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88-420: For 1958, Chevrolet models were redesigned longer, lower, and heavier than their 1957 predecessors. The first ever production Chevrolet big block V8, the 348 cu in (5,700 cc) , was now an option. Chevrolet's design for the year fared better than its other GM offerings, and lacked the overabundance of chrome found on Pontiacs, Oldsmobiles, Buicks and Cadillacs. Complementing Chevrolet's front design

176-643: A bore × stroke of 4 + 1 ⁄ 4  in × 4 in (108.0 mm × 101.6 mm). The 1970 Chevrolet Corvette LS-5 version of this engine was factory-rated at 390 bhp (395 PS; 291 kW) and 500 lb⋅ft (678 N⋅m), and the LS-6 engine equipped with a single 4-barrel 800 cu ft/min (23 m /min) Holley carburetor was upgraded to 450 bhp (456 PS; 336 kW) at 5600 rpm and 500 lb⋅ft (678 N⋅m) at 3600 rpm of torque . The AHRA ASA (Showroom Stock Automatic) Class record-holding Chevelle LS-6 for

264-539: A forged steel crankshaft . This dual-quad version was immortalized in the Beach Boys song titled " 409 ". In the 1963 model year, output reached 425 bhp (431 PS; 317 kW) at 6000 rpm and 425 lb⋅ft (576 N⋅m) at 4200 rpm of torque with the Rochester 2X4-barrel carburetor setup, a compression ratio of 11:1 and a solid lifter camshaft . The engine was available through mid-1965, when it

352-402: A 32° wedge-shaped combustion space ... The addition of two milled cutouts [in the head] to extend the volume of the combustion wedge can create a compression ratio of 7.5:1; one milled cutout produces a 9.5:1 compression ratio. The difference between the volume of these cutouts provides a wide compression range without making any changes in the piston or cylinder head. The number or size of cutouts

440-523: A 396 cu in (6.5 L) variant; however only the 427 cu in (7.0 L) engine (Mark IIS) was ever raced. It gained its nickname due to the incredible speeds cars equipped with it attained during its debut, being considerably faster than the well known W-series powered cars. The engine was first used in Mickey Thompson 's Z-06 Corvettes at Daytona in the 1963 Daytona 250 Miles – American Challenge Cup, and then in 1963 Daytona 500 where

528-443: A corresponding valve seat ground into the rim of the chamber being sealed. The shaft travels through a valve guide to maintain its alignment. A pressure differential on either side of the valve can assist or impair its performance. In exhaust applications higher pressure against the valve helps to seal it, and in intake applications lower pressure helps open it. The poppet valve was invented in 1833 by American E.A.G. Young of

616-422: A distinctive appearance. The W-series was produced from 1958 to 1965, in three displacements : The W-series engine was made of cast iron . The engine block had 4.84-inch (123 mm) bore centers, two-bolt main bearing caps, a "side oiling" lubrication system (the main oil gallery located low on the driver's side of the crankcase), with full-flow oil filter, and interchangeable cylinder heads . Heads used on

704-446: A few Chevrolet dealers as optional performance parts. The LS-7 was later offered as a crate engine from Chevrolet Performance with an officially rated power minimum of 500 hp (373 kW) gross. In 1971, the LS-5 produced 365 hp (272 kW) and 550 lb⋅ft (746 N⋅m), and the LS-6 option came in at 425 hp (317 kW) and 575 lb⋅ft (780 N⋅m). In 1972, only

792-469: A pulsed flow control is wanted. The pulse can be controlled by a combination of differential pressure and spring load as required. Presta and Schrader valves used on pneumatic tyres are examples of poppet valves. The Presta valve has no spring and relies on a pressure differential for opening and closing while being inflated. Poppet valves are employed extensively in the launching of torpedoes from submarines . Many systems use compressed air to expel

880-570: A raised-deck, four-bolt main bearing cap cylinder to accommodate an extra oil control ring on the pistons. Unfortunately, the raised deck design complicated the use of the block in racing applications, as standard intake manifolds required spacers for proper fit. Distributors with adjustable collars that allowed adjustments to the length of the distributor shaft also had to be used with 366 and 427 truck blocks. Mark IV engines also found themselves widely used in power boats. Many of these engines were ordinary Chevrolet production models that were fitted with

