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2001 HD Silverdo's - 3/4 and 1 ton
Saw my dealer today, he was happy one of his 2001
HD 3/4 ton got allocated, but my Crew Cab didn't
get picked up yet. No pricing yet either.
Any body else in line yet for a 2001?
Noticed that the 2001 Vehicle Detailed printout
lists a "Engine Oil Cooling System" for my truck.
Do all 6.0L's have one? What is it? Oil to Air,
or Oil to Water?
HD 3/4 ton got allocated, but my Crew Cab didn't
get picked up yet. No pricing yet either.
Any body else in line yet for a 2001?
Noticed that the 2001 Vehicle Detailed printout
lists a "Engine Oil Cooling System" for my truck.
Do all 6.0L's have one? What is it? Oil to Air,
or Oil to Water?
0
This discussion has been closed.
Comments
Anybody hear any more about this?
I'd like to hear your logic behind aluminum heads decreasing the compression ratio? I assume you are implying that the greater material expansion of aluminum would essentially make the combustion chamber "grow" away from the block, adding a little volume. I would be interested in seeing your theory tested, but I suspect that the accuracy of the instrumentation would limit the results, as I think any real difference would be very small, as you implied. Also, if this is the basis of your theory, I think it is flawed. If the material is expanding forcing the combustion chamber away from the piston, wouldn't the material in the combustion chamber itself be expanding also, possibly negating any change? Also, I would assume, that the heads would have a tendency to expand in the path of least resistance, i.e., they might grow longer, or wider, but not taller, where they would be fighting the tensile strength of the head bolts? Just my thoughts? I'd like to hear yours? Later.
The major advantage to aluminum heads is rooted in the great conductivity, or heat dissipation of aluminum. You can raise the maximum cylinder temperature. Thermodynamic equations show that directly effects the efficiency of an engine.
(ie. eff=[T2-T1]/[T3-T4], if you raise T2, you raise efficiency.)
This is practiced in GM's new engines. GM's aluminum head engines have just under 300 hp and get GREAT gas mileage. then look at the 6.0L from GM, it has cast iron heads. It gets right at 300 hp, and not too good mileage.
there has already been a prototype 6.0 engine built that got around 370(?) hp.
Compression ratio really has no relation to aluminum heads. Not in gasoline engines, anyway.
(silverado topic goes too fast for me to keep up)
Sorry, I was feeling lazy and didn't repost it when I referenced it. Hope we weren't too hard on Mod, my hole post was based on the assumption that he was implying the compression decrease was due to the thermal expansion. That may not have been his logic at all?
Have you heard anything more about Cummins' work on their adiabatic engine? I heard about it when I was in school. It basically sounded like the ceramic materials were still holding them back, but I wonder how it has progressed.
I am surprised thermal barrier coatings haven't shown up in production cars yet. Seems like they could use those coatings to insulate the combustion chambers/piston tops, and really increase temps and efficiency? Perhaps there are durability problems with the coatings?
Well nice talking with you. Later.
My compression statement sounds weird now but maybe it was an aluminum head motor can take more compression because it dissipates more heat? Again I'll try to find these tech articles to back me up.
Since we're on the subject of aluminum, did you guys know the Duramax diesel also has aluminum components (heads and intake manifold, among others)? Heat dissipation is NOT what you want in a diesel, when they're trying to run solely on compression. Can't wait to see the long-term effects of THAT decision...
kcram
Co-Host - Smart Shopper & FWI Conferences
edmunds.com Town Hall
Although I've argued many times with you and others about the equal capabilities of IFS 4x4, everyone waiting for the new GMs were hoping for solid axle. Its what the public wants. I think the success of the new GM HD lineup will hinge on just how good the Duramax is--the diesels made Ford and Dodge, and killed GM in the 90's. I think the diesel is much more of metric than 4x4, to Joe Public.
I'm confused by your point about saying dissipation is not what you want in a diesel. Can you explain that. My learning is that quicker dissipation allows you to raise cylinder temps without endangering overheating, raising efficiency. Compression creates combustion temp...is that what you are saying is detrimental?
Re: You June 9th. disinformation- gram
Subject: Truck engineering
Your premise that the solid front axle is the ONLY legit choice for the HD 4x4
commercial truck buyer just ain't so in the experience of many sad Dodge Owners.
