FUTURESTRADER
07-28-2004, 04:13 PM
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FOR RELEASE: 2004-07-28
GM Powertrain Opens Performance Build Center
GM Powertrain inaugurates $10 million Performance Build Center to produce hand-built high-performance engines. First engine produced: LS7 V-8, beginning second-quarter 2005 Vortec 6000 6.0-liter all-aluminum V-8 (LS2), fourth generation of GM's hallowed small-block design, will be available in the 2005 Chevrolet SSR Fifty years of small-block heritage commemorated with launch of LS2 and exhibit area at Performance Build Center
DETROIT - General Motors Corp. is adding more muscle to its claim of "World's Best Powertrains" with the official opening of its Performance Build Center, a $10 million facility dedicated to building high-performance engines for low-volume, premium vehicles.
The first hand-built engine variant to come from the Performance Build Center will be the LS7 OHV V-8 that is the heart of the Z06 performance package earmarked for the 2006 Corvette; specifications and details for the LS7 will be provided at the 2005 North American International Auto Show.
Another variant of GM Powertrain's newly revised small-block engine family, the Vortec 6000 6.0-liter V-8 (LS2), powers the 2005 Chevrolet SSR. It is an all-aluminum version of the new fourth generation of GM's timeless small-block V-8. The Gen IV design comprises the latest series of technical revisions to the engine.
The new Gen IV small-block V-8 also will launch in several 2005 GM SUVs. Those trucks will use Gen IV V-8s with cast aluminum cylinder blocks and feature GM Powertrain's efficiency enhancing Displacement on Demand cylinder deactivation technology.
The 2005 launch of the Gen IV also marks the 50th anniversary of the small-block's launch in the '55 Chevrolet lineup. The Gen IV variant makes the small-block one of the most enduring designs of any mass-producing industrial sector.
Performance Build Center
The GM Powertrain Performance Build Center, a 100,000 square foot facility in the Detroit suburb of Wixom, is the culmination of former GM Powertrain Vice President Ned McClurg's vision to see the company's Powertrain division - the world's highest-volume producer of automotive engines - establish a reputation as a builder of hand-crafted, high-performance "niche" engines for low-volume specialty vehicles.
"Ned saw a strong market niche GM had not gone after in the past," said Timothy M. Schag, site manager for the Performance Build Center. The idea went to the highest levels of the corporation - but ultimately needed little selling. GM executives and planners already had foreseen the need to compete with other automakers crafting high-performance "image powertrains" for premium vehicles, said Schag.
Schag, a GM engineer with decades of powertrain manufacturing and engineering experience, traveled the world with other Powertrain engineers to study competitive niche-engine building facilities and benchmark race teams' operations.
The Performance Build Center will combine the best practices of contemporary niche-engine construction with the volume-manufacturing system that has enabled GM Powertrain to claim leadership in a string of recent J.D. Power and Associates rankings of manufacturing quality. Schag says, in fact, that while the Performance Build Center's volumes may be purposely small - capacity is 15,000 engines annually - all of the quality standards that apply to every GM Powertrain manufacturing facility will be fully in place. The facility will achieve TS 16949 certification by the end of the year and the site will be compatible with GM Global Manufacturing System processes.
Engines built at the Performance Build Center will be constructed by specially trained craftspeople from United Auto Workers Local 653, based in Pontiac, Mich. Each technician on the 80-person force receives extensive high-level instruction - every technician has built complete engines before.
This philosophy of craftsmanship and "ownership" is the crux of the Performance Build Center's philosophy. One technician will build a complete engine from start to finish. The Performance Build Center's highly flexible manufacturing concept and tooling, combined with technicians' ability to assemble any engine, mean that throughput of different engines can be quickly adjusted to address shifting market demand.
The Performance Build Center will be the focal point of GM's goal to make expressive and emotional vehicles, with powertrains that match that excitement. "It's a much more efficient way to get these special, high-performance engines to the street," said Schag.
The LS7 OHV V-8 for 2006 Chevrolet Corvette ZO6 is the first engine confirmed for the Performance Build Center, but others will follow.
"Performance means different things to different people. Sometimes it's pure horsepower. Maybe it's sophistication. Whatever the definition, this facility will deliver world-class engines," Said Schag.
Performance Build Center Fast Facts
A $10 million, 100,000 sq. ft. facility in Wixom, Mich.
