LL8 Vega GT's Junkyard Dog

[grandam75]

Cool project and fun engine choice! I love straight 6 engines for the way they sound and how even and balaced they usually run. Actually did not know about this engine until I read this thread. Got me thinking of future projects..

[1100kaw]

Love the Engine combo. I'm hang n.
Darrell

[LL8 Vega GT]

Cool project and fun engine choice! I love straight 6 engines for the way they sound and how even and balaced they usually run. Actually did not know about this engine until I read this thread. Got me thinking of future projects..

I agree, and when I saw several of these engines modified running in the 7 second 1/4 mile range that was dang cool. there are also 2 different I5 versions of this engine that I considered messing with, they are in the small GM pickups (colorado etc)

here is some more info:
The LL8 (or Vortec 4200), is a straight-6 truck engine. It was the first Atlas engine, and was designed for GM's new SUV line. It displaces 4.2 L (4160 cc, 254 cu in), with a 93 mm (3.7 in) bore and 102 mm (4.0 in) stroke. When introduced, this engine's power was 270 hp (205 kW) at 6000 rpm and torque was 275 ft•lbf (373 N•m) at 3600 RPM. 2003 saw a slight bump in power to 275 hp (205 kW), while torque was unchanged. For 2006, power was increased to 291 hp at 6000 rpm and torque to 277 ft•lbf at 4800 rpm with the addition of a MAF and a complete internal redesign of the engine. The Atlas LL8 was on the Ward's 10 Best Engines list for 2002 through 2005. Engine redline is 6300 rpm.
LL8 Applications:
• 2002-2009 GMC Envoy, Envoy XL, and Envoy XUV
• 2002-2009 Chevrolet TrailBlazer and TrailBlazer EXT
• 2002-2004 Oldsmobile Bravada
• 2004-2007 Buick Rainier
• 2003-2008 Isuzu Ascender
• 2005-2009 Saab 9-7X
With the closing of the Moraine, OH plant and the termination of the GMT-360 platform (Chevrolet TrailBlazer, GMC Envoy, etc) the Atlas LL8 (Vortec 4200) has also been terminated. The smaller I4 and I5 variants are still produced.

[LL8 Vega GT]

A little more info:

VORTEC 4200 4.2L I-6 (LL8)
2006 model year summary

• Piston rod squirters
• Increased horsepower and torque outputs
• Higher 10.3:1 compression ratio
• Improved air flow
• Mass air flow sensor
• Improved A.I.R. system
• Improved ignition coils

Full descriptions of new or changed features

Piston rod oil squirters
The piston, inside the cylinder bore of the engine block, transfers energy through the connecting rod to the crankshaft. For improved durability and quietness the piston rod is now drilled with a tiny (less than 1/8th mm) hole, which allows oil to be sprayed on the cylinder wall, providing a cushioning layer on the sides of the piston which rides on the film of oil.The oil is originally pumped into the crankshaft, whose journals have cross-drilled holes. As the crankshaft rotates, pumping oil through the journals, the oil is fed from the journals through the piston rod bearing into the piston rod itself. Its open orifice then allows the oil to be sprayed into the cylinder wall.

Increased horsepower and torque
The Vortec 4200, already noted for providing peak power and torque emulating that of competitors’ larger-displacement V-8s, delivers 16 more horsepower for 2006. Its new rating is 291 hp and 277 lb.-ft. of torque. The power increase resulted from a higher compression ratio and improved engine breathing. GM Powertrain’s participation in the new SAE test certification procedure provides more accurate readings of in-vehicle performance by using more exact measures of exhaust backpressure and also accounting for loads put on the engine by the accessory drive.

Increased compression ratio
The Vortec 4200’s compression ratio increased to 10.3:1 as a result of changes to its piston profile, which lowered the volume in the combustion chamber. Even with its higher compression ratio, the engine continues to maximize fuel economy by allowing customers to use regular or unleaded fuel.

Improved air flow
Improved performance also results from increased airflow into and through the engine. A larger (38.7 mm) intake valve and larger (33.5 mm) exhaust valve allow more air to flow
through, and the camshaft also provides more lift to allow the valves to stay open longer.

Mass air flow sensor
A mass air flow system helps reduce emissions, allowing the Vortec 4200 to meet California LEV II emissions requirements while also improving its fuel economy.
The mass air flow (MAF) sensor (replacing a previous speed density fuel control system) more accurately measures air flow into the engine, eliminating variability in a number of conditions including changes in altitude and temperature, and allows more precise fuel and spark response.
The MAF is lightweight and has a modular design, using an integrated intake air temperature sensor. The electronics, located in the center of the sensor’s flow tube, are air cooled by the intake air. The output calibration is precisely programmed into the module.

A.I.R. system
The Air Injection Reaction (A.I.R) System, which pumps air into the port of each cylinder head, has also been upgraded to assist in reducing emissions. During the casting process, the A.I.R. port is now cast right into the cylinder head for improved air flow.

Ignition coils
The ignition system uses more compact coils, which also provide better reliability/ durability and make better use of its energy. Their more compact size saves an entire coil’s worth of weight. Enhanced durability has been proven from the coils’ use in other Gen III engines.

