Curtis A. Franz

The Gen IV small-block V-8, with higher performance and an array of technical advancements. The Vortec 5300 small-block with DOD debuts on V-8-equipped versions of the 2005 Chevrolet TrailBlazer EXT, GMC Envoy XUV and Buick Rainier. An automotive application of the Gen IV small-block without DOD debuts later in the 2005 Corvette.

Boy I sure don't like that last sentence. The Vette version of the Gen IV will debut later than 2005 5300 truck's version!. They have also announced an SS version of the Trailblazer will be built for the 2006 model year. All this at the SEMA show.

:chevy

GDP

I think that they mean that it won't be debuted until later on, not later on in the Corvette production.

Hernan

Wow, you can see the future, can you tell me who is gonna win the Superbowl :smash: (Nov 28) :lol:

:jester JK, thanks for the info :thumbs:

Curtis A. Franz

Okay time for some more pressure. There are two names at the bottom of this press release with email addresses. I emailed the latter asking if, indeed, the Corvette was coming out after the trucks. More email with different questions might help clarify this potential mess.
http://media.gm.com/events/sema/sema03gm/

:chevy

Runge_Kutta

For Release: Oct. 28, 2003, 8 a.m. ET

GM INTRODUCES GEN IV SMALL-BLOCK V-8 FOR TRUCKS
NEW VORTEC 5300 FEATURES FUEL-SAVING DISPLACEMENT ON DEMAND TECHNOLOGY FOR ’05 TRAILBLAZER EXT, ENVOY XL AND ENVOY XUV

PONTIAC, Mich. – GM is writing a new chapter in the history of the small-block V-8 with the Gen IV engine, which, when equipped with its innovative Displacement on Demand (DOD) technology in trucks, has the capability to operate more efficiently on fewer cylinders.

DOD technology enables fuel economy gains of 6 percent to 8 percent in certain light-load driving conditions by reducing the number of cylinders engaged in the combustion process. The Vortec 5300 small-block with DOD debuts on V-8-equipped versions of the 2005 Chevrolet TrailBlazer EXT, GMC Envoy XL and Envoy XUV. A version of the Vortec 5300 V-8 without DOD is available in the 2005 Buick Rainier.

An automotive application of the Gen IV small-block without DOD also debuts later in the 2005 Corvette.

“The versatility, strength and performance of the legendary small-block V-8 continue to grow,” said Sam Winegarden, chief engineer of small-block engines. “In trucks we’ve maintained the broad, usable torque customers depend on for countless tasks, while in the Corvette, we’ve upped the ante with the largest, most powerful small-block ever offered as standard equipment. You’ll have to wait until the 2004 North American International Auto Show to get the details, but believe me, it’s worth the wait.”

Virtually imperceptible
The Vortec 5300 all-aluminum truck engine with DOD is rated at an estimated 290 horsepower and 325 lb.-ft. of torque in V-8 mode, and supports tow capacities comparable to the previous 5.3-liter small-block. A sophisticated, next-generation engine controller determines when to deactivate cylinders, allowing the engine to maintain vehicle speed in lighter-load conditions such as highway cruising. The process is seamless and virtually imperceptible.

When the cylinders are deactivated the engine effectively operates as a V-4, with alternate cylinders on each cylinder bank disabled. The engine returns to V-8 mode the instant the controller determines the vehicle speed or load requires additional power.

“Displacement on Demand is a win-win for drivers who rely on the power of the small-block V-8 and are conscious about fuel economy,” said Chris Meagher, assistant chief engineer of small-blocks for trucks. “The implications of this technology are tremendous.”

Factors including oil temperature, rpm, coolant temperature and throttle position help determine the operating mode of the engine. The engine controller automatically shifts between operating modes as these factors and driving conditions dictate.

“From behind the wheel, there’s no indication or sensation that the operating mode of the engine has changed,” said Meagher. “DOD operates only in conditions when the load on the engine doesn’t require all eight cylinders – the torque to climb a hill, to pass or tow is never compromised.”

Two-stage lifters
The key to DOD’s efficiency and virtually imperceptible operation is a set of special two-stage hydraulic valve lifters, which allows the lifters of deactivated cylinders to operate without actuating the valves.

The lifters have inner and outer bodies, which normally operate as a single unit. When the engine controller determines cylinder deactivation conditions are optimal, the outer body moves independently of the inner body on the disabled cylinders’ lifters. The outer body moves in conjunction with camshaft actuation, but the inner body does not move, holding the pushrod in place. This prevents the pushrod from actuating the valve, thereby halting the combustion process.