First product: Gen IV LS7 small-block V-8 for 2006 Chevrolet Corvette Z06
Specially trained technicians from UAW Local 653; each technician builds an engine from start to finish
Capacity: 15,000 engines annually; highly flexible "mix" can respond to quickly changing market conditions
Every engine to be hot-tested
SSR's Vortec 6000 6.0-liter ushers in fourth generation of small-block V-8
The new Gen IV Vortec 6000 6.0-liter V-8 (LS2) small block injects a new level of performance for the 2005 Chevrolet SSR.
Also new for 2005, the Gen IV Vortec 5300 5.3-liter small-block V-8 will feature GM Powertrain's Displacement on Demand cylinder deactivation to be rolled out in various 2005-model GM SUVs. In all applications, the Gen IV is revised in several key areas to enhance efficiency and durability, reduce friction and improve airflow.
For the 2005 SSR, the Vortec 6000 6.0-liter Gen IV small-block develops 390 hp at 5400 rpm and 405 lb.-ft. of torque at 4400 rpm. The SSR's Vortec 6000 6.0-liter LS2 is backed by a standard Hydra-Matic 4L65-E four-speed automatic transmission, or new for 2005, a Tremec M10 six-speed manual.
Numerous revisions, updates and improvements comprise the new Gen IV small-block V-8. "The new Gen IV engine is the best example yet of the continuous refinement in performance and efficiency that has been part of the small-block's legacy since day one," said Dan Nicholson, chief engineer of small-blocks.
A summary of new or changed components for the Gen IV architecture:
Larger 90-mm throttle body: The 6.0-liter displacement requires a higher volume of intake air; the Gen III throttle body is 75 mm. The new throttle body is mounted to a revised-design composite intake manifold with tuned runners to optimize airflow to individual cylinders.
New combustion-chamber design: Understanding of the flow characteristics in the highly tuned LS6 small-block were applied to the new Gen IV combustion chambers. The result is higher power output and increased volumetric efficiency.
Higher compression ratio: Hand-in-hand with Gen IV's new combustion chamber design is the ability to increase compression ratio to 10.9:1 compared to the 10:1 of the High-Output Vortec 6.0-liter Gen III V-8.
High-lift cam profile: Intake breathing is enhanced with a new, higher-lift camshaft. Also fitted are stronger valve springs to enable a higher peak-rpm range.
Flat-top pistons and stronger floating wrist pins: Floating piston wrist pins enhance durability, while engine testing and computer modeling demonstrated flat-top pistons generate the best power.
Compact, lighter water pump: All Gen IV V-8s are fitted with a more compact, more efficient water pump that reduces mass, conserves underhood space and reduces parasitic losses.
Deeper oil pan: The LS2 truck engine is designed with a deeper oil sump than the LS2 passenger-car engine. The new oil pan also incorporates a pass-through for a front driveshaft when used in four-wheel-drive applications.
Reduced-tension piston rings: Piston rings are a new, lower-tension design to reduce friction.
Redesigned crankcase vent: The crankcase vent is repositioned to the top of the block valley, where oil is less likely to enter during high engine speeds or high-g maneuvers.
New accessory-drive package: A new power steering pump and revised serpentine drive belt result in better space utilization.
Along with the increased power and torque when compared to the Gen III High Output Vortec 6.0-liter V-8, the new Gen IV Vortec 6000 6.0-liter continues GM Powertrain's ongoing commitment to reducing maintenance intervals and servicing costs.
Dexcool coolant and the platinum-tipped spark plugs have 100,000-mile change intervals. An Oil Life System function, built directly into the engine control module, calculates ideal oil-change intervals based on a variety of performance parameters.
Gen IV Vortec 6000 6.0-liter V-8 Fast Facts
First truck application: 2005 Chevrolet SSR
First small-block V-8 for truck applications to use aluminum cylinder block
390 hp (291 kW) at 5400 rpm
405 lb.-ft. (542 Nm) of torque at 4400 rpm
Numerous internal revisions enhance power as well as improve efficiency
GM Powertrain marks 50 years of small-block heritage
GM Powertrain is introducing its new Gen IV small-block V-8 architecture for several 2005 model GM vehicles exactly 50 years after the original small-block was launched for Chevrolet in 1955. One of any engine family's most important design elements - the distance between bore centers - remains the same 4.4 inches for today's new Gen IV as it was in Chevrolet Chief Engineer Ed Cole's seminal initial design.
