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From:http://www.saturnfans.com/Cars/Future/2.4lecotecfuture.shtml

2.4L Ecotec Slated for 2005-06 Saturns
SaturnFans.com · November 10, 2003
GM Powertrain's new Ecotec 2.4-liter four-cylinder engine, slightly modifies that well-used adage, "There’s no substitute for cubic inches." In the case of this slightly larger version of the original Ecotec 2.2-liter, one of GM's highest-volume engine families, there are a few more cubic inches found in the new 2.4-liter variant. But along with the larger displacement, which has become vital in the increasingly competitive compact-car segment, the 2.4-liter for the first time brings variable valve timing to the Ecotec modular engine family.

"We have added technology to improve low-end torque and continue to reduce emissions," said Jay Subhedar, Ecotec global four-cylinder engine assistant chief engineer. "For the new Ecotec, variable valve timing helps deliver 90 percent of the torque peak at as low as 2400 rpm. That sort of responsiveness enormously enhances engine response."

The combination of slightly more displacement and variable valve timing enables the Ecotec 2.4-liter to achieve one of the highest torque ratings – an estimated 170 lb.-ft. – for a 2.4-liter normally aspirated four-cylinder in the United States And the Ecotec 2.4-liter's 170 horsepower at 6000 rpm also is one of the highest specific-power outputs for any non-boosted four-cylinder of any size sold in the U.S., according to Ward's 2003 market data.

The new Ecotec 2.4-liter engine's torque-rich power delivery and its designed-in refinement deliver a driving experience that will please both performance-oriented buyers and those simply seeking a more sophisticated feel from a compact-car powertrain.

Intelligent Technology as Important as Cubic Inches

Increasing displacement is perhaps the most-proven technique to improve horsepower and torque, and that’s where GM Powertrain engineers started when developing the Ecotec 2.4-liter. For the new 2.4-liter variant, both cylinder bore and stroke are increased in relation to the original Ecotec 2.2-liter engine. The new engine's bore is 88 mm and stroke is 98 mm, versus the 2.2-liter's 86-mm bore and 94.6-mm stroke. These increases, multiplied by each of the Ecotec 2.4-liter’s four cylinders, yield a total displacement of 2,384 cubic centimeters versus the original 2.2-liter's 2,189 cubic centimeters.

But equally important to delivering class-leading torque is the Ecotec 2.4-liter’s new variable valve timing system, developed to enhance the low- and midrange torque output of the new engine.

The new variable valve timing system uses electronically controlled hydraulic camshaft phasers to alter the relationship of the intake and exhaust camshafts as much as 50 degrees relative to the crankshaft. Yet the system adds little weight or assembly complexity to the basic Ecotec DOHC architecture because the Ecotec family was designed from the beginning to easily accept technology advances such as variable camshaft phasing.

But the new Ecotec 2.4-liter's technology story hardly stops there. The new Ecotec enjoys a host of new technical enhancements:


Electronic throttle control. The ETC system eliminates the physical connection between the accelerator pedal and the engine throttle. This well-proven "drive-by-wire" control allows for remarkably precise engine control and response, while simultaneously enhancing the engine’s interface with other vehicle systems.
An all-new, engine control module (E67). The Ecotec 2.4-liter is one of the first GM engines to employ this sophisticated new controller that leverages 32-bit processing power. It incorporates 32 megabytes of burst flash memory and 32 kilobytes of external RAM and 36 kilobytes of internal RAM, as well as a high-speed CAN bus to deliver optimal networking capability.
All engine-related sensors for the Ecotec 2.4-liter are digital rather than analog. “Digital sensors are more accurate and provide improved reliability,” said Subhedar of this emerging trend in engine-monitoring technology. The digital sensors improve information processing and reliability, which in turn means more-efficient engine performance.
Individual coil-on-plug ignition modules improve upon the two-coil "cassette" of the original Ecotec design. The individual ignition modules for each spark plug enhance combustion and engine energy efficiency.
Twin counter-rotating balance shafts, inherent in the Ecotec engine architecture, spin at twice the speed of the engine crankshaft to cancel the second-order vertical shaking forces experienced by inline four-cylinder engines. The balance shafts are driven by the quiet and efficient, zero-maintenance chain-drive system that operates the engine's camshafts and water pump
Ecotec's Robust Design, Structure Enhanced for New 2.4-Liter Variant

Along with significant new technology additions, the new Ecotec 2.4-liter enjoys numerous upgrades to the robust basic Ecotec engine architecture. The Ecotec design, already noted for impressively low levels of noise and vibration, includes features like a structural oil pan; full-circle transmission mounting flange; a highly rigid lower crankcase with four-bolts at each bulkhead; long cylinder-head bolts to assure robust clamping of the cylinder head to the engine block; and direct-mounted accessories to eliminate these traditionally large contributors to engine noise, vibration and harshness.