Solenoids in the engine lifter valley operate to deliver high-pressure oil to the switching lifters, activating a release pin to separate the inner and outer bodies. Oil circulation and pressure do not vary regardless of the engine’s operational mode. Lifter design and pushrod length are the same for every cylinder, but camshaft lobe profiles differ for cylinders designated to be deactivated.

Because the vibration and acoustic dynamics of the V-8 and V-4 modes are different, engineers tuned the exhaust system of DOD-equipped vehicles to compensate for the changes. A pressure-activated valve in the muffler automatically switches when the engine mode changes, adjusting the exhaust path to deliver the appropriate noise reduction. Additionally, tuned exhaust and engine mounts were designed for the multiphase engine operation.

The engine’s electronic throttle control (ETC) also is used to increase manifold pressure in V-4 mode so that the engine can maintain a V-8 torque load.

Gen IV features
Based on the architecture of the Gen III small-block introduced in GM trucks in 1999, the Gen IV engine incorporates several significant design changes:

* New casting for iron and aluminum blocks with redesigned oil galleries to support DOD oiling requirements
* Knock sensor locations moved out of lifter valley to provide room for DOD lifter oiling solenoids
* Camshaft sensor relocated from the rear of the block to the front of the block provides room for new oil galleries
* Higher capacity oil pump accommodates increased oil circulation requirements of DOD
* Coil-near-plug ignition has larger, more efficient coils that require less energy to produce a comparable spark
* Returnless fuel system for improved evaporative emissions
* Larger throttle body angled upward for improved water drainage
* Electronic throttle control (ETC) on all models for improved throttle response and DOD signaling
* Next-generation engine controller operates DOD, ETC and other engine functions
* Separate controller for transmission

Additionally, the Vortec 5300 benefits from continual improvements incorporated into later versions of the Gen III engine, including iridium-tip long-life spark plugs; pistons with floating wrist pins; a redesigned water pump that significantly reduces the probability of a leak; and a stronger, long-life timing chain. It also is compatible with E-85 fuel.

Gen IV engines share the deep skirt engine block design of previous GM truck engines. Extending below the crankshaft centerline, the rigid block contributes to world-class smoothness and strength. It also allows cross-bolted main bearing caps for additional strength and dimensional accuracy.

The engines’ similarities also include the balanced cylinder head design, which promotes optimal performance and efficiency with identical airflow and energy direction to each cylinder. A tall intake manifold plenum helps draw a longer, tuned path for incoming air to build low-rpm torque, allowing the engine to make torque at low rpm and sustain it over a broad rpm band.

“The Gen IV’s new features and proven architecture ensure the vitality of the small-block V-8 into the foreseeable future,” said Meagher.

More than 2 million DOD-equipped vehicles will be on the road by 2008.

GM Powertrain is a global producer of engines, transmissions, castings and components for GM vehicles and other automotive, marine, and industrial OEMs. Headquartered in Pontiac, GM Powertrain has operating and coordinating responsibility for General Motors powertrain manufacturing plants and engineering centers in North America, South America, Europe, and the Asia-Pacific region.

General Motors Corp. (NYSE: GM), the world's largest vehicle manufacturer, employs 342,000 people globally in its core automotive business and subsidiaries. Founded in 1908, GM has been the global automotive sales leader since 1931. GM today has manufacturing operations in 32 countries and its vehicles are sold in more than 190 countries. In 2002, GM sold more than 8.6 million cars and trucks, nearly 15 percent of the global vehicle market. GM's global headquarters is at the GM Renaissance Center in Detroit. More information on GM and its products can be found on the company's consumer web site at http://www.gm.com.


Contact:
Randal Fox
GM Powertrain Communications
Phone: (248) 857-0323
E-mail: randal.l.fox@gm.com

Runge_Kutta

For Release: Oct. 28, 2003, 8 a.m. ET

GEN IV V-8 MARKS 50 YEARS OF SMALL-BLOCK PERFORMANCE

PONTIAC, Mich. – Compact, powerful and packed with innovative technology – it’s an accurate description of the modern GM small-block V-8. Those words also were used to describe the original small-block when it debuted in 1955.

GM will introduce the Gen IV small-block V-8 50 years after the first small-block. It will be available 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 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 Sam Winegarden, chief engineer of small-blocks. “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.”

DOD has the capability of disabling the combustion process of half the engine’s cylinders in certain driving conditions, enabling fuel savings of 6 percent 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.