Compact, powerful and packed with innovative technology: it's an accurate description of the new Gen IV V-8, and those same words were used to describe the original small-block in 1955.
In addition to its new, all-aluminum 6.0-liter variant for car and truck applications (LS2), the Gen IV architecture will be launched in V-8-equipped models of the 2005 Chevrolet TrailBlazer EXT, GMC Envoy XL and Envoy XUV, offering fuel-saving Displacement on Demand (DOD) technology.
"The small-block V-8 not only is a viable and relevant engine in today's market, but technology such as Displacement on Demand demonstrates its adaptability in the face of evolving marketplace expectations," said Dan Nicholson, chief engineer of small-blocks.
DOD has the capability to disable the combustion process of half the engine's cylinders in certain driving conditions, enabling fuel savings of up to 8 percent. The process is instantaneous and virtually imperceptible, and the engine delivers horsepower and torque bands comparable to previous non-DOD small-block engines.
The first passenger-car version of the Gen IV V-8 - without DOD - debuts in the 2005 Chevrolet Corvette.
GM Powertrain estimates that by the end of the 2005 model year, more than 90 million small-block-based engines will have been produced since the original engine's 1955 introduction.
Compact design the heart of small-block advantage
Contemporary demands for efficiency and performance refinements were the very demands that pushed the original small-block's development 50 years ago. It started in the early '50s with the planned replacement of Chevy's sturdy, but antiquated, straight-six engine - a large, heavy powerplant commonly called the Stovebolt Six.
Although a new V-8 was on the drawing table when Chief Engineer Ed Cole transferred from Cadillac to Chevrolet in 1952, he soon dismissed the original design and challenged his engineers to develop a more compact engine that would be easier to manufacture. The overhead valve design had been a staple of the Stovebolt engine and, to some at GM, one of the Chevrolet cars' selling points. Retaining that trait was agreeable with Cole, whose previous assignment was the design of Cadillac's OHV V-8.
When completed, the new V-8 engine had a minimalist design to take advantage of streamlined production techniques. Innovations like green-sand casting, which allowed the block to be cast upside down and dramatically reduce the number of cores, as well as lightweight stamped-steel rocker arms that allowed a much higher rpm range, were state-of-the-art.
The new small-block's cylinder heads were another important step forward. Their cross-flow port design and wedge-shape combustion chambers were very efficient and, when combined with the high rpm capability of the valvetrain, gave the new V-8 a broad performance band. Also, the engine's quintet of head bolts around each cylinder provided superior cylinder head location. Other innovations included:
Hollow pushrods to transfer lubricating oil to the cylinder heads
A single-piece intake manifold combined the water outlet, exhaust heat riser, distributor mounting and lifter valley cover in a single component
Internal lubrication eliminated the need for external oil lines, greatly reducing the chance for leaks
Compact size required less iron to produce the engine and less water to cool it during operation.
The internal oiling system was a breakthrough not found on many other automotive engines at the time, especially in Chevrolet's low-price field.
And though a seemingly inconsequential specification at the time, the new small-block engine also was designed with 4.4-inch bore centers - the distance from the center of one cylinder to the next. The design contributed to the engine's compact size, but the dimension has come to symbolize the balanced harmony of the small block. It was the dimension around which the all-new Gen III small block was designed in 1997.
"The long history of the small-block is one of the reasons the new generation of engines is so powerful and efficient," said Nicholson. "GM has almost 50 years of experience with its valve-in-head design, and that has provided immeasurable detail for keeping the small-block a viable, relevant engine for today and the future."
A legacy of power and adaptability
With 3.75-inch bores and a 3.00-inch stroke, the first small-block displaced just 265 cubic inches (4.35 liters). Drawing its breath through a two-barrel carburetor, the base version produced 162 horsepower (gross); with a four-barrel, the engine was rated at 195 (gross) in the Corvette. Better still, it weighed nearly 50 pounds less than the old Stovebolt Six.
From that auspicious beginning, the small-block was at the forefront of technology. A fuel-injected version of the engine was available from 1957 through the mid-‘60s, and as the horsepower wars of the late Sixties raged, the small-block proved to be powerful ammunition for Chevrolet.