968-467: A reliable means of distinguishing a 348 from the larger engines. As with the 265 and 283 cu in (4.3 and 4.6 L) "small-block" engines, the W-series valve gear consisted of tubular steel pushrods operating stud-mounted, stamped-steel rocker arms. The push rods also acted as conduits for oil flow to the valve gear. Due to the relatively low mass of the valve train, mechanical lifter versions of

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1056-496: A second production line stock (but recently rebuilt and partially blueprinted) ZL1 revealed nearly identical figures for the various "gross" conditions. Period magazine tests of the ZL1 were quite rare due to the rarity of the engine itself. High-Performance Cars tested a production line stock, but well tuned, example and recorded a 13.1 second/110 mph (180 km/h) 1 ⁄ 4 mile (402 m), which correlates quite well with

1144-551: A single 3" catalytic converter. Mark IV engines saw extensive application in Chevrolet and GMC medium duty trucks, as well as in Blue Bird Corporation 's All American and TC/2000 transit buses (the latter up until 1995, using a 427 with purpose-built carburetor). In addition to the 427, a 366 cu in (6.0 L) version was produced for the commercial market. Both the 366 and 427 commercial versions were built with

1232-424: A substantially oversquare design. This engine was superseded by the 409 cu in (6.7 L) as Chevrolet's top performing engine in 1961 and went out of production for cars at the end of that year. It was produced through 1964 for use in large Chevrolet trucks. With a four-barrel carburetor , the base Turbo-Thrust produced 250 hp (186 kW). A special " Tri power " triple-two-barrel version, called

1320-529: A valve gear for double-beat poppet valves in 1842. Criticism was reported in the journal Science in 1889 of equilibrium poppet valves (called by the article the "double or balanced or American puppet valve") in use for paddle steamer engines, that by its nature it must leak 15 percent. Poppet valves have been used on steam locomotives , often in conjunction with Lentz or Caprotti valve gear . British examples include: Sentinel Waggon Works used poppet valves in their steam wagons and steam locomotives. Reversing

1408-415: Is a valve typically used to control the timing and quantity of petrol (gas) or vapour flow into or out of an engine, but with many other applications. It consists of a hole or open-ended chamber, usually round or oval in cross-section, and a plug, usually a disk shape on the end of a shaft known as a valve stem. The working end of this plug, the valve face, is typically ground at a 45° bevel to seal against

1496-462: Is a term for a series of large-displacement , naturally-aspirated , 90°, overhead valve , gasoline -powered, V8 engines ; that were developed and produced by the Chevrolet Division of General Motors , from the 1950s until present. Chevrolet had introduced its popular small-block V8 in 1955, but needed something larger to power its medium duty trucks and the heavier cars that were on

1584-485: Is developed at relatively low engine speeds, resulting in an engine with a broad torque curve. With its relatively flat torque characteristics, the "W" engine was well-suited to propelling both the trucks and heavier cars that were in vogue in the US at the time. The W-series was a physically massive engine when compared to the "small-block" Chevrolet engine. It had a dry weight of approximately 665 pounds (302 kg), depending on

1672-601: Is obtained at the drive wheels and thus takes into account drivetrain power loss of the transmission, driveshaft, and differential, as well as all accessories) does not equate to SAE net HP (which is horsepower at the flywheel, but with all essential peripherals included (such as the water pump, alternator, and air cleaner), accessories (such as a power steering pump, if fitted), a stock exhaust system, and all required emission controls, none of which are accounted for in SAE gross, which only measures gross flywheel horsepower). The RPO L89

1760-402: Is varied simply by adding or removing cutters." The first iteration of the W-series engine was the 1958 "Turbo-Thrust" 348-cubic-inch (5.7 L), originally intended for use in Chevrolet trucks but also introduced in the larger, heavier 1958 passenger car line. Bore and stroke was 4 + 1 ⁄ 8  in ×  3 + 1 ⁄ 4  in (104.8 mm × 82.6 mm), resulting in

1848-460: The 1963 Impala Sport Coupé , ordered under Chevrolet Regular Production Option (RPO) Z11. This was a special package created for drag racers , as well as NASCAR , and it consisted of a cowl-induction 427 cu in (7.0 L) engine and body with selected aluminum stampings. The aluminum body parts were fabricated in Flint, Michigan at the facility now known as GM Flint Metal Center. Unlike

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1936-597: The Newcastle and Frenchtown Railroad . Young had patented his idea, but the Patent Office fire of 1836 destroyed all records of it. The word poppet shares etymology with " puppet ": it is from the Middle English popet ("youth" or "doll"), from Middle French poupette , which is a diminutive of poupée . The use of the word poppet to describe a valve comes from the same word applied to marionettes , which, like