I admit to having been one. Had both a 1-ton and a 3/4 ton. The one ton had all factory equipment for suspension. I call it, "the big bent hunk of steel with tires at each end". Suspension?? No!! Punishment for the rest of the front end assemblies, including steering gear box and all other steering components, engine mounting, exhaust headers.
My 1-ton had the steering box rewelded to the frame member so many times that
it looked like a plastic surgery mistake, a real bad one. The rear end was just as bad. It didn't track, like a truck should, it hopped side to side at the
slightest provocation - just like the front, except the front did a lot of damage along the way. There are 100's of thousands of Dodge Owners who have suffered these same problems.
On my 3/4 ton, I had a Pathfinder four-wheel drive set-up installed before it
got shipped to the dealer. They cost a small fortune but it did help the front end problems considerably. Unfortunately, not the rear. kcram. Do your homework. It's obvious you're in love with your truck. Strongly suggest some
therapeutic intervention. A good Therapist can. help you ... it's not too late.
As to diesel engine design, the Japanese use of steels has been world renowned
for many years. Look back to the famous Zero. Not diesel, but a tremendous piece of engineering excellence that obviates kcram's heat dissipation theory.
Obviously he doesn't really know too much about diesel engineering. He's quite
correct when he asserts that heat dissipation (in a general, overall, sense) is
not what's looked for in diesel engine design. BUT, these designers who put the Duramax engine together are about a Shak and a half above kcram in their intimate understanding of just how to get the proper power band out of that engine in and under all conditions of operation. They know so much about this
stuff that for an unschooled, non-expert nay saying negativist to challenge their engineering equations and final decisions (after lots of testing) is asinine. Sorry kcram, your guesses will remain just that and it my belief
that time will prove the Duramax folks know what they are doing and, unlike
yourself, what they're saying about the engine.
In a tricky situation, with a diesel for transportation, I'd far prefer to have
one of them along that have you scratching your heads when something went wrong.
Hey, get a good truck and RELAX Big Guy.
Yours for Happy, (Safe) Truckin'...
DAVE-40 SUPREME COMMANDER, U.S. TRUCK FORCE
I have a 1996 Ram 3500 Club cab Cummins 4x4, as you probably remember. My dad has a 1985 W350 4x4 at his job. Both trucks have had NO front suspension problems, and I can tell you firsthand, I have jumped curbs at speed in both of them. I've never had a steering box or engine mount problem. I've replaced the front shocks twice and the steering stabilizer once in 60,000 miles. My town's Public Works department stopped buying GMC 3500 4x4s because of the IFS - they now use Ford F350s and Dodge 3500s. These are trucks that have to be good to go 24/365. The GMC 4x4s we do have are used as Board of Education service trucks, usually hauling office furniture or landscaping equipment. You had some bad Dodges - I had some bad Fords. That's 4 trucks between us out of how many million? But from my own observation, there are way more Super Duty Fords and HD Rams around here in north NJ than HD Chevy/GMC trucks. The commercial buyers of 4x4s are speaking with their dollars.
For the record, I'm far from an unschooled negativist. Having suffered through several YEARS of thermodynamics and other engineering courses in college, I'll stick by my comments regarding aluminum heads in the Duramax. As we all agree, a diesel runs solely on heat from highly compressed air. Cast-iron will maintain that heat, allowing the diesel to operate more efficiently by not requiring the cylinders to constantly recover the operating temperature. When I say "efficiently", I'm not referring to miles per gallon; instead, the completeness of the combustion process. Aluminum heads run the risk of allowing too much heat to escape from the cylinders causing a less than perfect burn of fuel, not to mention the unnecessary transfer of that dissipated heat to the engine compartment. Ask anyone who runs a diesel in hard winter areas if they want their engine cooling off even one degree - the grille is covered for a reason. As for the Japanese examples you bring up, steel is an iron alloy - aluminum is aluminum. Why bring up an example that is not a diesel? Aluminum heads work very well for gasoline engines - heck, ALL-aluminum engines work very well with gasoline. But stop by a class-8 trucking company and ask them if they would buy new rigs with aluminum diesel engines.
Years of testing are just that - years of testing. What designers plan and what happens in the real world often do not gel. I will be the first one to admit that those "years of testing" meant jack for Dodge's front brakes. I'm on my fifth set of front pads, and still the original rear shoes. "YOT" told Ford their new OHC engines were state of the art - all three have been redesigned, and upgraded in power and torque in just 3 years.