The small-block would grow to a maximum of 400 cubic inches and, with the 2004 Corvette Z06's LS6 engine, produce 405 horsepower. In less glamorous, but perhaps more important roles, small-blocks reliably powered millions of family cars and work trucks.
When marketplace demands required more efficiency, the small-block was downsized to accommodate. But as engineers found new and better ways to extract power from the venerable engine, the small-block's displacement and power increased while meeting - or exceeding - federal requirements for fuel efficiency and lowered emissions.
In the early ‘90s, the Gen II small-block was introduced in high-performance cars including the Corvette and Pontiac Firebird Trans Am. Known as the LT1 and, later, the LT4, the Gen II featured new, low-friction internal components and reverse-flow cooling to enable the most powerful small-blocks since the heyday of the muscle car era. Some Gen II features, including the low-profile, high-flow, intake manifold previewed technology that would be incorporated into the all-new Gen III.
The Gen III was introduced as the LS1 5.7-liter engine in the 1997 Corvette, while Vortec versions of the Gen III for trucks were introduced in 1999, with displacements ranging from 4.8 liters to 6.0 liters. The Gen III engine benefited from new technology and production methods, but its design drew upon more than 40 years of research and continuous improvements from the Gen I and Gen II small-blocks.
Continual improvements also drove the development of new efficiencies and power increases in the Gen IV small-block.
Milestones
The legacy of the small-block has left an indelible mark on the global auto industry and American automotive culture. Some of its many noteworthy milestones include:
1955: Small-block V-8 introduced in 1955 Chevrolets.
1957: Larger bore increased displacement to 283 cubic inches (4.6 liters); Ramjet mechanical fuel injection was introduced, bringing horsepower to 283 - one horsepower for every cubic inch.
1962: Displacement increased to 327 cubic inches (5.4 liters), with Ramjet fuel injected version rated at 360 horsepower.
1964: Cylinder head improvements bump the 327's highest horsepower rating to 375 with fuel injection.
1967: Little-known option Z28 released for the Camaro, which includes a high-revving 302-cubic-inch (4.9-liter) small-block for competition in SCCA Trans Am road racing.
1968: A Camaro Z28 wins the Trans Am championship; a 350-cubic-inch (5.7 liters) version of the small-block debuts and would become the quintessential small-block variant.
1970: 350-cubic-inch LT1 debuts in Camaro and Corvette and is rated at 370 horsepower; 400-cubic-inch (6.6-liter) small-block is offered - the largest-displacement small-block built.
1975: With fuel economy prevalent in consumers' minds, a more efficient 262-cubic-inch (4.3-liter) small-block is introduced.
1978: V-6 engine based on small-block design introduced; it would become the Vortec V-6 truck engine more than a decade later.
1980: Last year for the 400 small block.
1982: Fuel injection reintroduced with the Cross-Fire injection system on Corvette and the redesigned Camaro Z28.
1985: Tuned port fuel injection replaces Cross-Fire Injection, ushering in the modern era of electronically controlled, port-injected engines.
1986: Aluminum cylinder heads debut as standard equipment on Corvette; block changed to accept new single-piece rear main seal.
1987: Hydraulic roller lifters introduced.
1989: The H.O. 350 "crate engine" is developed, offering a ready-built performance engine from the factory. It would change the way hot rodders approach engine building in the next decade.
1992: LT1 engine in the Corvette introduces Gen II small block design, which features reverse-flow cooling, revised cylinder head design, and crank-triggered optical distributor.
1996: Vortec V-8 engines introduced in trucks, featuring cylinder heads with swirl-inducing combustion chamber design to increase power and torque.
1997: Gen III 5.7-liter LS1 small-block introduced with all-new Corvette, featuring all-new deep-skirt block casting with six-bolt mains; redesigned cylinder heads with symmetrical ports and combustion chambers; and coil-near-plug ignition system.
1999: Gen III-based Vortec V-8 engines introduced in GM trucks; displacements include 4.8 liters, 5.3 liters and 6.0 liters.
2005: Gen IV small-block introduced 50 years after the original.
More than power or displacement, the significance of the small-block has been its adaptability as market demands and technology evolved during the past five decades. Engineers have met every challenge and kept the small-block on the leading edge of performance.
The introduction of the Gen IV engine signals the small-block's legacy will extend for decades to come.