2024-456: The "Super Turbo-Thrust", produced 280 hp (209 kW). A "Special Turbo-Thrust" upped the power output to 305 hp (227 kW) with a single large four-barrel carburetor. Mechanical lifters and Tri power brought the "Special Super Turbo-Thrust" up to 315 hp (235 kW). For 1959 and 1960, high-output versions of the top two engines were produced with 320 hp (239 kW) and 335 hp (250 kW) respectively. In 1961, power

2112-444: The 122.15 mph (196.58 km/h) trap speed indicated low 11-second ET (elapsed time) potential (e.g. with larger drag slicks) and suggested something on the order of 495 hp (369 kW), "as installed", in that modified configuration. This large difference in power suggests that the OEM exhaust manifolds and exhaust system were highly restrictive in the ZL1 application, as was also

2200-589: The 187,000 1958 Chevrolet wagons built, only 16,590 of these were 2-door model Yeoman (not counting Delray Sedan Delivery), Chevrolet’s entry-level wagon. The Yeoman was dropped (along with the Delray) at the end of 1958. For 1959, Chevrolet's Brookwood would now offer a 2-door wagon and become the lowest priced station wagon. Chevrolet's two other wagon lines, the mid-range Brookwood and top-trimmed Nomad were available only as 4-door wagons for 1958. Chevrolet Big-Block engine#348 The Chevrolet "big-block" engine

2288-436: The 1970 racing season posted a best-of-season trap speed of 106.76 mph (172 km/h), which suggests something on the order of 350 "as installed" (SAE Net) HP for a 3,900 pounds (1,769 kg) car-and-driver combination. Indeed, Super Chevy Magazine conducted a chassis dyno test of a well-documented, well tuned, but stock 1970 LS-6 Chevelle and recorded 283 peak HP at the wheels – a figure that lines up quite well with

2376-594: The 396, 402, and 454 short-deck big-blocks. The 396 cu in (6.5 L) V8 was introduced in the 1965 Corvette as the L78 option and in the Z-16 Chevelle as the L37 option. It had a bore × stroke of 4.094 in × 3.760 in (104 mm × 95.5 mm), and produced 375 bhp (380 PS; 280 kW) at 5600 rpm and 415 lb⋅ft (563 N⋅m) of torque at 3600 rpm. The solid lifter version

2464-505: The 409 engine was announced along with the Impala SS (Super Sport) model. The initial version of the engine produced 360 hp (268 kW) with a single 4-barrel Carter AFB carburetor. The same engine was upped to 380 hp (283 kW) in 1962. A 409 hp (305 kW) version of this engine was also available, developing 1 hp per cubic inch with a dual four-barrel aluminum intake manifold and two Carter AFB carburetors. It had

2552-517: The GM Tonawanda Engine plant for auto production, and 20 partial engines were made for replacement/over-the-counter use. There is no evidence from GM that shows 57 cars were built. The so-called Mystery Motor, known internally as the Mark II or Mark IIS, is a race-only engine produced for the 1963 season. Development began with a 409 cu in (6.7 L) version (Mark II) and ended with

2640-573: The Italian Iso Grifo . This engine was identical to the 425 hp (317 kW) L72 427 (first introduced in 1966), but was fitted with 3×2-barrel Holley carburetors , known as " Tri-Power ," in lieu of the L72's single 4-barrel carburetor. Both engines used the same high-lift, long-duration, high-overlap camshaft and large-port, cast-iron heads to maximize cylinder head airflow (and, hence, engine power) at elevated engine-operating speeds. Consequently,

2728-406: The L72 and L71. In 2011, Super Chevy Magazine conducted a chassis dynamometer test of a well documented, production-line, stock but well-tuned L-72 "COPO" Camaro, and recorded a peak 287 hp (214 kW) at the rear wheels, demonstrating the substantial difference between 1960s-era SAE "gross" horsepower ratings and horsepower at the wheels on a chassis dynamometer. Wheel horsepower (which

Chevrolet Yeoman - Misplaced Pages Continue

2816-499: The LS-5 remained, when SAE net power ratings and the move towards emission compliance resulted in a temporary output decline, due to lowered compression, to about 270 hp (201 kW) and 468 lb⋅ft (635 N⋅m). The 1973 LS-4 produced 275 hp (205 kW) and 468 lb⋅ft (635 N⋅m), with 5 hp (4 kW) and 10 lb⋅ft (14 N⋅m) gone the following year. Hardened valve seats further increased reliability and helped allow these engines to last much longer than