Overview
The award-winning Vortec 4200 4.2L I6 (LL8), which won rave reviews in virtually every automotive media outlet when introduced in 2002 and awards, including three consecutive appearances on Ward's Auto World's 10 Best Engines list, has continually been refined to optimize value and performance.
During the five years since the engine’s launch, virtually every system and technology, from emissions control to engine management to sealing, has been examined and refined. In 2003, the Vortec 4200 was fitted with polymer-coated pistons that reduce engine noise and enhance durability. The oil pump was refined to limit noise; and the cam-chain tensioner was improved for quieter operation. For model year 2004, the Vortec 4200 was introduced in the all-new Buick Rainier and Isuzu Ascender. In ’05 its variable valve timing, or cam phasing, system was equipped with a new state-of-the-art vane phaser. Along with previous GM midsize SUVs, ’05 also saw the Vortec 4200 introduced in the Saab’s first 9-7X SUV.
The Vortec 4200 originally debuted as the first inline six-cylinder engine in GM Powertrain’s lineup in nearly 20 years. While the industry largely had turned away from the inline six, GM recognized that, given careful design and development, the inherent advantages of inline six-cylinder architecture were perfect for the new millennium. With the technical sophistication of premium passenger car engines and the power of competitors’ V-8s, the Vortec 4200 is no ordinary inline six. Its flexible architecture provides the foundation for a range of inline engines, maximizing the return on corporate investment while exceeding customers’ performance expectations.
An exceptionally light, rigid engine block and cylinder head combination, cast with the GM's patented lost foam process, provide the foundation for the Vortec 4200’s success. All-aluminum construction means less weight than conventional cast-iron truck engines, and less weight means improved fuel economy. The bottom end of the engine derives
strength through many features, starting with a bearing beam, or ladder, that connects the seven main bearing caps to further stiffen the engine’s structure. The oil pan bolts to the transmission bell housing as well as the engine block, eliminating points of vibration and making the complete engine more like a single casting. The oil pan also gives “pan-axle” all-wheel drive capability to trucks equipped with the Vortec 4200. A passage cast through the width of the oil pan allows a drive axle to pass through it rather than under it, allowing the engine to be placed lower in the vehicle for a more compact package that improves the vehicle’s handling dynamics and gives designers greater styling flexibility.
The Vortec 4200's feature list reads like those for premium luxury/performance car engines: dual-overhead cam cylinder head, four valves per cylinder, roller-follower valve actuation and exhaust-cam phasing; a 10.3:1 compression ratio that delivers the seemingly incompatible benefits of high compression and regular-grade fuel; Electronic Throttle Control (ETC); and direct accessory mounting.
Vehicle platform teams recognize the Vortec 4200’s strengths, yet its design advantages and premium features mean little if the finished product doesn’t deliver what customers demand, like low maintenance. With Vortec 4200, oil changes are the only scheduled maintenance during the first 100,000 miles of operation, and even those are as stress-free as possible. GM’s Oil Life System (GMOLS) advises an oil change when it’s actually needed, based on real-world vehicle operation, rather than a predetermined mileage interval. The oil filter is easily accessible from underneath Vortec 4200-equipped vehicles and is mounted pointing straight down, reducing the potential for spilling oil during removal.
Most of all, customers demand performance and economy. Along with delivering even more peak horsepower and torque comparable to competitors’ larger-displacement V-8s, the Vortec 4200 also has higher EPA mileage ratings (based on published figures available in March 2005).
The Vortec 4200 is produced in Flint, Michigan.

[NixVegaGT]

Bitchin'. I totally love the idea. It will work well with the stock hood bulge I bet. Do you have any idea how much the engine weighs? Sorry I'm a bit obsessed with weight.

[LL8 Vega GT]

Bitchin'. I totally love the idea. It will work well with the stock hood bulge I bet. Do you have any idea how much the engine weighs? Sorry I'm a bit obsessed with weight.

I do not have an official weight, all I know is that when it is strapped to a pretty healthy skid ready to ship its about 450-475 lbs. according to the salvage yard. I would think that would be a little lighter than a iron SBC with with aluminum heads/intake? Anybody know what a ball park weight of an all aluminum small V8 of any make? this engine is all aluminum even cast aluminum pan that is very heavy because it is structural.

[77sjform]

I'm pretty sure a ls4 weighs around 470. Prob not remembering exactly, but thats close.

[rocketride]

I'm pretty sure a ls4 weighs around 470. Prob not remembering exactly, but thats close.

DING DING DING. We have a winner. Scroll all the way to the bottom.
http://vortec4200.com/tech.htm

Pretty good power for a small engine.
http://www.youtube.com/watch?v=rjvW8Iim ... re=related

And they sound mean. Not the best video quality.
http://www.youtube.com/watch?v=PUESVD-P ... re=related

Good luck with the build.

Jon

[LL8 Vega GT]

That video of the nova is my favorite, I believe that engine was built by kevin self and was on the dyno at around 1400HP

There are more videos of the engine on the dyno, it is in a truck that belongs to Marc in canada, he has done a great deal of work with these engines, i bought his EDIS setup for my engine that came off one of his. It has a turbo on it now and the chassis dyno video is pretty killer. Its a pretty small group of people messing with these engines.

[NixVegaGT]

Hot motorhead porn of that Nova. Pretty awesome. 4" stroke. WOW.

[LL8 Vega GT]

4" stroke. WOW.

I always thought the 4" stroke was awesome, i think for a stock engine the 291HP and 277ftlbs of torque were pretty good #'s
Hard to buy that much motor for $1200 in brand new condition anywere

[LL8 Vega GT]

A simple 3x2 square tube frame, started with the frame rails. Used a fixture plate to get them flat and square. Used the first rail as a template for the second rail.

[LL8 Vega GT]

Here are some more front clip construction pics.

[grandam75]

A simple 3x2 square tube frame, started with the frame rails. Used a fixture plate to get them flat and square. Used the first rail as a template for the second rail.

Impressive fabrication! What kind of table is that?

[Wizeguyrc]

Very nice.

Tracy