FOR RELEASE: 2004-07-28
GM Powertrain Opens Performance Build Center
GM Powertrain inaugurates $10 million Performance Build Center to produce hand-built high-performance engines. First engine produced: LS7 V-8, beginning second-quarter 2005 Vortec 6000 6.0-liter all-aluminum V-8 (LS2), fourth generation of GM's hallowed small-block design, will be available in the 2005 Chevrolet SSR Fifty years of small-block heritage commemorated with launch of LS2 and exhibit area at Performance Build Center
DETROIT - General Motors Corp. is adding more muscle to its claim of "World's Best Powertrains" with the official opening of its Performance Build Center, a $10 million facility dedicated to building high-performance engines for low-volume, premium vehicles.
The first hand-built engine variant to come from the Performance Build Center will be the LS7 OHV V-8 that is the heart of the Z06 performance package earmarked for the 2006 Corvette; specifications and details for the LS7 will be provided at the 2005 North American International Auto Show.
Another variant of GM Powertrain's newly revised small-block engine family, the Vortec 6000 6.0-liter V-8 (LS2), powers the 2005 Chevrolet SSR. It is an all-aluminum version of the new fourth generation of GM's timeless small-block V-8. The Gen IV design comprises the latest series of technical revisions to the engine.
The new Gen IV small-block V-8 also will launch in several 2005 GM SUVs. Those trucks will use Gen IV V-8s with cast aluminum cylinder blocks and feature GM Powertrain's efficiency enhancing Displacement on Demand cylinder deactivation technology.
The 2005 launch of the Gen IV also marks the 50th anniversary of the small-block's launch in the '55 Chevrolet lineup. The Gen IV variant makes the small-block one of the most enduring designs of any mass-producing industrial sector.
Performance Build Center
The GM Powertrain Performance Build Center, a 100,000 square foot facility in the Detroit suburb of Wixom, is the culmination of former GM Powertrain Vice President Ned McClurg's vision to see the company's Powertrain division - the world's highest-volume producer of automotive engines - establish a reputation as a builder of hand-crafted, high-performance "niche" engines for low-volume specialty vehicles.
"Ned saw a strong market niche GM had not gone after in the past," said Timothy M. Schag, site manager for the Performance Build Center. The idea went to the highest levels of the corporation - but ultimately needed little selling. GM executives and planners already had foreseen the need to compete with other automakers crafting high-performance "image powertrains" for premium vehicles, said Schag.
Schag, a GM engineer with decades of powertrain manufacturing and engineering experience, traveled the world with other Powertrain engineers to study competitive niche-engine building facilities and benchmark race teams' operations.
The Performance Build Center will combine the best practices of contemporary niche-engine construction with the volume-manufacturing system that has enabled GM Powertrain to claim leadership in a string of recent J.D. Power and Associates rankings of manufacturing quality. Schag says, in fact, that while the Performance Build Center's volumes may be purposely small - capacity is 15,000 engines annually - all of the quality standards that apply to every GM Powertrain manufacturing facility will be fully in place. The facility will achieve TS 16949 certification by the end of the year and the site will be compatible with GM Global Manufacturing System processes.
Engines built at the Performance Build Center will be constructed by specially trained craftspeople from United Auto Workers Local 653, based in Pontiac, Mich. Each technician on the 80-person force receives extensive high-level instruction - every technician has built complete engines before.
This philosophy of craftsmanship and "ownership" is the crux of the Performance Build Center's philosophy. One technician will build a complete engine from start to finish. The Performance Build Center's highly flexible manufacturing concept and tooling, combined with technicians' ability to assemble any engine, mean that throughput of different engines can be quickly adjusted to address shifting market demand.
The Performance Build Center will be the focal point of GM's goal to make expressive and emotional vehicles, with powertrains that match that excitement. "It's a much more efficient way to get these special, high-performance engines to the street," said Schag.
The LS7 OHV V-8 for 2006 Chevrolet Corvette ZO6 is the first engine confirmed for the Performance Build Center, but others will follow.
"Performance means different things to different people. Sometimes it's pure horsepower. Maybe it's sophistication. Whatever the definition, this facility will deliver world-class engines," Said Schag.
Performance Build Center Fast Facts
A $10 million, 100,000 sq. ft. facility in Wixom, Mich.
