispherical combustion chambers. Three different types of Hemi engines have been built by Chrysler for automobiles: the first from 1951 to 1958, the second from 1964 to 1971, and the third beginning in 2003. Although Chrysler is most identified with the use of "Hemi" as a marketing term, many other auto manufacturers have incorporated similar designs. The engine block and cylinder heads were cast and manufactured at Indianapolis Foundry.

<span class="mw-page-title-main">Plymouth GTX</span> Motor vehicle

The Plymouth GTX is an automobile introduced as the Belvedere GTX in 1967 by the Plymouth division. It was positioned as a mid-sized upscale-trimmed performance muscle car through the 1971 model year.

<span class="mw-page-title-main">Dodge Charger (1966)</span> American specialty car model by Dodge

The Dodge Charger (1966), also known as Dodge Charger (B-body), is a mid-size automobile that was produced by Dodge from 1966 to 1978, and was based on the Chrysler B platform.

The Polyspheric or Poly engines were V8 engines produced by Chrysler from 1955 to 1958 as lower-cost alternatives to the Hemi engines. These engines were based on the Hemi engines, using the same blocks and crankshaft parts, but completely different cylinder heads, pushrods, exhaust manifolds and pistons.

Tom Hoover was the leading engineer of the Chrysler 426 Hemi engine.

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.