Don't get me wrong - I really hope the new HD Silv/Sierras are competitive. That will make Ford and Dodge better as well - I'd rather have a full compliment of manufacturers to choose from. But if the new GM trucks don't match up to the other 2, then what did the General accomplish? It's not that their designs can't work - it may simply be that their designs aren't wanted by the market.
We agree to disagree, dave40
kcram
Co-Host - Smart Shopper & FWI Conferences
edmunds.com Town Hall
As far as the IFS/Solid axle debate, there is certainly a place for both. In an ideal world a solid axle would be a no cost option on the GM trucks, for those who want/need it. Since we know the world isn't ideal, we have to make compromises. As a GM guy, IFS wouldn't be enough to make me go buy a solid axle Ford. I think the past combination of a weaker diesel and IFS did hurt GM sales, but I would agree with cdean or whoever, that said the engine is probably more important to most, and the IFS will be rationalized by us GM freaks for the better ride.
Hopefully, the Duramax will be great, aluminum heads and all, and we will all have three great brands to chose from.
I agree with Roger about the efficiency. But I think KCram was getting at something different.
GM Front IFS - I was a big skeptic going in when purchasing my '99 about the GM front end. My one memorable experience with my Silverado 1/2 ton 4x4 was driving along the Arizona Trail with the back of the pickup loaded with about 1,000 lbs of firewood. It was getting dark and shadowy and I was going too fast and ended up hitting a bowling ball sized rock with the left front end. Amazed that I didn't break the front steel wheel or blow the sidewall out of the LT245 tire, but it held. Still have a bump atop my head from the launch. Thought for sure I'd have to realign the front end but so far (15k later) still tracks true and the tires are looking perfect. Now the bad part of the story. The frame flexed so much that the left front corner of the bed dented in the cab about like a baseball sized dent. I'm so pleased with the toughness of the front IFS (ya, I know I'll put in 1/2 shafts every 5 years or so) that I'm glad my new 3/4 HD 6.0L Silverado will have it....
Did I mention that Isuzu makes crappy diesels ;o)
I believe your last sentence in your first paragraph is closer to the actual reasons of my experience.
markbuck,
Kinda funny, no matter what the subject, seems like someone has had a bad experience. You're the first I've heard that's had a bad one with Isuzu. My experience talking to Isuzu diesel owners/operators is that they are excellent engines. I've talked to three owners of the mini diesels in their compact trucks and Troopers that have had excellent experiences for 150k to 500+k miles. I have had the unpleasant experience of sitting in two different tow trucks taking crippled pickups home (one bad collision with a big mule dear, and one thrown rod in an old ford 351) where the tow truck had Isuzu powerplants. Both tow truck operators loved their Isuzu diesels. It also seems like everything else you hear about them is positive. It will definitely be interesting to see, because I'm guessing the performance figures that have been reported are accurate, the only question will be durability.
I know they make LOTS of diesels all over the world. most all are heavy duty apps.
People will ALWAYS argue against the IFS. i've argued for it around here for a while and have always met stiff arguements. Not that they aren't valid, but I think Markbuck's story represents the worst case scenario. And i think the IFS has gotten to the reliable stage, in fact i think it has been there. late 80's, early 90's, yes there were quite a few failures, they just weren't strong enough. but they have been tweaked and improved a couple of times. I have 3 friends with '94 z71s ( all around 150k miles) that all spend a LOT of time off road, pulling cattle trailers, general rough ranch duty...no probs whatsoever. The biggest downside i can see to IFS is that you always need to keep an occasional eye on the boots to make sure they aren't torn....solid axle you don't have to think about ever.
If the aluminum head is liquid cooled, there must be excessive heat. If not, why bother cooling it?
Dave40,
I agree about the IFS. As long as you can get those solid front axles in the other makes, good to have a choice. I prefer a good ride for the times I'm not running over bowling ball sized rocks.
Markbuck,
15,000 miles later and you still have the bump on your head....better slow down some.
About the Isuzu diesel:
A friend of mine who owns a Powerstroke says the Isuzu diesel is the cat's meow. While I don't know, I do notice it seems lots more quiet in those medium/heavy duty commercial trucks than the others. Could disappoint those seeking attention.
Well, my only way to get back is BADMOUTH the heck outta ISUZU. How come none of yawl heard about the Isuzu screw up but we all know about GM's first 4speed tranny problem, and the problems with Ford Pinto's and......