First product: Gen IV LS7 small-block V-8 for 2006 Chevrolet Corvette Z06
Specially trained technicians from UAW Local 653; each technician builds an engine from start to finish
Capacity: 15,000 engines annually; highly flexible "mix" can respond to quickly changing market conditions
Every engine to be hot-tested
SSR's Vortec 6000 6.0-liter ushers in fourth generation of small-block V-8
The new Gen IV Vortec 6000 6.0-liter V-8 (LS2) small block injects a new level of performance for the 2005 Chevrolet SSR.
Also new for 2005, the Gen IV Vortec 5300 5.3-liter small-block V-8 will feature GM Powertrain's Displacement on Demand cylinder deactivation to be rolled out in various 2005-model GM SUVs. In all applications, the Gen IV is revised in several key areas to enhance efficiency and durability, reduce friction and improve airflow.
For the 2005 SSR, the Vortec 6000 6.0-liter Gen IV small-block develops 390 hp at 5400 rpm and 405 lb.-ft. of torque at 4400 rpm. The SSR's Vortec 6000 6.0-liter LS2 is backed by a standard Hydra-Matic 4L65-E four-speed automatic transmission, or new for 2005, a Tremec M10 six-speed manual.
Numerous revisions, updates and improvements comprise the new Gen IV small-block V-8. "The new Gen IV engine is the best example yet of the continuous refinement in performance and efficiency that has been part of the small-block's legacy since day one," said Dan Nicholson, chief engineer of small-blocks.
A summary of new or changed components for the Gen IV architecture:
Larger 90-mm throttle body: The 6.0-liter displacement requires a higher volume of intake air; the Gen III throttle body is 75 mm. The new throttle body is mounted to a revised-design composite intake manifold with tuned runners to optimize airflow to individual cylinders.
New combustion-chamber design: Understanding of the flow characteristics in the highly tuned LS6 small-block were applied to the new Gen IV combustion chambers. The result is higher power output and increased volumetric efficiency.
Higher compression ratio: Hand-in-hand with Gen IV's new combustion chamber design is the ability to increase compression ratio to 10.9:1 compared to the 10:1 of the High-Output Vortec 6.0-liter Gen III V-8.
High-lift cam profile: Intake breathing is enhanced with a new, higher-lift camshaft. Also fitted are stronger valve springs to enable a higher peak-rpm range.
Flat-top pistons and stronger floating wrist pins: Floating piston wrist pins enhance durability, while engine testing and computer modeling demonstrated flat-top pistons generate the best power.
Compact, lighter water pump: All Gen IV V-8s are fitted with a more compact, more efficient water pump that reduces mass, conserves underhood space and reduces parasitic losses.
Deeper oil pan: The LS2 truck engine is designed with a deeper oil sump than the LS2 passenger-car engine. The new oil pan also incorporates a pass-through for a front driveshaft when used in four-wheel-drive applications.
Reduced-tension piston rings: Piston rings are a new, lower-tension design to reduce friction.
Redesigned crankcase vent: The crankcase vent is repositioned to the top of the block valley, where oil is less likely to enter during high engine speeds or high-g maneuvers.
New accessory-drive package: A new power steering pump and revised serpentine drive belt result in better space utilization.
Along with the increased power and torque when compared to the Gen III High Output Vortec 6.0-liter V-8, the new Gen IV Vortec 6000 6.0-liter continues GM Powertrain's ongoing commitment to reducing maintenance intervals and servicing costs.
Dexcool coolant and the platinum-tipped spark plugs have 100,000-mile change intervals. An Oil Life System function, built directly into the engine control module, calculates ideal oil-change intervals based on a variety of performance parameters.
Gen IV Vortec 6000 6.0-liter V-8 Fast Facts
First truck application: 2005 Chevrolet SSR
First small-block V-8 for truck applications to use aluminum cylinder block
390 hp (291 kW) at 5400 rpm
405 lb.-ft. (542 Nm) of torque at 4400 rpm
Numerous internal revisions enhance power as well as improve efficiency
GM Powertrain marks 50 years of small-block heritage
GM Powertrain is introducing its new Gen IV small-block V-8 architecture for several 2005 model GM vehicles exactly 50 years after the original small-block was launched for Chevrolet in 1955. One of any engine family's most important design elements - the distance between bore centers - remains the same 4.4 inches for today's new Gen IV as it was in Chevrolet Chief Engineer Ed Cole's seminal initial design.