The Ecotec 2.4-liter's basic structure has been enhanced in several significant ways to ensure the engine's increased displacement and power do not compromise the Ecotec's high levels of inherent refinement. "In the global engine family, we look at various engine components to evaluate which are the right 'fit' for any given engine application," said Subhedar. "Commonality is a vital part of the Ecotec program – it's like an interlocking puzzle. We try to choose the best combination of components from the myriad of available technologies.”

Thus the Ecotec 2.4-liter leverages several heavy-duty components and systems borrowed from the high-performance Ecotec supercharged 2.0-liter engine program, plus many that are unique to the new 2.4-liter variant:


An auxiliary oil cooler that is approximately 30 percent smaller than similar-capacity oil coolers used on other engines.
Piston-cooling oil jets spray the underside of each piston with a continuous bath of engine oil, increasing longevity by reducing engine operating temperatures.
Redesigned cylinder head with structural improvements and new multi-layer steel gasket.
New camshafts with optimized lobe profiles.
Enhanced lubrication system to provide for the extra requirements of the camshaft phasers and piston-cooling jets, along with a deeper oil sump to handle the higher potential cornering forces.
The Ecotec 2.4-liter will be built at GM Powertrain's Spring Hill, Tennessee, assembly facility. The 2.4L Ecotec will be launched in the all-new 2005 Chevrolet Cobalt, and is reportedly slated for use in 2005 or 2006 model year Saturns.

Source: General Motors
 

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From:http://www.ai-online.com/issues/article_detail.asp?id=352

2.4L Ecotec


The 2.4L Ecotec four-cylinder powerplant will be a performance option on the 2005 Chevrolet Cobalt, the Cavlier replacement.


GM will also introduce variable valve timing to the Ecotec four-cylinder engine family. A 2.4L Ecotec will be an optional powerplant in the 2005 Chevrolet Cobalt.

Starting with the 2.2L variation, GM engineers increased both cylinder bore and stroke by 88mm and 98mm respectively. The engine is expected to deliver 170 hp at 6000 rpm and 170 lb.-ft. of torque over a 2400 to 5600 rpm range thanks to VVT.

The VVT system uses the same hydraulic cam phasers found on the V-6 but can alter the relationship of the intake and exhaust camshafts by as much as 50 degrees relative to the crankshaft.

The new four-banger is also equipped with electronic throttle control and shares the V-6’s E67 engine control module.

All analog engine sensors have been replaced with more accurate digital sensors and individual coil-on-plug ignition modules improve upon the two-coil “cassette” found on the original Ecotec. Twin counter-rotating balance shafts are driven by a zero-maintenance chain that also drives the camshafts and water pump.

Leveraging the experience from its NHRA front-drive drag racing programs, GM has fitted the 2.4L Ecotec with several heavy-duty components and systems.

A redesigned cylinder head is improved structurally and has a multi-layer steel gasket. There’s also a smaller, more efficient external oil cooler, new camshafts, piston-cooling oil jets that spray a continuous bath of oil on the underside of the piston reducing engine operation temperatures and an enhanced lubrication system that provides for the extra requirements of the VVT and piston-cooling jets, plus a deeper oil sump to handle the potential higher cornering forces.

The Ecotec 2.4L will be built at GM’s Spring Hill, Tenn., assembly facility.
 

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Sounds great, but with all the computer chips, micro processors and "Drive by Wire", we all better be triple A members. There won't be anymore get out, get under the hood with the tool kit, and get back on the road. Maybe someone will come up with a digital emergency repair tool kit for the cars of the future. Needing a tow truck sucks.
 

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sounds to me that all this is going to make throwing a turbo on there all the more difficult, but i like the piston cooling oil jets they'll be using, sounds like it will make this engine more reliable, but then again, im no expert
 

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"The engine is expected to deliver 170 hp at 6000 rpm and 170 lb.-ft. of torque over a 2400 to 5600 rpm range thanks to VVT."

They aren't teaching basic math anymore ? (170 lb-ft at 5600 rpm = 181 hp). 4600 maybe. 6000 rpm is quite high for a long stroke (nearly 4 inches) engine, suspect the peak is lower and that is the redline.

I don't get under the hood first anymore, I just connect my scan tool and see what is happening :jester
 

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padgett said:
"The engine is expected to deliver 170 hp at 6000 rpm and 170 lb.-ft. of torque over a 2400 to 5600 rpm range thanks to VVT."

They aren't teaching basic math anymore ? (170 lb-ft at 5600 rpm = 181 hp). 4600 maybe. 6000 rpm is quite high for a long stroke (nearly 4 inches) engine, suspect the peak is lower and that is the redline.