Too bad you had the problem, but I don't know how that problem relates to the new Duramax since it is a new engine employing their well-recognized engineering talent in the medium/heavy duty applications, and GM will be handling the warranty.
If anyone is interested here are the prices for the 2001 GM Hds.. More to come as www.TheDieselPage.com gets all the info converted into HTML..
http://www.thedieselpage.com/duramax/prices.htm
See ya,
Steve O
Still no allocation for mine at our local dealer.
DETROIT -- General Motors' new Vortec 8100 V8 engine is about to be unleashed as the new industry standard in gasoline engine authority in the heavy-duty pickup market. This 8.1 liter powerplant will supply class-leading energy to the 2001 Chevy Silverado and GMC Sierra 2500HD/3500 pickups, putting the power majority in GM's work trucks.
Targeted horsepower and torque ratings are 340 hp @ 4,200 rpm and 455 lb-ft @ 3,200 rpm, respectively. A ZF S6-650 6-speed transmission is standard while an all-new optional Allison 1000 Series automatic transmission features advanced shift capabilities that take heavy-duty, shift-on-its-own truck driving to new levels of satisfaction.
GM Powertrain engineers used the proven Vortec 7400 as a basis for creating the new engine and focused on only those changes that would provide real customer benefit. As an example, they were able to maintain the Vortec 7400's same general envelope size and still get more power/performance. The larger displacement comes from the longer stroke (total length - 4.37 inches) used in the 8100. The same bore size has been maintained.
A 50 percent increase in ignition energy, a reduction of emissions and an improved idle quality are advantages gleaned from the coil-near-plug ignition system.
Internally balancing the crankshaft led to a reduction in its stress by removing the counterweight from the flywheel. There's a new firing order that provides an additional 7 percent decrease in crankshaft stress.
The cylinder heads have been redesigned to create replicated ports for the combustion chamber. This common-style porting and porting length minimizes the variation in torque from one cylinder to the next, producing a much smoother operating and cleaner engine.
Even-length runners in the intake manifold are used for each cylinder to create more even combustion and greater efficiency in the combustion process. The fuel rail system is part of the manifold itself, creating an integrated air/fuel module. The throttle body now sits front and center on the intake manifold, where it can distribute the air more efficiently and also enhance engine package ergonomics.
The technological envelope of piston and ring design was expanded in order to allow the Vortec 8100 to provide its many best-in-class power, performance and reliability/durability benefits and package efficient size. The new pistons have a much shorter combustion height and a tighter ring pack than those in the average engine.
The 8100 uses cast stainless-steel exhaust manifolds, a first for GM 3/4-ton and 1-ton truck engines. This material withstands higher temperatures better than cast iron exhaust manifolds and is more durable and longer lasting.
Cooling system enhancements include quick connections that replace compression fittings throughout the engine/transmission oil cooling system for enhanced durability and easier assembly. Radiator hose ends are specially formed and provide tighter, more reliable and durable fits. Special beads on hose inlets and outlets ensure tight fits and lessen the chance of leaks or hose blowoffs.
Like its big block (Mark engine) predecessors, the Vortec 8100 will also serve highly demanding marine and industrial applications, powering everything from boats to irrigation pumps and generator sets (when used as a stationary engine). It's a testimony to the gutsiness of this engine that it can successfully compete in these segments, going head to head with diesel engines. The Vortec 8100 also meets industrial customers' special needs for being able to run alternative fuels, like propane and compressed natural gas.
Marine application testing is a more strenuous procedure for validation. Because about 25 percent of Mark engines are typically sold for marine use, much of the validation on the Vortec 8100 was done using the marine market's more severe-duty test parameters. In one particular test, called the "Marine Dock," an engine is run at wide-open throttle for 300 hours straight, further proving the mettle built into this motor.
Vortec 6000
The base engine for these heavy-duty trucks is the Vortec 6000, the top mill offered in the lighter-duty Silverado/Sierra. It's been improved for its use in the 2500HD/3500.
With a targeted power rating of 325 hp at 5,000 rpm and 370 lb-ft of torque at 4,000 rpm, it has a stout 70 more horsepower and 40 more lb-ft of torque over the 5.7 liter it replaces. A 5-speed manual transmission, now mated to a larger, more durable pilot bearing, is standard. The proven 4L80-E automatic remains an option.