Compact, powerful and packed with innovative technology: it's an accurate description of the new Gen IV V-8, and those same words were used to describe the original small-block in 1955.
In addition to its new, all-aluminum 6.0-liter variant for car and truck applications (LS2), the Gen IV architecture will be launched in V-8-equipped models of the 2005 Chevrolet TrailBlazer EXT, GMC Envoy XL and Envoy XUV, offering fuel-saving Displacement on Demand (DOD) technology.
"The small-block V-8 not only is a viable and relevant engine in today's market, but technology such as Displacement on Demand demonstrates its adaptability in the face of evolving marketplace expectations," said Dan Nicholson, chief engineer of small-blocks.
DOD has the capability to disable the combustion process of half the engine's cylinders in certain driving conditions, enabling fuel savings of up to 8 percent. The process is instantaneous and virtually imperceptible, and the engine delivers horsepower and torque bands comparable to previous non-DOD small-block engines.
The first passenger-car version of the Gen IV V-8 - without DOD - debuts in the 2005 Chevrolet Corvette.
GM Powertrain estimates that by the end of the 2005 model year, more than 90 million small-block-based engines will have been produced since the original engine's 1955 introduction.
Compact design the heart of small-block advantage
Contemporary demands for efficiency and performance refinements were the very demands that pushed the original small-block's development 50 years ago. It started in the early '50s with the planned replacement of Chevy's sturdy, but antiquated, straight-six engine - a large, heavy powerplant commonly called the Stovebolt Six.
Although a new V-8 was on the drawing table when Chief Engineer Ed Cole transferred from Cadillac to Chevrolet in 1952, he soon dismissed the original design and challenged his engineers to develop a more compact engine that would be easier to manufacture. The overhead valve design had been a staple of the Stovebolt engine and, to some at GM, one of the Chevrolet cars' selling points. Retaining that trait was agreeable with Cole, whose previous assignment was the design of Cadillac's OHV V-8.
When completed, the new V-8 engine had a minimalist design to take advantage of streamlined production techniques. Innovations like green-sand casting, which allowed the block to be cast upside down and dramatically reduce the number of cores, as well as lightweight stamped-steel rocker arms that allowed a much higher rpm range, were state-of-the-art.
The new small-block's cylinder heads were another important step forward. Their cross-flow port design and wedge-shape combustion chambers were very efficient and, when combined with the high rpm capability of the valvetrain, gave the new V-8 a broad performance band. Also, the engine's quintet of head bolts around each cylinder provided superior cylinder head location. Other innovations included:
Hollow pushrods to transfer lubricating oil to the cylinder heads
A single-piece intake manifold combined the water outlet, exhaust heat riser, distributor mounting and lifter valley cover in a single component
Internal lubrication eliminated the need for external oil lines, greatly reducing the chance for leaks
Compact size required less iron to produce the engine and less water to cool it during operation.
The internal oiling system was a breakthrough not found on many other automotive engines at the time, especially in Chevrolet's low-price field.
And though a seemingly inconsequential specification at the time, the new small-block engine also was designed with 4.4-inch bore centers - the distance from the center of one cylinder to the next. The design contributed to the engine's compact size, but the dimension has come to symbolize the balanced harmony of the small block. It was the dimension around which the all-new Gen III small block was designed in 1997.
"The long history of the small-block is one of the reasons the new generation of engines is so powerful and efficient," said Nicholson. "GM has almost 50 years of experience with its valve-in-head design, and that has provided immeasurable detail for keeping the small-block a viable, relevant engine for today and the future."
A legacy of power and adaptability
With 3.75-inch bores and a 3.00-inch stroke, the first small-block displaced just 265 cubic inches (4.35 liters). Drawing its breath through a two-barrel carburetor, the base version produced 162 horsepower (gross); with a four-barrel, the engine was rated at 195 (gross) in the Corvette. Better still, it weighed nearly 50 pounds less than the old Stovebolt Six.
From that auspicious beginning, the small-block was at the forefront of technology. A fuel-injected version of the engine was available from 1957 through the mid-‘60s, and as the horsepower wars of the late Sixties raged, the small-block proved to be powerful ammunition for Chevrolet.
