The Forgotten Inline Engine: GM’s 4.2-liter Atlas I-6
General Motors has a long history with making innovative strides in engine development. The Chevrolet small-block V-8, for example, began life in the 1950s and soon became the standard for high horsepower in a small package – a legacy that continues into today’s fifth-generation GM V-8s. Even GM’s lineup of V-6 engines is impressive, ranging from the 60-degree V-6 that powered nearly every GM car from 1980 through 2010, up to the twin-turbocharged V-6 powering the Cadillac ATS-V. However, GM has a lesser-known engine family that deserves admiration for its outside-the-box thinking and outstanding technological advancements: the Atlas inline family.
That Atlas family had three main members, the front-running 4.2-liter inline-six, the 3.5-liter five-cylinder, and the 2.8-liter four-cylinder. All three shared the same basic architecture and a wide range of parts, though it was the 4.2-liter that led the Atlas program.
The 4.2-liter called the GMT360 platform home. This included the Chevrolet Trailblazer, GMC Envoy, Buick Rainier, Oldsmobile Bravada, Isuzu Ascender, and Saab 9-7X. Each of these mid-sized SUVs shared the same architecture, including the industry’s first fully hydroformed frame in a mid-size SUV. Introduced for the 2002 model year, the GMT360 platform sold a couple million examples worldwide before ending production after 2009.
The 4.2-liter Atlas LL8, otherwise called the Vortec 4200, was a groundbreaking engine for GM. It featured an all-aluminum construction, dual overhead cams with variable valve timing on the exhaust side, four valves per cylinder, a coil-on-plug ignition system, a high compression ratio of 10:1, and its cylinder heads featured GM’s then-prevalent “Vortec” engineering designed to maximize airflow.
This combination allowed for the production of 1.06 horsepower per cubic inch – a total of 270 horsepower at 6,000 rpm. Torque was rated at 275 pound-feet at 3,600 rpm, but 90 percent of peak torque was available between 1,600 and 5,600 rpm. These stats far exceeded every comparable V-6 on the market at the time, including GM’s own 4.3-liter Vortec V-6.
We decided to take a closer look at the Vortec 4200 and its forward-thinking design. We reached out to GM and found Tom Sutter, the Assistant Chief Engineer for the Atlas. Sutter has been involved with engine programs for the last 30 years, ranging from Oldsmobile’s Quad Four to Cadillac’s current V-Series mills. Sutter was able to give us a deeper insight into the Atlas program, so keep reading for more.
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Speedriven has been building some of the highest performing engines on the market for some time no and has released details on their newest project. Starting with a base CL600, this tuning team takes it from a tame luxury coupe and changes it into the most powerful CL on the market.
This firm is not about making your Mercedes the most ridiculous or unique looking car on the road, but rather focuses their attention exclusively under the hood. These are already some of the best looking luxury coupes on the market and there is no need for oversized chrome rims or carbon fiber aero-pieces to make it look fast – Speedriven would much rather make it perform to its highest potential.
The package is available for all models 2003+ that feature the Mercedes V12. This includes the ultra-exclusiveMaybach models. If you want Speedriven to turn your car into the ultimate Mercedes without adding the usual array of aftermarket exterior pieces then it’s going to cost $16,250. This price is not actually that ridiculous considering that companies like Brabus and Renntech charge much higher rates and don’t usually equal the same performance figures.
More details on the Mercedes CL600 by Speedriven after the jump.
Bertone and BMW have been working together since 1960 when the car-maker from Munich commissioned the Turin designer to revamp the styling of the V-8 engined 502 saloon (in production since 1957), modifying the front, the wings and the rear end. In 1961, BMW commissioned Bertone to produce the 3200 CS, a top performance 4-seater coupé with a 3.2 litre V8 engine. In design terms, the car had a classic, smooth line and generous glazing. The 3200 CS debuted at the 1961 Frankfurt Motor Show, and remained in production until 1965 (597 were built). In 1966, Nuccio Bertone designed the E3, a styling study for a top of the market saloon.
In autumn 2003, Ford presented to the world its newest concept at car at that moment – The Visos. Many said that this is an attempt to resurrect one of Fords oldest legends, The Capri. The resemblance between the two is on individual character level, yet some visual ones as well. Officials never said anything about this, but it is clear that they are trying to send a message to automobile fans: that this is the design direction Ford wishes to go.
The Moray project, which will be presented for the first time at the Geneva Motor Show on March 4, 2003, embodies the homage that Giorgetto and Fabrizio Giugiaro wish to pay to the fifty-year era of the Chevrolet Corvette, the supreme symbol of the American sports car.
