theoretically i guess things should last longer, with todays machining techniques, but I think the engineers also push parts harder because of this.

 

Does anybody here remember the situation with gas motors in the early 80s? The engines were detuned, consumed more fuel, and were becoming extremely complex to work on. Was that the end of gas motor performance? Yes, for a while it was. Those motors are generally still avoided for performance applications. Once the manufacters got their act together and figured out what they were doing, things have significantly improved on the performance and economy front. Now you can buy a factory 540 HP mustang. In the early 80's they were down to 140 (I think).

All said and done, Diesels are going through the same thing right now. I am hoping that it does not last the 15 years it took gassers to come back. Whenever there are massive changes to the system there is a shock wave effect. The Diesels will get it together and be great as ever. Notice I didn't say same. They will be different. To use the gas vehicle analogy again, you don't see the huge bigblocks running around again, you see smallers motors that are making great HP and getting reasonable fuel mileage to boot.

As consumers we need to stay on the manufacters to provide what the we want, but we also need to realize that federal requirements have changed and they need to meet those requirements if they want to build vehicles. If we continue to push them, they will develope the technology to meet both our needs and the requirements. Some of you need to face the facts that the 7.3 is gone. Yes it was a great motor, but it is done. Ford cannot continue to sell it in new trucks. The R&D was long paid for (I know by IH)and Ford would have loved to continue to sell it. There comes a time when it is cheaper and easier to completely design a new motor than to completely redesign an old motor. The 6.4 is NOT a new motor, it is just a significant redesign on the 6.0 in order to correct a few problems and make it 2007 legal.

Everything I have said on here is common knowledge. We all know it at some level. Some of the people on here need to actually think about the meaning of what they are saying before blurting out an opinion that makes no sense. I know many are unhappy about the federal requirements, Don't get mad at Ford, Dodge, or even GM (Ok so we can try to blame GM a little on general principle) It is not their fault, Talk to the EPA and such groups.



Rant over

 

The that is different now with diesels then it was with gassers is that power levels are not going down. They are going up, even the new DPF equipped diesels have more power stock then their older non DPF counter parts.

 

The old 12 valves peak torque was only at around 1400 RPM too. Peak HP was like 2200 RPM and 2600 RPM was the redline. Most common upgrade for 12V is to tweak fuel delivery and increase RPM redline for better power. So not sure the low RPM deal is all that big a deal. Ask anyone who tows 8000 lbs or more with their Ford, GM or Dogde diesel and they will tell you they need to run better than 2000 RPMS to tow good.
Tractor trailer have so many gears because their engines are big and heavy and their rotating assemblies can't handle higher RPM. And as you noted they have a very small usable RPM range, which also makes them more efficient, so you need to have more gears to move the loads they do. If they did not have that many gears they would need engines that were more powerful and could rev to 3000+ RPM too. which would drop fuel economy greatly.
If our light duty diesel trucks had 8 or 10 gears and our useable RPM range was 800 to 1800 RPM we could probably run lower HP engines and probably increase our fuel efficiency by 30 to 40%.

My 2 cents

 

Our trannies have a lockup TC, mileage is not EVER going up 40%. Our engines are built on the principle that they are to run as close to gasoline engines as possible. In the trucking world, redline is 22-2500. We, as diesel pickup drivers, demand that ford constantly have a HP pissing contest with GM and dodge, and this, coupled with smaller trannies not liking low end tourque, give us a high revving diesel that can live on with "my daddy is bigger than your daddy" style of reputation. Realistically, these engines need to impress owners for 300,000 and be as powerfull as the competition, other than that, is purely luck, IMHO.

 

The gripe about the new engines has been addressed over and over again - Heres how it breaks down with emissions on both the 7.3 and the 5.9.