2904-554: The MK III was a regular MK II design with a larger bore, but the Tonawanda plant didn't want to cast a block with a bore that large. The rumor that Packard's V8-engine tooling and production rights were considered for purchase by Chevrolet, was evidently true but never came to fruition. The Mark III was supposed to be a Mark II with bigger bore centers, but it never left the drawing board due to high tooling costs. The Mark IV differed from

2992-488: The W-series design were the race-proven Moraine M400 aluminum bearings first used in the 409, and the highly efficient "side oiling" lubrication system, which assured maximum oil flow to the main and connecting rod bearings at all times. Later blocks intended for performance use had the main oil gallery moved up to the cam bearing bore area and provided "priority main" oiling, improving the oil system even further. The 366 cu in (6.0 L) big-block V-8 gasoline engine

3080-400: The W-series engine in the placement of the valves and the shape of the combustion chambers. The chamber-in-block design of the W-series engine (which caused the power curve to drastically dip above 6500 rpm), was replaced by a more conventional wedge chamber in the cylinder head, which was now attached to a conventional 90 degree deck. The valves continued to use the displaced arrangement of

3168-474: The W-series engine were capable of operating at speeds well beyond 6000 rpm . The combustion chamber of the W-series engine was in the upper part of the cylinder , not the head, the head having only tiny recesses for the valves. This arrangement was achieved by combining a cylinder head deck that was not perpendicular to the bore with a crowned piston , which was a novel concept in American production engines of

3256-419: The W-series engine, but were also inclined so that they would open away from the combustion chamber and cylinder walls, a design feature made possible by Chevrolet's stud mounted rocker arms. This alteration in valve placement resulted in a significant improvement in volumetric efficiency at high RPM and a substantial increase in power output at racing speeds. Owing to the appearance of the compound angularity of

3344-539: The W-series engine. The cylinder block, although more substantial in all respects, used the same cylinder bore spacing of 4.84 in (123 mm) with a larger 2.75 in (70 mm) main bearing dimension, increased from the 2.5 in (63.5 mm) of the older engine. Like its predecessor, the Mark IV used crowned pistons, which were castings for conventional models and impact extruded ( forged ), solid skirt types in high performance applications. Also retained from

3432-413: The W-series was no longer needed, and wide, rectangular covers were used. In all forms (except the aluminum ZL-1), the Mark IV was slightly heavier than the W-series model, with a dry weight of about 685 lb (311 kg). Aside from the new cylinder head design and the reversion to a conventional 90 degree cylinder head deck angle, the Mark IV shared many dimensional and mechanical design features with

3520-577: The application. There were smooth running versions with hydraulic lifters suitable for powering the family station wagon , as well as rough-idling, high-revving solid lifter models usually applied to a minimally equipped, plain-looking, two-door Biscayne sedan fitted with the 425 hp (317 kW) version of the 427 (RPO L72 ). Perhaps the ultimate 427 for street applications was the 435 bhp (441 PS; 324 kW) at 5800 rpm and 460 lb⋅ft (624 N⋅m) at 4000 rpm of torque L71 version available in 1967 to 1969 Corvettes, and in

3608-507: The case with the similar L88. The then-staggering $ 4,718 cost of the ZL1 option doubled the price of the 1969 Corvette, resulting in just two production Corvettes (factory option at dealer) and 69 1969 Camaros (non-dealer option from factory – COPO 9560) being built with the ZL1. Chevrolet capitalized on the versatility of the 427 design by producing a wide variety of high-performance, "over-the-counter" engine components as well as ready-to-race "replacement" engines in shipping crates. Some of

Chevrolet Yeoman - Misplaced Pages Continue

3696-411: The components were developed to enhance the engine's reliability during high RPM operation, possibly justifying the use of the description "heavy duty." However, most of these items were racing parts originally designed for Can-Am competition that found their way onto dealers' shelves, and were meant to boost the engine's power output. Beginning in 1969, the highest performance 427 models were fitted with

3784-416: The cylinder. Use of automatic valves simplified the mechanism, but valve float limited the speed at which the engine could run, and by about 1905 mechanically operated inlet valves were increasingly adopted for vehicle engines. Mechanical operation is usually by pressing on the end of the valve stem, with a spring generally being used to return the valve to the closed position. At high engine speeds ( RPM ),

