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2001 HD Silverdo's - 3/4 and 1 ton

markbuckmarkbuck Posts: 1,021
edited March 2014 in Chevrolet
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?


  • markbuckmarkbuck Posts: 1,021
    Looks like still a peak of 300 hp but at a lower 4400 rpm. Maybe with the AL heads, rather than make more HP they went for a little more of an RV cam and timing and are making the same 300 hp at 400 rpm less, which means torque is up about 8% at 4400 rpm if I do my math right.

    Anybody hear any more about this?
  • cdeancdean Posts: 1,110
    haven't seen that. Are there any published figures or graphs for the 2001 GM engine lineup?
  • roger350roger350 Posts: 157
    I was just looking on the GM Fleet Preview site, that was posted a while back on the Silverado thread. They are still listing the 2001 6.0L power figures as: 370 ftlb @ 4000 rpm and TBD hp @5000 rpm. Furthermore, they are listing the compression ratio as 9.5:1, as opposed to GM Powertrain listing for the 1999-2000 of 9.4:1. Where are you getting your information markbuck? I hope the 325/370 comes through for the 2001, but I would be very skeptical of any information out there right now. Either way, it is a small change, but I figure we better be getting something out of those aluminum heads, besides possible durability problems! Otherwise I'm going to wish I got one of the 2000's all iron engines.
  • modvptnlmodvptnl Posts: 1,352
    Why would aluminum heads give any performance gain?? Unless they redesigned the ports or something aluminum actually lowers the compression ratio a tad when heated up. It is way easier to port and machine but I don't see us doing that on a brand new truck.
  • vince4vince4 Posts: 1,272
    More HP because the heads dissipate heat better so they can advance the spark more.
  • roger350roger350 Posts: 157
    Vince4 nailed it, the better heat dissipation allows slightly more spark advance. I think most of the power is actually coming from a new cam though, or at least that is what I have read. Don't ask me where, as I read about every car/truck magazine I can get my hands on.

    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.
  • cdeancdean Posts: 1,110
    Actually Mod, thats not correct. I'm not sure what your theory was about reducing the compression ratio, but if you think its due to greater thermal expansion, thats incorrect. Material engineering has come leaps and bounds over the past 5 years, and manufacturing engineers are now able to produce an exact metal matrix (alloy) that will perform (expand) exactly like they predict it to.

    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.
  • cdeancdean Posts: 1,110
    i meant to say the prototype 6.0 engine was built with aluminum heads.
  • cdeancdean Posts: 1,110
    Could someone post the GM Powertrain Preview site for me?

    (silverado topic goes too fast for me to keep up)
  • markbuckmarkbuck Posts: 1,021
    Saw it on the Chrome website, but I'm locked out now. They were the one's claiming 300hp at 4400rpm. No torque figures.....
  • roger350roger350 Posts: 157

    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.
  • modvptnlmodvptnl Posts: 1,352
    that I can't stand when people say something and can't back it, which is what I'm doing. I searched for a little while for the technical article I'm recalling but can't find it. I will keep searching. My recollection is that because of the heat dissipation all things being equal an iron head will make more power. We want as much controlled heat during the combustion process as possible. Heat is an enemy only during uncontrolled burns or hot spots in the chamber.

    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.
  • KCRamKCRam Mt. Arlington NJPosts: 3,516
    I have to admit, I'm very disappointed that the HD Silv/Sierra will maintain the independent torsion bar suspension on 4x4s. It was a mistake in 1988, and it's still a mistake 13 years later. Expect Ford and Dodge to remain the choice of HD 4x4 commercial-truck buyers, thanks to the solid front axle, and proven diesels.

    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...

    Co-Host - Smart Shopper & FWI Conferences Town Hall
  • cdeancdean Posts: 1,110
    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 that what you are saying is detrimental?
  • dave40dave40 Posts: 582
    To: kcram and those who think alike
    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'...
  • KCRamKCRam Mt. Arlington NJPosts: 3,516

    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

    Co-Host - Smart Shopper & FWI Conferences Town Hall
  • cdeancdean Posts: 1,110
    Point about the dissipation problem is well explained. I never really thought that the speed that things run internally that the split second that the high heat is generated (by compression) would escape so quickly. Kind of a whole different frame of reference I guess. hopefully Pop-Mech or someone will do an article on it. Kinda curious.
  • roger350roger350 Posts: 157
    I believe that aluminum heads are used in gas engines to allow higher combustion temperatures, without completely frying parts? The theory is that the temps can peak higher, but then the aluminum will draw the heat away more quickly, eliminating hot spots, burned valves, etc. I see no reason why this isn't an advantage for a diesel also? If it allows higher peak combustion temperatures, without killing parts, then it is an advantage. I remember just enough thermo to be dangerous, so I'll be the first to admit I could be wrong on this stuff. I do recall an adiabatic engine, one with 0 or very little heat loss, would be the most efficient. But doesn't the difference in intake temp vs. combustion temp factor in there somewhere? If so, then the higher peak temperatures allowed by aluminum would be an advantage. But efficiency would still be best if all of the heat was contained in the cylinder and converted to mechanical energy, so I'm not sure? Time to crack out the old text books!