More efficient aluminum cylinder heads are better flowing, 56-pounds lighter and have improved valve-seat durability. They also dissipate heat more quickly, reduce overall cooling requirements and allow an increase in spark advance without pre-ignition.
The deep-skirt cast-iron block has six-bolt main bearing caps, which help in the overall rigidity and the reduction of noise, vibration and harshness (NVH). There's also a new firing order that reduces stress by 7 percent on the internally balanced and counterweighted cast nodular iron crankshaft.
A new camshaft has more lift, less duration and more overlap for improved airflow. Its main benefit is increased fuel economy, but performance improvements are also garnered with the addition of a lower-restriction exhaust system. A coil-near-plug ignition system delivers a 50 percent increase in ignition energy, helps reduce emissions and improves idle quality.
With all this and alternative-fuel capabilities (compressed natural gas or liquid propane gas), the Vortec 6000 is a very powerful, innovative and versatile standard-equipment engine.
An advanced coolant loss protection system protects both engines in the event coolant drainage, either partial or total. If a loss is detected, the computer limits engine power and allows the engine to run as an air-cooled system, giving the driver the ability to find a repair facility or suitable pull-off area.
The Vortec 6000 and 8100 answer the customers' desires for more powerful, efficient, durable, smooth and reliable engines. They not only raise the bar for heavy-duty truck gasoline powerplants but also make a statement about GM's best-in-class intentions for the 21st century.
DETROIT -- An all-new Duramax Diesel 6600 engine will debut as an optional engine in GM's 2001 Chevy Silverado and GMC Sierra 2500HD/3500 pickups, Crew Cabs, Big Dooley and Chassis-Cab models, next year. It is positioned to help GM set new industry standards for diesel power, performance, durability/reliability and quiet operation in the growing heavy-duty (HD) pickup class.
The new Duramax Diesel 6600 is the product of a joint venture (DMAX Ltd.) between GM and Isuzu Motors, and it's the second in a growing family of GM-branded Duramax engines. The first was the Duramax 7800 (7.8-liter) engine, which became available in the 2000 model year of GM medium-duty truck models earlier this year.
GM's relationship with Isuzu began in 1971 and was strengthened in 1997 when GM announced that Isuzu would develop diesel engines for GM. Because of Isuzu's expertise in commercial vehicles and diesel engines, the company plays an important role in GM's global strategy. They have produced and sold more than 60 million diesel engines over the past six decades, and they enjoy a solid reputation for reliable and dependable performance. This expertise is being counted upon to help GM establish a dominant position in the diesel-powered full-size truck market just as the Vortec family of gasoline engines has done.
Duramax Diesel engines will be sourced and manufactured through a brand new manufacturing facility in Moraine, Ohio.
Duramax Diesel 6600 Availability
The new Duramax Diesel 6600 will be available as optional equipment on 2001 Chevy Silverado and GMC Sierra 2500HD/3500 Series pickups, including Crew Cab, Big Dooley and Chassis-Cab models. These new trucks are scheduled to debut during the fall of 2000.
When specified, the Duramax will be mated to either a ZF 6-speed manual transmission (std), or an all-new 1000 SeriesTM 5-speed automatic transmission (opt) from Allison Transmission.
Additional Duramax 6600 applications are planned for other GM truck products, and announcements regarding those will be at an appropriate time in the future.
Duramax Diesel 6600 Features and Advantages
Totally new, 90-degree, direct-injection, overhead valve (OHV) four-valve-per-cylinder turbocharged diesel V8, with aluminum high swirl cylinder heads and significantly improved cooling characteristics.
The Duramax 6600's four-valve-per-cylinder configuration is the standard for modern diesel engine design. It optimizes airflow in and out of the engine, improves breathing at higher rpm's, processes more air and, therefore, generates more horsepower than competing designs.
The Duramax 6600 has a slight twist to the shape of its valves relative to the centerline of the crankshaft. This gives incoming air some added swirl, which is important in the combustion process to controlling emissions and maximizing fuel efficiency.
To further maximize efficiency, the Duramax 6600 incorporates a number of cooling techniques:
Charge air cooler. The center-mounted turbocharger on the Duramax pulls fresh ambient air in through the air cleaner and into its compressor. After being compressed, the air is then channeled through a duct to the charge air cooler (which is packaged like an additional radiator in front of the water radiator). The cooled air then travels through the intake manifold and into the engine. This cooler air is denser, so it provides more power. A secondary result is reduced combustion chamber temperatures a major factor in GM's extended engine durability strategy.