3872-429: The day. As the piston approached top dead center , the angle of the crown combined with that of the head deck to form a wedge-shaped combustion chamber with a pronounced quench area. The spark plugs were inserted vertically into the quench area, which helped to produce a rapidly moving flame front for more complete combustion. The theory behind this sort of arrangement is that maximum brake mean effective pressure (BMEP)

3960-562: The drawing board. The big-block, which debuted in 1958 at 348  cu in (5.7  L ), was built in standard displacements up to 496 cu in (8.1 L), with aftermarket crate engines sold by Chevrolet exceeding 500 cu in (8.2 L). The first version of the "big-block" V8 Chevrolet engine, known as the W-series, was introduced in 1958. Chevrolet designed this engine for use in passenger cars and light trucks. This engine had an overhead valve design with offset valves and uniquely scalloped valve covers , giving it

4048-516: The earlier versions, even without the protection previously provided by leaded fuel . 1974 was the last year of the 454 in the Corvette, although the Chevelle offered it in the first half of the 1975 model year. It was also available in the full size Impala/Caprice through model year 1976. General Motors introduced EFI in 1987, which was found on GM C1500 SS, C/K2500, and C/K3500 trucks. The 454 EFI version

4136-400: The engines offered very similar performance and resulted in a car whose performance was described by one automotive journalist as "the ultimate in sheer neck-snapping overkill". Typical 2000s-era magazine road tests of Corvettes with the engine yielded 0-60 mph (97 km/h) in 5.6 seconds and 1 ⁄ 4 mile (402 m) in 13.8 second at 104 mph (167 km/h) range for both

4224-468: The exhaust valve remains beside the cylinder in an upside down orientation. These designs were largely replaced by the overhead valve (OHV) engine between 1904 until late-1960s/early-to-mid 1970s, whereby the intake and exhaust valves are both located directly above the cylinder (with the camshaft located at the bottom of the engine). In turn, OHV engines were largely replaced by the overhead camshaft (OHC) engines between 1950s until 1980s. The location of

4312-401: The force required to open them. This has led to the development of the balanced poppet or double beat valve , in which two valve plugs ride on a common stem, with the pressure on one plug largely balancing the pressure on the other. In these valves, the force needed to open the valve is determined by the pressure and the difference between the areas of the two valve openings. Sickels patented

4400-421: The foundry must retool every time a compression change is in order. The necessity of making special heads to provide a range of compression ratios and to permit attachment of accessory mountings for the various model applications is of serious concern to the manufacturing and service departments ... Inclining the top of the block to 16° and shaping the top of the piston like a gabled roof with a 16° angle resulted in

4488-416: The frame adopted for the 1957 Cadillac, it featured box-section side rails and a boxed front cross member that bowed under the engine, these "x-frames" were used on other 1958 to 1964 Chevys, as well as Cadillac. The rear was tied together by a channel-section cross member. This design was later criticized as providing less protection in the event of a side impact collision, but would persevere until 1965. Of

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4576-410: The high performance 409 and 427 engines had larger ports and valves than those used on the 348 and the base 409 passenger car and truck engines, but externally were identical to the standard units – but for the location of the engine oil dipstick, on the driver's side on the 348 and the passenger's on the 409/427. No satisfactory explanation was ever offered for why this change was made, but it did provide

4664-409: The hot valve head to the stem where it may be conducted to the cylinder head. Common in second world war piston engines, now only found in high performance engines. Early engines in the 1890s and 1900s used an "automatic" intake valve, which was opened by the vacuum in the combustion chamber and closed by a light spring. The exhaust valve had to be mechanically driven to open it against the pressure in

4752-500: The later, second-generation 427, it was based on the W-series 409 engine, but with a longer 3.65 in (92.7 mm) stroke. A high-rise, two-piece aluminum intake manifold and dual Carter AFB carburetors fed a 13.5:1 compression ratio to produce an under-rated SAE gross 430 hp (321 kW) and 575 lb⋅ft (780 N⋅m). Fifty RPO Z11 cars were produced at the Flint GM plant . Extant GM Documents show 50 Z11 engines were built at

4840-408: The main oil galley was moved from near the oil pan to near the camshaft. Also the valvetrain became non-adjustable and the provisions for a mechanical fuel pump were eliminated. Cast aluminum valve covers were fitted in place of stamped steel covers, featuring a screw-in filler cap. Structural changes were carried out to the cylinder case to improve the integrity of the bores and the inlet manifold