Produced from 2001 to 2006 model years, the original Acura broke new ground in the emerging luxury SUV segment. Taking its predecessor’s best qualities and radically expanding them, the all-new 2007 MDX pushes performance and sophistication in the luxury SUV segment to new levels. Benchmarked against some of the best performance SUVs in the world and tuned on the Nurburgring racetrack in Germany, the new MDX clearly establishes itself as a driver’s SUV. Outfitted with Acura’s tenacious Super-Handling All-wheel Drive system and an available sport package with Active Damper System, the MDX yields a combination of handling and comfort that is truly on the cutting edge.
The Acura RSX debuted in 2001 as a replacement for the Acura Integra. From 2001 to 2004 it was offered in standard or Type S form. The standard RSX used the K20A3 four-cylinder engine that delivered 160 horsepower, while the Type S had the 200 horsepower K20A2. Both versions carried over unchanged until 2005. In 2005, the RSX went through a refresh that gave it new headlights and taillights, and an updated rear spoiler. The Type-S now came with 17-inch wheels as standard equipment, but the real change came under the hood. The standard RSX remained the same, but the Type-S got a K20Z1 powertrain that utilized the camshafts from the Japanese DC5 Type R, as well as the b-pipe, muffler and 4.77:1 final drive ratio. The standard RSX was offered with a five-speed manual or five-speed auto with sequential SportShift technology. The RSX Type-S was only available with a close ratio six-speed manual transmission.
The RSX had a short lifespan and was only produced from 2001 to 2006. Because of its similarity to the seventh-gen Civic, it became common to swap the Type-S’ K20Z1 engine and transmission into the seventh-gen Civic. Oddly, from 2001 to 2005, the RSX was offered with a number of exterior colors, but consumers were limited to either black or beige interior, normally dictated by the exterior color. The RSX wasn’t a bad car, and it was a suitable replacement for the Integra, but the seventh-gen civic was a bit of a flop, so it’s no surprise that the RSX didn’t last past 2006. With that said, let’s take a look back at the 2001 to 2005 Acura RSX and talk a little more about it.
The Pagani Zonda made its official debut in 1999 and was in production until 2011. In those 12 years, the Zonda was offered in a number of different variants, with three different Mercedes-AMG sourced engines. The first model was dubbed the Zonda C12, and it debuted at the 1999 Geneva Auto Show. It was offered with a 6.0-liter AMG engine, but that wasn’t good enough, and three years later, Pagani released the Zonda S 7.3 – a better interpretation of the Zonda C12 with an AMG 7.3-liter engine. Just one year later, Pagani released the 2003 Zonda Roadster.
The Zonda Roadster shared most of its components with the Zonda S 7.3 that came before it, but it had the ability to go topless should its owner want to feel the breeze. The car was made possible thanks to a new central monocoque structure that was made entirely of carbon. Thanks to this monocoque, the car had optimal structural rigidity, even with the top removed. The overall design allowed for a dry weight of just 2,821 pounds, which wasn’t bad at the time. To give you an idea of the significance of that weight, the 2007 Lamborghini Gallardo Spyder tipped the scales at 3,351 pounds.
There was a total of 40 examples of the Pagani Roadster built. Each model was also different, as customers were allowed to specify things like materials and finishes according to their individual tastes. So, with that said, let’s take a look at a little piece of Pagani history.
Keep reading to learn more about the Pagani Zonda Roadster.
The Concept TL is true to Acuras design lineage. No surprises here, just a new adaptation of the crisp, clean lines that have made the current midsize Acura sedan such a popular seller in the first place.
"Every aspect of this concepts design, from the aggressive front end to the short rear overhang, contributes to an aggressive, muscular style that conveys the TLs high-performance nature," added Elliott.
Most of what makes up the CL are components straight from the Acura/Honda parts bin. The unibody chassis is derived from the Accord’s and features unequal length A-arms in front and a five-link system in the rear for suspension. The engine is a 3.2-liter version of the SOHC 24-valve V-6 that’s used as a 3.0-liter in the Accord and as a 3.5-liter in the Honda Odyssey minivan and Honda Pilot and Acura MDX SUVs. Mechanically (at least up until now) anything that distinguished the CL from other Hondas and Acuras it shared with the TL sedan.
Sport coupes often demand the driver sacrifice comfort and convenience for sport. The Acura CL minimizes this. It’s an easy car to live with. The CL is designed for drivers who want the comfort and quality of a luxury car but the handling, power, and sporty image of a coupe. The CL achieves all of this with a cabin that’s comfortable, convenient and luxurious, a smooth, quiet ride, agile handling, and plenty of power. Though it won’t draw stares from kids on skateboards, it is attractive and sporty.