The 7.3 was unable to meet 03' emission laws AS-IS. Even with modification it would not have been feasible. The switch to the 6.0 was purely in part of the 03' emissions and it was rushed at that! Thats why they had so many problems with turbo, egr, head studs, head gaskets, injectors, etc. The 6.4 was made again, not meet strict emission laws (and i believe partially to try and forget about the disaster they call the 6.BLOW - although not a bad engine at all, TERRIBLY POOR engineering lead to a bad reputation)

The 5.9 (a straight 6 config) is much more flexible to modify, change, and work with then the 8cy 7.3 was. This is why in the 8+ years the 5.9 never changed displacment, but did change many other things. (ex - 12valve VS 24 valve ; some would say that constitutes a "different" engine).

all in all - If ford never had to change the engines due to rising emission laws then i dont think we would have seen a 6.0,or a 6.4. There would be half the problems and double the gas mileage, These laws hurt everyone except citizens who breathe the air (you and me!). I have been to countries where there is 0 emissions laws, its sickening! would rather be a full time smoker then live there.

 

Well I am for sure we are going to see shorter lifespans. I was over at the shop that is rebuilding my 7.3 IDI, He also had a 2000 model 7.3 Powerstroke out of an International ton and half truck, the crankshaft from the powerstroke weighed half what the one from the IDI weighed. They keep building them lighter and lighter. They are trying to push mileage, horsepower, and emissions out of one engine, and its going to do nothing but get worse.

 

You are mistaken about the big rigs. You will burn one up if you try to work it at 800 rpm's. 1200 is peak torque. 1400 to 1600 will give best fuel economy. They will pull all the way up to 2000.

 

I heard some word about Dodge dumping Cummins because the engines weren't that great now. But thats just what I heard so who knows.

 

Dodge is not going to dump Cummins anytime soon. They are having some problems with the 6.7 because of the emissions garbage, but all of the big 3 are.

 

Yeah thats for sure. Cat is getting out of the Over-the-road rigs all together.

 

I'd say the EPA have a lot to answer for. They keep imposed ever more stringent standards for fuel, engine and vehicles without considering the difficulty of implementing them. Imagine where we might be if manufacturers didn't have to meet the federal requirements they do now. They could have concentrated on improving fuel economy, with the possible side affect of less emissions simply due to less fuel used. But instead they had to add egr and all the other bits to comply. Without all these bits these motors would be so much simpler and more reliable.

And let's face it. There is a lot of 6.0's getting around quite happily. And almost all the problems they have had are due to the extra bits added to comply with emissions. It would be a very good reliable engine without those bits.

Ford's change from 6.0 to 6.4 was purely to meet newer emissions standards. They had to use a DPF, which hurts performance. So they increased capacity to compensate for that. And they couldn't sell a truck with less power because we the consumer demanded more. They'd quickly lose market share.

It would be a very tough job trying to develop and produce these engines to meet ever changing emission standards and market demands. If Caterpillar are getting out of the road transport market altogether, that's a big deal indeed. Are they are that fed up with the EPA demands? Maybe it's a good thing? Maybe the EPA will realise how ridiculously difficult they are being and back down a bit. Cat might re-enter the market then?
Quite frankly the engine manufacturers deserve some slack from us. Hassle the EPA instead!

 

Emissions standards would be a lot better if the EPA helped the manufactures designing the systems, or set some kind of standards as to how the emissions. could be met. I actually e-mailed the EPA and asked them if auto manufacturers were required to have a certain type of emissions device to meet emissions. They said that it doesn't matter what method they use, as long as it meets the standards set its ok. That tells me the EPA basically says you are on your own to auto makers.

 

The reason all diesel engines are changing is because of emissions. The government is imposing harder and harder emission on diesels because there becoming more popular due to their effiencies and power. It is true the 6.4s are easy to take the cabs off. this is because anything that cant be seen under the hood has to have the cab removed to work on. such as the high pressure fuel pump. people are starting to realize how easy it is to take the cab off even to do 6.0 work. i am doing a 6.0 head gasket and a 6.4 high pressure oil pump right now. as far as maintenence, more sensors, and working on newer engines goes. there will be more sensors with newer more advanced engines. your putting down technology when it has proved how well it works in engines. look at an early diesel compared to todays diesels. no where near as reliable, or powerful. reliability is all about how well its maintained. do you drain your fuel water seperator 1-2 times a month? probably not, noone does, but if they did, there would be a lot less 6.0 injectors replaced. let technology do its thing. the new duramax is supposed to have 750 ft-lbs, and 500 hp stock. how is ford going to copmete with numbers like that without a whole new engine design and more technology?

 

Where did you hear this and what are the projected dates. I bleed blue but this has perked my interest.