    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.
  • cdeancdean Posts: 1,110
    its Monday and i don't feel like thinking thermo this morning, so i'll try this angle: isn't this Isuzu engine from their current engine technology? I think they are bringing something proven to the market, unlike what GM(new pumps) and Ford(Ps) did in '94 (Ford's worked, GM's didn't).

    I agree with Roger about the efficiency. But I think KCram was getting at something different.
  • markbuckmarkbuck Posts: 1,021
    Isuzu diesels are junk. I have one experience with a broken crank and rod as my 40,000 mile "forever designed" diesel. Then Isuzu failed to back it with any type of warranty past the end of the 36k factory warranty. BTW, did I mention that I think Isuzu diesels are junk?

    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)
  • modvptnlmodvptnl Posts: 1,352
    This months Mustang and Fast Fords in one of their tech articles simply states that iron heads will produce more HP then an aluminum head. Sorry I can't be any more scientific then that. I do know from years of being around building engines that when a company like TFS or Dart makes the same head but in different materials the iron head will be more efficient out of the box. The head grinders I know prefer aluminum because it's repairable and waaaaay easier to port.

    I believe your last sentence in your first paragraph is closer to the actual reasons of my experience.
  • gwmooregwmoore Posts: 230
    Seems like IFS is newer technology. With all newer technology, some things need to be worked through and cutting-edge high performance applications use the technology first, while dependability-reliant uses follow sometime later (jet engines in airplanes, disk brakes, abs brakes, etc.). Yes, at first IFS was worked through for light applications (sports cars, coups, sedans) and questionable for heavy duty applications. But trial/error/advancements will catch up. Hopefully the new HDs will be the generation where the strait axle is left behind IFS. I personally like the lower center of gravity and better ride/handling of the IFS, as long as the truck can carry my camper. The better the clearance and wheel travel, and the lower the center of gravity at the same time, the better. Look at the Humvee, IFS allows a heavy duty suspension, maximized clearance, and an incredibly low center of gravity. IFS is definitely not a drawback to me in a new HD, rather it is a positive if it works. In a few months we'll know if the new suspension does.

    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.
  • cdeancdean Posts: 1,110
    i've only talked to one guy who's ever operated an Isuzu diesel, and he worked for a fleet. He swore by them.

    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 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.
  • quadrunner500quadrunner500 Posts: 2,728
    If the aluminum head is liquid cooled, there must be excessive heat. If not, why bother cooling it?

    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.

    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.
  • z71billz71bill Posts: 2,000
    Several of the trucks at my job have the Isuzu diesel engine, the oldest one has 350,000 hard stop and go miles (most with a load of about 15,000 pounds) - has never had a problem. The rest of the truck looks beat to hell, but the engine runs great.
  • quadrunner500quadrunner500 Posts: 2,728
    Apologies for mis-spelling Kcram....Ouch!
  • markbuckmarkbuck Posts: 1,021
    That my '86 trooper was Isuzu's first attempt at a turbo diesel in a regular sized vehicle. Two years after I dumped the thing, I get a letter from ISUZU that they screwed up something about the design, and were offering an extended warranty and/or rebuilt motors to CURRENT owners. Laughed at me when I called and asked for a refund on my $2100 long block expense....

    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......
  • gwmooregwmoore Posts: 230
    Probably didn't hear about the problem because Isuzu has a tiny presence in the US, other than heavy duty applications. I tried to find one of the diesel troopers about 7 years ago because I heard good things about them from a couple different owners, but I only found one for sale at the time in my area. The problems with GM, Ford & Chrystler affect a heck of a lot more people.
    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.
  • sovercash1sovercash1 Posts: 112

    If anyone is interested here are the prices for the 2001 GM Hds.. More to come as gets all the info converted into HTML..

    See ya,

    Steve O
  • markbuckmarkbuck Posts: 1,021
    Looks like I'm at around $28K MSRP for the 3/4HD 4x4 CC LB stripper. Figure with dealer inv discounts then adding back options, will be about $27.5K plus TTL....

    Still no allocation for mine at our local dealer.
This discussion has been closed.