I don't get under the hood first anymore, I just connect my scan tool and see what is happening :jester
what kind of scan tool do you have? it might not work with the CAN bus.
 

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I have several scan tools. For ease of use there are a couple of OTC 2000s. For serious work I have both DiaCom and Craig Moates PC connections. Right now my "new" car is a '92 so just need 8192 baud P4 connectivity. Am sure that there are similar pieces for OBD II.

For troubleshooting oddball problems, the PC based tools are best as you can capture a stream of frames and mark where the problem occurs - was able to find an intermittant TPS problem in the Fiero that way.

Best GM car for troubleshooting is the 88-89 Buick Reatta. Hit WARM and OFF at the same time and the 5" touchscreen in the dash becomes a scan tool with capture. You can also toggle most of the discretes from the touchscreen and clear fault history which most aftermarket tools cannot.

If none are available when the Solstice comes out, I'll just program one.

Sure beats rolling a Brush chart down a long hallway and looking for anomalies in a F-16 flight control computer :patriot
 

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padgett said:
I have several scan tools. For ease of use there are a couple of OTC 2000s. For serious work I have both DiaCom and Craig Moates PC connections. Right now my "new" car is a '92 so just need 8192 baud P4 connectivity. Am sure that there are similar pieces for OBD II.

For troubleshooting oddball problems, the PC based tools are best as you can capture a stream of frames and mark where the problem occurs - was able to find an intermittant TPS problem in the Fiero that way.

Best GM car for troubleshooting is the 88-89 Buick Reatta. Hit WARM and OFF at the same time and the 5" touchscreen in the dash becomes a scan tool with capture. You can also toggle most of the discretes from the touchscreen and clear fault history which most aftermarket tools cannot.

If none are available when the Solstice comes out, I'll just program one.

Sure beats rolling a Brush chart down a long hallway and looking for anomalies in a F-16 flight control computer :patriot
the newest version of the autotap cable is able to read the CAN equipped cars. you wont need to try to program one yourself. also, if i remember the newsletter correctly, all manufacturers be required by federal mandate to adopt the same pcm language by 2006(?). :D autotap, likemost obd2 scan tools do clear codes and erase logs. http://www.autotap.com/

i didnt know that about the reatta. thats damned cool. when i was a kid, i remember using the paperclip trick on my fiero to check the code #. :thumbs
 

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More answers but new questions:
Is this right? As I interpret it, their Variable Valve Timing does only that, it advances and retards the intake and exhaust cams at higher RPMs and changes overlap. There's no change in lift or duration. and it does it with the oil pressure?

I like that there's a timing chain and not a belt. That's $250 every 80,00 miles I won't be spending on a new belt.

Anybody know if that chain is driven on steel (not plastic) sprockets? I've had to replace the plastic sprockets on two GM 305's.

Also does anybody know (don't know the term) if the valve travel encroaches on the area occupied by the piston at top dead center? Honda's and Toyota's do. On their motors, if the timing belt breaks, the engine is trashed. The same would happen with a plastic sprocket.

But, I love the new info.
 

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Bizz said:
i really dont like that the water pump is driven by the timing chain.
Why not? I think it makes perfect sense!
 

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DreamerDave said:
More answers but new questions:
Is this right? As I interpret it, their Variable Valve Timing does only that, it advances and retards the intake and exhaust cams at higher RPMs and changes overlap. There's no change in lift or duration. and it does it with the oil pressure?
If it is set up like GM's other current systems it will vary at all RPM's to get the most tourqe possible and it will do it by actuators mounted to the front of the cams that are driven by the chain.
 

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2KWK4U said:
Why not? I think it makes perfect sense!
makes an electric pump probably impossible.

and, i guess it depends on how it is done. if the chain direvtly drives a sprocket or something on the pump itself, IMO it makes it unnecessarily complicated and costlier to repair and harder to replace. if you dont have to remove the chain in order to change the WP, then it would be OK since you wouldnt have to worry about throwing everythng out of whack. i mean, whats the benefit of doing it with the chain? the most common failures of a water pump, that i can think of, are worn out bearings and broken impellers. how is driving the shaft with the chain going to keep either of those from happening?

i'd rather pop off a belt, remove a pulley, loosen a few bolts, and put a new gasket and WP on than have to possibly take off every accessory in order to get the front cover off, then deal with aligning everything so the timing isnt off.

i dunno, based on what i know, i just dont like it. :jester that might change if i knew exactly how it is going to work.

EDIT: ok, i just looked up thw WP removal instructions for a 2003 Cavalier w/ the 2.2L I4 (L61). and, it isnt as bad as it could be or as bad as i thought. there was no mention of the timing chain, but there is a special tool required for the sprocket.

so, unless someone knows the benefit (dont tell me reduced NVH :D), im just not gonna like it!
 