A car version of the Gen IV engine without DOD will debut 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
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 carried 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 Winegarden. “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 ’60s 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 served as quiet servants in untold millions of family cars and work trucks.

The small-block’s versatility also found a place in countless vehicles probably never considered by its designers. Everything from industrial equipment to marine applications of all sizes has used the GM small-block as standard equipment. It has become a staple of auto racing circuits of all types, too, and some industrious builders even have squeezed the engine into custom motorcycles.

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 1978 engineers developed a V-6 engine from the original small-block’s architecture. Called the “three-quarters small-block” at the time, the engine lives on today in many GM trucks as the Vortec 4300 V-6.

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
That 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; Ramjet mechanical fuel injection was introduced, bringing horsepower to 283 – one horsepower for every cubic inch.
1962: Displacement increased to 327 cubic inches, 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 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 small-block is offered – the largest-displacement small-block built.
1975: With fuel economy prevalent in consumers’ minds, a more efficient 262-cubic-inch 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.

GM Powertrain is a global producer of engines, transmissions, castings and components for GM vehicles and other automotive, marine, and industrial OEMs. Headquartered in Pontiac, GM Powertrain has operating and coordinating responsibility for General Motors powertrain manufacturing plants and engineering centers in North America, South America, Europe, and the Asia-Pacific region.

General Motors Corp. (NYSE: GM), the world's largest vehicle manufacturer, employs 342,000 people globally in its core automotive business and subsidiaries. Founded in 1908, GM has been the global automotive sales leader since 1931. GM today has manufacturing operations in 32 countries and its vehicles are sold in more than 190 countries. In 2002, GM sold more than 8.6 million cars and trucks, nearly 15 percent of the global vehicle market. GM's global headquarters is at the GM Renaissance Center in Detroit. More information on GM and its products can be found on the company's consumer website at http://www.gm.com.


Contact:
Randal Fox
GM Powertrain Communications
Phone: (248) 857-0323
E-mail: randal.l.fox@gm.com

yellow01

I love that last sentence... no DOD on the corvette!

Curtis A. Franz

I love that last sentence... no DOD on the corvette!



that has been a known from a previous Dave Hill announcement.

:chevy

Scissors

Likely done because the added bits for exhaust tuning would add weight.

Kevin93

Did anyone else catch the key words "biggest" and "most powerful???" :cheers: I guess that puts to bed the question of power relative to today's ZO6! Anyone know if GM has ever made a small block bigger than 350ci??

:party:

johnnyvettes

yes they have i have to say in the late 70s they built a 400 cubic inch small block :yesnod: :yesnod:

ModRed405

"most powerfull" standard engine ever offered.


[Modified by Christian, 9:09 PM 10/28/2003]


[Modified by Christian, 9:09 PM 10/28/2003]

bigblockbob

the 6.0 is one of the bigest.... :thumbs:

FAST LS1

Does this 5.3L 290hp 325ft trq engine have the 3V heads, or is this still a 2 valve engine?
If it's only a 2 valve that's pretty unbelievable, and would mean a 3V version of the 5.3L would have about 330-340hp.

I'd assume it's a 2V and they improved the heads that much.
500hp seems almost definate with the 3V heads and 6.4L :cheers:

HellBent

[QUOTE]Did anyone else catch the key words "biggest" and "most powerful???" :cheers: I guess that puts to bed the question of power relative to today's ZO6!:party:

"most powerfull" standard engine ever offered.

Hmmmm... don't know if this means much. If they are counting the base coupe engine as standard. Then anyting larger than 5.7L and 355HP is the largest most powerful standard engine ever offered. Hopefully we will see the magic 400 HP and then some.

yellow01

Whoops! Haven't been able to keep up with eveyrthing! Thanks :cheers:

Jinx

LS6 is standard on the Corvette Z06, which is its own model. So it could be taken either way.

.Jinx

Daryl

IMO The new non-Z06 engine will in fact be the most powerful small block corvette engine ever. I also believe that this engine will have a horsepower rating in excess of the current Z06. Which means that the actual availibility of the C6 would have to be somewhat late in the model year (August/September). GM needs the time to sell the remaining Z06's.

WhiteDiamond

If I remember another release that was posted not too long ago, C6 Vette availability is not supposed to be until 4th quater 2004. That gives GM plenty of time to move the C5 off the showroom.

Todd

scorp508

Yup, and I've been saying it for well over a year now. :)