Integral oil cooler. The Duramax's integral oil cooler is like those found on many medium-duty truck engines. Instead of being located in the radiator end tank, it is mounted on the side of the engine. All of the water flow from the gear-driven water pump is channeled through the oil cooler before it goes through the engine. The result is increased oil cooling and extended engine life.
Piston spray cooling. Pistons have to absorb the full shock of thermal loads and high combustion pressures both of which are much stronger in diesel engines than those found in the typical gasoline engine. For that reason, the Duramax has a piston spray cooling system that sprays oil directly onto the backside of each piston bowl. The added cooling that this system provides adds to reliability and durability.
Transmission oil cooler. This new transmission oil cooler, used with the Allison 1000 5-speed automatic transmission, is mounted below the radiator to preclude heat from the transmission going into the engine cooling system. It relies on RAM air from openings in the front bumper. The size of the cooler has been increased from previous models, and its larger 5/8-inch lines (compared to 3/8-inch lines previously used) provide for a very liberal 6-gallon-per-minute (GPM) transmission fluid flow rate. Transmission fluid cooling is substantially improved as a result.
Larger 21-inch-diameter composite fan with larger modulating clutch and a 2-piece fan shroud. The benefits of a larger fan are almost too obvious to mention it simply pulls more air through the radiator. The larger modulating fan clutch reduces fan noise, and the 2-piece fan shroud allows for easy service.
Best-in-class power/performance with the segment's highest horsepower and peak torque ratings. Targeted ratings are 300 horsepower @ 3,100 rpm and 520 lb-ft of torque @ 1,800 rpm. Its high, flat torque curve will deliver more power across the power band than any competitor, and will help Duramax 6600-equipped GM HD pickups excel in off-the-line performance, acceleration and heavy-duty trailering and hauling.
Best-in-class durability and reliability. The Duramax 6600 has a targeted operating life of at least 200,000 miles without any major component failures. Key durability enhancements, in addition to all of the enhanced cooling features previously mentioned, include:
A nitrided crankshaft. Nitriding has proven to be one of the most effective method of guaranteeing crankshaft dependability over time.
A deep-skirt block design, with side-bolted main bearing caps for increased strength and structural rigidity. The deep-skirt design was optimized using Finite Element Analysis (FEA) to enhance engine balance, make the structure more rigid, and provide smoother, quieter engine and driveline operation.
An induction hardened block. It's an exclusive for diesel engines in this class.
Hardened valve seat inserts in the aluminum cylinder heads. Another exclusive for engines in this class, they provide better durability and reliability, as well as improved serviceability.
A gear-driven water pump with metal gears for more robustness is another new feature that's common to medium-duty truck engines. In most engines, the water pump is driven by the fan belt. This gear-driven design reduces stress on the accessory drive belt, and it also means that a customer will not be stranded if the drive belt fails.
Significantly improved fuel economy. Duramax 6600 engines will be much more efficient than previous GM Diesels. They offer significantly improved fuel economy (specific fuel economy is 15-20 percent better than GM's current 6.5 turbo diesel, for instance), particularly at highway speeds. This big improvement in fuel efficiency was principally achieved with:
The engine's new lightweight design. The Duramax 6600 weighs only 836 lbs. (379 kg) thanks to the use of aluminum in key components like the cylinder heads, crankcase, accessory drive brackets, intake manifold and flywheel bell housing.
The engine's new Bosch direct-injection, common-rail fuel system, which provides maximum power for each pulse of fuel used.
Best-in-class operating quietness and smoothness. The new Duramax 6600 posts noise, vibration, and harshness (NVH) figures more typical of similar-sized gasoline engine. This astounding improvement is due to many of the structural enhancements previously mentioned (deep-skirt block design, casehardening of the block, one-piece aluminum crankcase and one-piece aluminum bell housing), as well as the Bosch electrically-controlled fuel-injection system which allows full authority in injection timing and quantity.
Easy serviceability, created in part by:
The engine's compact size. It's shorter and narrower than any of the competitors' diesel engines, allowing for easier access to external components. For instance, the Duramax is 34.5 in. long (878mm), compared to Ford's at 35.2 in. (896mm) and Dodge's at 38 in. (967mm).
