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The Slant-6 is a Chrysler automobile engine, known within Chrysler as the G-engine. It is an inline-6 piston engine designed such that the cylinders are inclined at a 30-degree angle from vertical. The 30° inclination of the Slant-6 gives a lower height overall engine package, which enabled vehicle stylists to lower hoodlines, and also made room for the water pump to be mounted with a lateral offset, significantly shortening the engine's overall length. In addition, the slanted cylinder block provides ample space under the hood for intake and exhaust manifolds with runners of longer and more nearly equal length compared to the rake- or log-style manifolds typical of other inline engines. The Slant-6 manifold configuration gives relatively even distribution of fuel mixture to all cylinders, and presents less flow restriction. This, in turn, makes for relatively good airflow through the engine despite the intake and exhaust ports being on the same side of the head rather than in a crossflow arrangement.〔(The Chrysler Slant Six Engine (170-198-225) )〕 The engine was a clean-sheet design, led by Willem Weertman, later Chrysler's chief engine designer.〔(Willem Weertman - Chrysler Chief Engineer, Engine Design and Development )〕 It was introduced in two piston displacement sizes in 1960: The "LG" (Low-G, referring to the relatively short engine block casting and crankshaft stroke) in the Valiant, and the "RG" (Raised-G, referring to the relatively tall engine block casting and crankshaft stroke) in full-size Plymouth and Dodge Dart models. In 1960, the engine was called the "30-D Economy Six" engine by Plymouth marketers,〔(1960 Plymouth Cars: Fins' Final Fling )〕〔(1960 Plymouth advertisement in Life Magazine, October 1959 )〕 referring to the 30° cylinder block angle. The G-engine was offered in various configurations in the North American market until 1983 in cars, 1987 in trucks, and 1991 for marine, agricultural, and industrial use. Replacement engines were still being built in Mexico as of 2000. In addition, the G-engine was used extensively by worldwide Chrysler divisions and subsidiaries in their locally produced vehicles. It was also widely purchased by other original equipment manufacturers for installation in commercial vehicles, agricultural and industrial equipment, and boats. The G-engine gained a reputation for reliability and durability. The basic engine design is rigid and sturdy, in part because the engine was designed to be made of either iron or aluminum; an aluminum block was produced in 1961-1963, but most blocks were made of iron.〔 The block is of a deep-skirt design, with the crankshaft axis well above the oil pan rails for structural rigidity. Although only four main bearings are used, they are of the same dimensions as those in the 2G (1964-'71) Hemi. Efficient cooling and lubrication systems, a favorable ratio of connecting rod length to stroke, and a massive forged steel crankshaft (on engines made through mid-1976) all contributed to the engine's strength. The G-engine gave better performance than its competitors at its 1960 introduction, and generally kept up through the '60s and early '70s, though engines like the Pontiac OHC Six bested the performance of most versions of the slant-6, and after an early factory racing program was discontinued by 1962, the slant-6 did not receive much performance development; most slant-6s were equipped with a single 1-barrel carburetor. Starting in the early 1970s, primitive emission controls adversely affected driveability and power, though a version of the 2-barrel carburetor package first released for marine and export markets in 1967 was offered in North America from 1977 to 1983 under the "Super Six" name; performance figures were only slightly higher, but driveability was substantially improved.〔(Interview with Pete Hagenbuch, Chrysler engine development engineer )〕 Other Chrysler engines were released with more advanced combustion chambers, electronic fuel injection, and other modern improvements, but the length of the slant six precluded its use in Chrysler's front-drive cars, and a new V6 engine created by lopping two cylinders off the corporate LA V8 engine was devised for use in the new Dodge Dakota compact pickup truck for 1986. The Slant-6 engine was dropped from the rest of the Dodge truck line at the end of the 1987 model year, replaced by the 3.9 V6.〔 ==Significant production changes== *The combustion chamber shape was slightly modified for 1967 to promote more complete combustion and reduce exhaust emission toxicity. *All G engines used forged steel crankshafts until the middle of model year 1976, when a less costly cast-iron crankshaft was introduced. The cast crankshaft uses a different block, different main and connecting rod bearings and different connecting rods. *The counterbore in the rear flange of the crankshaft was a -inch diameter until 1967. For 1968, it was enlarged to inches. This difference has implications when swapping engines and automatic transmissions across this date line. *All G-engines used solid valve lifters through the 1980 model year, with the exception of a small production test of hydraulic lifters in the 1978 model year. For model year 1981, all North American G-engines received top-fed hydraulic lifters. Retrofitment in both directions is possible. *Emission control devices and systems, carburetor make and specification, and engine assembly details changed over the years to comply with market requirements and preferences. *Electronic ignition, which had been made available on V8 engines late in 1971, was made standard equipment on all engines including the RG in 1973. *Induction-hardened exhaust valve seats and upgraded exhaust valves were made standard in 1973 to withstand prolonged operation on no-lead fuel. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Chrysler Slant-6 engine」の詳細全文を読む スポンサード リンク
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