4928-461: The necessary accessories and drive system to adapt them to marine propulsion. Mercury Marine , in particular, was a major user of the Mark IV in marine drives, and relabeled the engines with their corporate logo. For 1991, General Motors made significant changes to the big-block resulting in the Generation V. The block received a one-piece rear seal and all blocks received 4-bolt mains. Additionally

5016-450: The new open (vs. closed) chamber cylinder heads, along with design improvements in crankshafts, connecting rods, and pistons, adopted from the Can-Am development program. Chevrolet gave all 427 engines except the ZL1 a torque rating of 460 lb⋅ft (624 N⋅m). Applications: 427 production codes: For 1970, the big-block was expanded again, to 454 cu in (7.4 L), with

5104-412: The number 13 car, driven by Johnny Rutherford , finished four laps down (in ninth place), with the top five cars being the heavier 1963 Ford Galaxie 500's. This "secret" engine was a unique design incorporating aspects of both the W-series and the mid-1965 introduced Mark IV, referred to in sales literature as the "Turbo-Jet V8". Richard Keinath, the original Mark II and IV design engineer stated that

5192-586: The open combustion chamber aluminum heads finally were in production and began being fitted to the L88 and ZL1 engines. The ZL1 engine also featured a lightweight aluminum water pump, a camshaft that was slightly "hotter" than the L88's, and a specially tuned aluminum intake manifold. Like the L88, the ZL1 required 103 octane (RON) (minimum) fuel (102 octane RON [Sunoco 260] represented the highest octane gasoline sold at common retail stations), used an unshrouded radiator, and had poor low-speed idle qualities – all of which made

5280-547: The plane of the port. The main advantage of the poppet valve is that it has no movement on the seat, thus requiring no lubrication. In most cases it is beneficial to have a "balanced poppet" in a direct-acting valve. Less force is needed to move the poppet because all forces on the poppet are nullified by equal and opposite forces. The solenoid coil has to counteract only the spring force. Poppet valves are best known for their use in internal combustion and steam engines, but are used in general pneumatic and hydraulic circuits where

5368-544: The poppet valve which sits inside the combustion chamber is a flat disk, while the other side tapers from the disk shape to a thin cylindrical rod called a "valve stem". In a typical modern mass-production engines, the valves are solid and made from steel alloys . However some engines use hollow valves filled with sodium , to improve heat transfer . Many modern engines use an aluminium cylinder head. Although this provides better heat transfer, it requires steel valve seat inserts to be used; in older cast iron cylinder heads,

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5456-404: The poppet valve, move bodily in response to remote motion transmitted linearly. In the past, "puppet valve" was a synonym for poppet valve ; however, this usage of "puppet" is now obsolete. The poppet valve is different from both slide and oscillating valves. Instead of sliding or rocking over a seat to uncover a port, the poppet valve lifts from the seat with a movement perpendicular to

5544-450: The previously referenced 350 SAE Net HP figure. An even more powerful version, producing 465 hp (347 kW) and 610 lb⋅ft (827 N⋅m), of the 454, then dubbed LS-7 (not to be confused with the modern, mid 2000s, 7-litre Chevrolet Corvette engine that powered the C6 Z06, which is an LS7). Several LS-7 intake manifolds were individually produced and sold to the general public by

5632-422: The previously referenced 376 hp (280 kW) SAE Net figure. Super Stock and Drag Racing Magazine recorded an 11.62 second/122.15 mph (196.58 km/h) 1 ⁄ 4 mile (402 m) in a professionally tuned ZL1 Camaro with open long-tube S&S equal-length headers, drag slicks, and minor suspension modifications, driven by drag racing legend Dick Harrell. Using Patrick Hale's Power/Speed formula,

5720-484: The smaller cars while at the same time labeling it "Turbo-Jet 400" in the full-size cars. Power rating(s) by year: Applications: 396 and 402 production codes: The highly successful and versatile 427 cu in (7.0 L) version of the Mark IV engine was introduced in 1966 as a production engine option for full-sized Chevrolets and Corvettes. The bore was increased to 4 + 1 ⁄ 4  in (108 mm), with power ratings varying widely depending on

5808-449: The throttle is abruptly closed. Historically, valves had two major issues, both of which have been solved by improvements in modern metallurgy . The first was that in early internal combustion engines, high wear rates of valves meant that a valve job to regrind the valves was required at regular intervals. Secondly, lead additives had been used in petrol (gasoline) since the 1920s, to prevent engine knocking and provide lubrication for