The placement of the turbocharger in the "V" space atop the engine. This space is normally not used by competitors, despite the fact that it allows for better packaging efficiency.
The thoughtful placement of items such as: the timing gear train (located at the front of the engine), an easier-access oil filter (located at the lower left rear corner of the engine) and the fuel filter (located at the upper right rear of the engine). All are easily accessible and reduce service time.
Duramax Diesel 6600 Fuel Delivery System
The direct-injection fuel system on the Duramax 6600 has been mentioned several times in previous paragraphs. However it is different enough from other direct-injection systems that it is worth talking about in more detail. The system was developed by Robert Bosch Corp., the industry leader in diesel fuel-injection systems.
Direct-injection means the injector sprays fuel directly into the combustion chamber, which allows for more efficient combustion. In addition, the electronic common-rail system adds a new dimension to diesel fuel control over its mechanical predecessors. For the first time, pressure generation is decoupled from and independent of engine speed and the injection event. Engineers can now program the system for optimal performance over the entire engine speed range, and achieve new levels of economy, emissions and driving comfort under all conditions. What makes the Duramax 6600's fuel delivery system better than most other systems is the strategy and technology used to deliver fuel to the injectors
The fuel is drawn from the tank by the low-pressure pump through the Electronic Driver Unit (EDU). The fuel cools the electronics, which have the arduous task of actuating the solenoid valves in each injector, sometimes over 25 times per second! The EDU works in concert with the Engine Control Module (ECM) to provide a strong, precise signal for each cylinder's combustion event. The EDU also controls pressure in the fuel rail to ensure that it will be correct for precise fuel metering.
From the EDU, the fuel passes through an engine mounted fuel filter. This filter has a water sensor, a water separator and a fuel heater. If necessary, the heater warms the fuel to 14 degrees C to prevent any waxing of the fuel.
The fuel then goes to the Bosch high-pressure pump. If the ECM and EDU are the brains of the system, the Bosch high-pressure pump is clearly the heart. It sends the fuel to the fuel rails, variably controlled at pressures up to 23,000 psi, where it is distributed to the injectors at each cylinder.
The injector, with a constant injection pressure fed to it, can now open, stay open and close as directed by the ECM and EDU, depending on various sensor inputs, to achieve effective combustion for the conditions present. The injector is optimally located in the cylinder head, and configured with a custom-designed spray pattern matching the combustion chamber, to gain most efficient combustion. This in turn enables improved fuel economy, lower emissions and less heat loss and rejection.
The sophistication and technology of the system components make the Duramax capable of employing a process known as "pilot injection."
Pilot injection involves injecting a small amount of fuel into the cylinder prior to the main injection event. A complex process in the electronic controls selects the optimal time, duration and quantity of pilot injection, coupled with the main injection charges. As a result, combustion starts on a smaller scale and builds subtly but rapidly for reduced noise/knock, less vibration and quieter, smoother warm-ups.
Summing It All Up
GM's current benchmark status in full-size pickups, Isuzu's in diesel engines, Bosch's in fuel injection and Allison Transmission's in commercial-duty automatic transmissions all combine to ensure that next year GM's Duramax Diesel-powered HD pickups will achieve benchmark status in the full-size diesel pickup segment.
Dave-40s pick
What I can afford!
The day is near.
- Tim
4WD on snow covered concrete can be harsh..but forgiving in the rear....but all 4?.....yikes!
- Tim
On the 2500 it calls it, "Autotrac Active 4WD Transfer Case" with a code of NP8 and an invoice price of $322.
Both say the transfer case is a "New Venture 261."
Does anyone know anything about this?
the new actual HD line can't be much more HD for a 3/4....I don't see why they wouldn't offer it...course who knows GM
- Tim
The 2001 GM Silverado HDs will have 4 different Transfer cases..
The 2500HD (9200lb GVW) will get the NV261HD for the Manual shift Case,
If you opt for the Electric shift case it will be the NV263HD..
The 3500s and 3500 Chassis Cabs will get the NV261SHD for the Manual shift case, if you opt for the Electric shift case it will be the NV263SHD.. I think you can figure out what HD and SHD is for yourself..
The NV261HD and NV261SHD share almost NO parts what so ever.. The same for the NV263HD and NV263SHD..
Steve
this topic is being "frozen." It will be archived or deleted in the next 10 days or so.
Front Porch Philosopher
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