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Bizz said:
makes an electric pump probably impossible.

and, i guess it depends on how it is done. if the chain direvtly drives a sprocket or something on the pump itself, IMO it makes it unnecessarily complicated and costlier to repair and harder to replace. if you dont have to remove the chain in order to change the WP, then it would be OK since you wouldnt have to worry about throwing everythng out of whack. i mean, whats the benefit of doing it with the chain? the most common failures of a water pump, that i can think of, are worn out bearings and broken impellers. how is driving the shaft with the chain going to keep either of those from happening?

i'd rather pop off a belt, remove a pulley, loosen a few bolts, and put a new gasket and WP on than have to possibly take off every accessory in order to get the front cover off, then deal with aligning everything so the timing isnt off.

i dunno, based on what i know, i just dont like it. :jester that might change if i knew exactly how it is going to work.

EDIT: ok, i just looked up thw WP removal instructions for a 2003 Cavalier w/ the 2.2L I4 (L61). and, it isnt as bad as it could be or as bad as i thought. there was no mention of the timing chain, but there is a special tool required for the sprocket.

so, unless someone knows the benefit (dont tell me reduced NVH :D), im just not gonna like it!
Well, for one, you can run deep cycle battery, such as an optima yellow-top or blue-top (so you can run without an alternator for longer), then run without your accessory belt all night at the track and not worry about overheating. If you really want to go with an electric pump, it'll be no more complicated a mod whether the pump was originally driven by the timing chain or the accessory belt.

If some moron neglects his drive belt and actually runs until it falls off, he can still limp home without overheating and destroying his aluminum head and/or block (not to mention bearings, etc).
 

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If you really want to go with an electric pump, it'll be no more complicated a mod whether the pump was originally driven by the timing chain or the accessory belt.
after seeing how the WP is mounted, i agree. wouldnt have figured it would be by the exhaust manifold. :)
 

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padgett said:
"...They aren't teaching basic math anymore ? (170 lb-ft at 5600 rpm = 181 hp). 4600 maybe. ...

The RPM is wrong in that article. Just Bulls**t. 170 lb-ft at 4400 rpm is the correct (about 142 hp at that point). I think the 170 hp is peaking at or around 5600-6000 rpm. Another marketing F**Khead couldn't pull his head out of his a** and listen to an engineer, I'm sure. Happens all the time...
 

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Discussion Starter #20
DreamerDave said:
More answers but new questions:
Is this right? As I interpret it, their Variable Valve Timing does only that, it advances and retards the intake and exhaust cams at higher RPMs and changes overlap. There's no change in lift or duration. and it does it with the oil pressure?

I like that there's a timing chain and not a belt. That's $250 every 80,00 miles I won't be spending on a new belt.

Anybody know if that chain is driven on steel (not plastic) sprockets? I've had to replace the plastic sprockets on two GM 305's.

Also does anybody know (don't know the term) if the valve travel encroaches on the area occupied by the piston at top dead center? Honda's and Toyota's do. On their motors, if the timing belt breaks, the engine is trashed. The same would happen with a plastic sprocket.

But, I love the new info.

You basically got it. More detailed info here http://www.billzilla.org/vvtvtec.htm

The term you are looking for is an "interference" engine. Yes, the ecotec is designed (like many OHC engines) as an interference engine. If your cam timing is far enough off, and you turn the motor over, tink-tink-tink-tink-tink-tink-tink-tink... you bend all of your valves as they kiss the tops of the piston.

I had a friend with a Quad-4 (another interference engine). (BTW, this is done to get better cylinder scavenging, flow, and for packaging reasons - I'm sure Padgett can comment). Anyways, my friend had about 145,000 miles on the car and was complaining that when he started his Oldsmobile Calais up there was a clattering sound from the area of the timing chain. My guess what the tensioner was shot (oil pressure operated), and maybe his chain/drive sprockets were worn and advised him to get the timing chain, tensioner and sprockets re-done. He went to a garage, said "ouch" at the $850+ they wanted, and took his chances.

Four weeks to the day later. He goes outside, starts his car, the clatter gets loud and the car won't start to save it's life. He cranks and cranks. Hmmm, no deal.

Sold to car to another friend that races a quad-4 in SCCA club racing as a replacement for a grenaded Q-4. Friend 2 finally pulls the motor and sho-nuff!! EVERY exhaust valve kissed the pistons and were bent by about 3-5 degrees. They looked like they were designed that way, but tear down the motor, throw away the head (with the gouged up valve seats), pistons, and I got further confirmation of my formidable remote diagnostic skills - worn timing chain, bad tensioner, chewed up main and cam sprockets from the worn chain... And the cam sprockets were off exactly 3 teeth. Apparently, this is what the chain skipped on the fateful morning.

But, like it or not, interference designed motors are here as long as DOHC configurations are around.
 
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