The small-block would grow to a maximum of 400 cubic inches and, with the 2004 Corvette Z06's LS6 engine, produce 405 horsepower. In less glamorous, but perhaps more important roles, small-blocks reliably powered millions of family cars and work trucks.
When marketplace demands required more efficiency, the small-block was downsized to accommodate. But as engineers found new and better ways to extract power from the venerable engine, the small-block's displacement and power increased while meeting - or exceeding - federal requirements for fuel efficiency and lowered emissions.
In the early ‘90s, the Gen II small-block was introduced in high-performance cars including the Corvette and Pontiac Firebird Trans Am. Known as the LT1 and, later, the LT4, the Gen II featured new, low-friction internal components and reverse-flow cooling to enable the most powerful small-blocks since the heyday of the muscle car era. Some Gen II features, including the low-profile, high-flow, intake manifold previewed technology that would be incorporated into the all-new Gen III.
The Gen III was introduced as the LS1 5.7-liter engine in the 1997 Corvette, while Vortec versions of the Gen III for trucks were introduced in 1999, with displacements ranging from 4.8 liters to 6.0 liters. The Gen III engine benefited from new technology and production methods, but its design drew upon more than 40 years of research and continuous improvements from the Gen I and Gen II small-blocks.
Continual improvements also drove the development of new efficiencies and power increases in the Gen IV small-block.
Milestones
The legacy of the small-block has left an indelible mark on the global auto industry and American automotive culture. Some of its many noteworthy milestones include:
1955: Small-block V-8 introduced in 1955 Chevrolets.
1957: Larger bore increased displacement to 283 cubic inches (4.6 liters); Ramjet mechanical fuel injection was introduced, bringing horsepower to 283 - one horsepower for every cubic inch.
1962: Displacement increased to 327 cubic inches (5.4 liters), with Ramjet fuel injected version rated at 360 horsepower.
1964: Cylinder head improvements bump the 327's highest horsepower rating to 375 with fuel injection.
1967: Little-known option Z28 released for the Camaro, which includes a high-revving 302-cubic-inch (4.9-liter) small-block for competition in SCCA Trans Am road racing.
1968: A Camaro Z28 wins the Trans Am championship; a 350-cubic-inch (5.7 liters) version of the small-block debuts and would become the quintessential small-block variant.
1970: 350-cubic-inch LT1 debuts in Camaro and Corvette and is rated at 370 horsepower; 400-cubic-inch (6.6-liter) small-block is offered - the largest-displacement small-block built.
1975: With fuel economy prevalent in consumers' minds, a more efficient 262-cubic-inch (4.3-liter) small-block is introduced.
1978: V-6 engine based on small-block design introduced; it would become the Vortec V-6 truck engine more than a decade later.
1980: Last year for the 400 small block.
1982: Fuel injection reintroduced with the Cross-Fire injection system on Corvette and the redesigned Camaro Z28.
1985: Tuned port fuel injection replaces Cross-Fire Injection, ushering in the modern era of electronically controlled, port-injected engines.
1986: Aluminum cylinder heads debut as standard equipment on Corvette; block changed to accept new single-piece rear main seal.
1987: Hydraulic roller lifters introduced.
1989: The H.O. 350 "crate engine" is developed, offering a ready-built performance engine from the factory. It would change the way hot rodders approach engine building in the next decade.
1992: LT1 engine in the Corvette introduces Gen II small block design, which features reverse-flow cooling, revised cylinder head design, and crank-triggered optical distributor.
1996: Vortec V-8 engines introduced in trucks, featuring cylinder heads with swirl-inducing combustion chamber design to increase power and torque.
1997: Gen III 5.7-liter LS1 small-block introduced with all-new Corvette, featuring all-new deep-skirt block casting with six-bolt mains; redesigned cylinder heads with symmetrical ports and combustion chambers; and coil-near-plug ignition system.
1999: Gen III-based Vortec V-8 engines introduced in GM trucks; displacements include 4.8 liters, 5.3 liters and 6.0 liters.
2005: Gen IV small-block introduced 50 years after the original.
More than power or displacement, the significance of the small-block has been its adaptability as market demands and technology evolved during the past five decades. Engineers have met every challenge and kept the small-block on the leading edge of performance.
The introduction of the Gen IV engine signals the small-block's legacy will extend for decades to come.