5896-417: The torpedo from the tube , and the poppet valve recovers a large quantity of this air (along with a significant amount of seawater) in order to reduce the tell-tale cloud of bubbles that might otherwise betray the boat's submerged position. Poppet valves are used in most piston engines to control the flow of intake and exhaust gasses through the cylinder head and into the combustion chamber . The side of

5984-432: The twisting path of the intake and exhaust gasses had major drawbacks for the airflow, which limited engine RPM and could cause the engine block to overheat under sustained heavy load. The flathead design evolved into intake over exhaust (IOE) engine , used in many early motorcycles and several cars. In an IOE engine, the intake valves were located directly above the cylinder (like the later overhead valve engines ), however

6072-464: The two engines largely unsuitable for street use. As impressive as the ZL1 was in its day, actual engine dyno tests of a certified production line stock ZL1 revealed 376 hp (280 kW) SAE net with rated output swelling to 524 hp (391 kW) SAE gross with the help of optimal carb and ignition tuning, open long tube racing headers, and with no power-sapping engine accessories or air cleaner in place. A second engine dyno test conducted on

6160-410: The type of intake manifold and carburetion systems present. It was 1.5 inches longer, 2.6 inches wider, and 0.84 inches shorter than the 283 "small-block". General Motors engineers explained, in 1959, reasons behind the combustion-in-block setup. Anticipating varied future compression ratios in future auto and truck use: "It was obvious that with the combustion chamber placed within the cylinder head,

6248-466: The valve seats are often part of the cylinder head. A gap of 0.4–0.6 mm (0.016–0.024 in) is present around the valve stem, therefore a valve stem oil seal is used to prevent oil being drawn into the intake manifold and combustion chamber. Typically, a rubber lip-type seal is used. A common symptom of worn valve guides and/or defective oil seals is a puff of blue smoke from the exhaust pipe at times of increased intake manifold vacuum , such as when

6336-466: The valves is broadly the same between OHV and OHC engines, however OHC engines saw the camshaft located to the top of the engine with the valves and OHC engines often have more valves per cylinder. Most OHC engines have an extra intake and an extra exhaust valve per cylinder (four-valve cylinder head), compared with the design of two valves per cylinder used by most OHV engines. However some OHC engines have used three or five valves per cylinder. James Watt

6424-435: The valves, the automotive press dubbed the engine the "porcupine" design. As part of the head redesign, the spark plugs were relocated so that they entered the combustion chamber at an angle relative to the cylinder centerline, rather than the straight-in relationship of the W-series engine. This too helped high RPM performance. Due to the new spark plug angle, the clearance provided by the distinctive scalloped valve covers of

6512-454: The valves, via several intermediate mechanisms (such as pushrods , roller rockers and valve lifters ). The shape of the cams on the camshaft influence the valve lift and determine the timing of when the valves open. Early flathead engines (also called L-head engines ) saw the valves located beside to the cylinder(s), in an "upside down" orientation parallel to the cylinder. Although this design made for simplified and cheap construction,

6600-462: The valves. Modern materials for the valves (such as stainless steel) and valve seats (such as stellite ) allowed for leaded petrol to be phased out in many industrialised countries by the mid-1990s. Exhaust valves are subject to very high temperatures and in extreme high performance applications may be sodium cooled. The valve is hollow and filled with sodium, which melts at a relatively low temperature and, in its liquid state, convects heat away from

6688-445: The vehicle became as the premium four-door Chevrolet station wagon , rather than the two-door designs of the 1955-57 Nomads. A new dash was used. The value of a drag coefficient for 1958 Chevy wagons is estimated by a-c, is Cd = 0.6. The Delray-based Yeoman was the lowest version and featured minimal interior and exterior trim and limited options. The Yeoman featured Chevrolet's new "Safety-Girder" cruciform frame. Similar in layout to

6776-405: The weight of the valvetrain means the valve spring cannot close the valve as quickly enough, leading to valve float or valve bounce . Desmodromic valves use a second rocker arm to mechanically close the valves (instead of using valve springs) and are sometimes used to avoid valve float in engines that operate at high RPM. In most mass-produced engines, the camshaft (s) control the opening of

6864-534: Was a broad grille and quad headlights that helped simulate a 'Baby Cadillac'; the wagon's tail received a fan-shaped alcove on both side panels, similar to the sedan's, but wagons housed single tail lights instead of dual (triple on Impala) to accommodate the tailgate. Despite being a recession year, sales increased and overtook Ford, which held the top position in 1957) and the Bel Air the most popular Chevrolet model. The Nomad station wagon name also reappeared in 1958 when

6952-634: Was achieved by a simple sliding camshaft system. Many locomotives in France, particularly those rebuilt to the designs of Andre Chapelon, such as the SNCF 240P , used Lentz oscillating-cam poppet valves, which were operated by the Walschaert valve gear the locomotives were already equipped with. The poppet valve was also used on the American Pennsylvania Railroad 's T1 duplex locomotives , although

7040-484: Was again increased to 340 hp (254 kW) for the single four-barrel model, and 338 hp (252 kW) when equipped with Tri power. A 409 cu in (6.7 L) version was Chevrolet's top regular production engine from 1961 to 1965, with a choice of single or 2X4-barrel Rochester carburetors . Bore x stroke were both up from the 348 cu in (5.7 L) to 4.31 in × 3.5 in (109.5 mm × 88.9 mm). On December 17, 1960,

7128-493: Was an L71 fitted with aluminum heads. While this option produced no power advantage, it did reduce engine (and hence, vehicle) weight by roughly 75 pounds (34 kg). Although the difference in straight line performance was negligible, the weight savings resulted in superior vehicle weight distribution and improved handling and braking. The all-aluminum 1969 ZL1 version of the 427 engine was developed primarily for Can-Am racing, which did not require homologation to compete,; it

7216-408: Was capable of being operated in the upper 6000 rpm range, and when installed in the 1965 Corvette, was factory-rated at 425 hp (317 kW). Introduced in 1970, the 402 cu in (6.6 L) was a 396 cu in (6.5 L) bored out by 0.03 in (0.76 mm). Despite being 6 cubic inches (98 cc) larger, Chevrolet continued marketing it under the popular "396" label in

7304-533: Was changed to a single-piece design. The 366 cu in (6.0 L) truck engine also received the Mark V updates for 1991. From 1991, the 454 was updated to the new Gen V block, crankshaft and heads. This engine was rated at 230 net hp, 380 lb-ft net torque, and was discontinued after 1995, with GM coming out with the Vortec 7400 in 1996. Poppet valve A poppet valve (also sometimes called mushroom valve )

7392-421: Was rated from 230 hp (172 kW) to 255 hp (190 kW) and from 385 lb⋅ft (522 N⋅m) to 405 lb⋅ft (549 N⋅m) of torque. The 1991–1993 454SS made 255 horsepower at 4000 rpm and 405 lb-ft of torque at 2400 rpm thanks to dual 2.5" catalytic converters. All other versions, including the 1990 SS, made 230 horsepower at 3600 rpm and 385 lb-ft of torque at 1600 rpm through

7480-408: Was replaced by the 396 cu in (6.5 L) 375 hp (280 kW) Mark IV big-block engine. In addition, a 340 hp (254 kW) version of the 409 engine was available from 1963 to 1965, with a single 4-barrel cast iron intake mounting a Rochester 4GC square-bore carburetor, and a hydraulic-lifter camshaft. A special 427-cubic-inch (7.0 L) version of the 409 engine was used in

7568-402: Was used in Chevrolet medium duty trucks and school buses. It had a bore and a stroke of 3.935 in × 3.76 in (99.9 mm × 95.5 mm). This engine was made from the 1960s until 2004.The 366 used 4 rings on the pistons, as it was designed from the very beginning as a truck engine. The 366 was produced only as a tall-deck engine, with a deck 0.4 in (10 mm) taller than

7656-528: Was using poppet valves to control the flow of steam into the cylinders of his beam engines in the 1770s. A sectional illustration of Watt's beam engine of 1774 using the device is found in Thurston 1878:98, and Lardner (1840) provides an illustrated description of Watt's use of the poppet valve. When used in high-pressure applications, for example, as admission valves on steam engines, the same pressure that helps seal poppet valves also contributes significantly to

7744-576: Was very successful in cars like the McLaren M8B . The ZL1 specifications were nearly identical to the production L88 version of the 427, but featured an aluminum block in addition to aluminum cylinder heads. The first Corvette with the RPO ZL1 engine package was built in early December 1968 and featured aluminum closed chamber heads shared with the L88. Both L88 and ZL1 optioned cars continued to be built with closed chamber heads until approximately March 1969, when

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