Experience with new SCR engines?

Discussion in 'Trucks [ Eighteen Wheelers ]' started by Oram, Sep 8, 2012.

  1. Sportster2000

    Sportster2000 Road Train Member

    Messages:
    1,023
    Thanks Received:
    236
    Joined:
    Jan 5, 2008
    Location:
    Indiana
    First off if a fault was set and a derate occured and then went away an inactive fault would appear in the system. These fault codes just don't magically dissapear by themselves.

    The second part of your statement of these "companies" racing the engines off to market after they have a prototype is completely wrong. They have around 4 years to design, test, prove, and certify an engine to sell it. As for the perfect conditions you speak of I have not seen them. I have seen a temperature change of 178 degrees F in a semi. There are people out there that do stuff to a truck you wouldn't think of doing just to try and break it.

    For the last part which I have not qouted you on, if they are less efficient then how can one of these "less efficient" trucks get 8.5 to 9 mpg loaded?
     
  2. dpfndefbad

    dpfndefbad Bobtail Member

    Messages:
    35
    Thanks Received:
    2
    Joined:
    Oct 31, 2012
    Location:
    PA
    You state the epa required manufactures to use scr and dpf. You are wrong again. Epa requires emissions meet a certain threshold at the exhaust pipe. However this happens is not mandated by any government agency. Cummins and other manufacturers chose the scr and dpf probably because it was the cheapest technology that was available. I mean with my truck stop intelligence I deduced this but hey maybe big business would choose whats best instead of whats most profitable. If you believe that I have some magic beans I will sell you.
     
  3. dpfndefbad

    dpfndefbad Bobtail Member

    Messages:
    35
    Thanks Received:
    2
    Joined:
    Oct 31, 2012
    Location:
    PA
    The derate never went away. The first time cummins told me they didnt know why it derated. They did a computer forced regen and I went on my way for another 50k miles. Second time it derated was 5 months later and I had it towed to cummins. Said it was nox sensor..replaced did update on ecm and I got 15k miles before the third derate. Got it into a parking lot and waited for cummins tech. He came he saw he did a computer forced regen and i drove it to their shop. 2 days later I came to pick it up. Service manager and tech both told me they had no idea why it derated and all their diagnostics indicated evertyhin aok. You show me a truck that will get 9mpg hauling bulk liquids at 80k lbs plus be reliable and I will give you 1000 dollars right after I buy that truck and get 50k miles on it while averaging 9mpg.
     
  4. dpfndefbad

    dpfndefbad Bobtail Member

    Messages:
    35
    Thanks Received:
    2
    Joined:
    Oct 31, 2012
    Location:
    PA
    Where was this 178f temp change recorded? Cylinder head temp? Coolant temp? Oil temp? Outside air temp?
    Exhaust gas temp? I need some clarification.
     
  5. durallymax

    durallymax Medium Load Member

    Messages:
    318
    Thanks Received:
    90
    Joined:
    Jan 30, 2011
    I'll start by saying your case sounds like component issues. That said, it seems you speak out of rage and clearly have troubles with comprehension. If you hate the system and lost the money trade the truck. A truck without it is much cheaper. There are plenty of people running these vehicles without issues. There is a lemon or basket full of lemons in every bunch. They are working a lot of bugs out of these things. They did rush them in a way because they all drug their feet somewhat hoping to not have to get to this point.

    I stated throughout my posts that I do not know enough about ALL commercial trucks to draw a conclusion about what each truck should do in every case. Same thing with off road. I don't know exactly what every OEM has their machine programmed to do. There is no exact standard. Same applies for on-road. I prefer to only speak when I have confidence and sufficient knowledge on the background of the statement, I don't like giving midleading information or coming across as someone who speaks out of rage versus knowledge.

    I do not work for any OEM. I am just a dumb farmer. We deal with these systems all day.

    Your statement about pulling over for a manual regen is exactly why I stated I don't know enough on commercial trucks. In other vehicles you only have to do a parked regen in extreme cases if ever. Many will pause the regen if you stop driving. To me it seems very odd that a parked regen would be the norm for a commercial truck. I think if every truck truely had to do this there would be a lot of pissed off people in the industry. If it is the extreme scenario, then its a different story. Thats what I am getting at with peoples claims too. Everybody will go out and Bash Volvo's off road system saying you have to do a parked regen. They take it completely out of context. You almost never have to do a parked regen. It is simply there in the extreme scenario.

    Your statement about burning fuel to reduce emissions also shows the old school ignorance to the issue. You do remember that the SCR and EGR are working to reduce NOX and the DPF is working to reduce PM. Burn all the fuel you want those two systems will still stop it. CO emissions are minimal on a diesel, CO2 are higher and yes you can have slightly higher CO2 emissions due to the emissions systems, however the PM and NOX are still nearly non-existant and that is the important part. Just because everything is converted to the CO2 footprint does not mean it is the central goal.

    I never say SCR is cleaner than DPF because the two do not replace each other. SCR/EGR/DPF engines are much cleaner burning than just EGR/DPF alone. I could care less about the overall carbon footprint that is not what I was talking about. I was talking about the carbon that gets into your oil, the frequency the DPF, VGT and EGR plug up from all of the soot. With SCR added to the engine, they are able to run cooler EGTs and hotten cylinder temps, thus preventing the creation of extra PM to begin with and thus being cleaner burning engines. Take the DPF off of an EGR/DPF truck, floor it, you will get a puff of black smoke from the low cylinder temps, retarded timing, and high EGR flow. Take the DPF off of an SCR/EGR/DPF truck and you will see how much cleaner that engine runs at an engine level. Once again to clarify when I state clean, I am talking in cylinder cleanliness. Not overall carbon footprint as you could argue that for days. We could go on and on about how wiping my ### every other day reduces my carbon footprint because of the logistics of the toiletpaper, but the reality of it is that my ####### would be dirtier than if I wiped it every day. While I do see your point, its not my point.

    As for DEF logistics and availability, dispensing systems are being put in more and more. The logistics and carbon footprint of these is very low. These systems use tanker loads, so no plastic and minimal handling. A local trucking company hauls from the port in Louisiana back up to the upper midwest and has no troubles finding plenty of DEF without needing to buy any 2.5 jugs. Its a new system. Give them time to get an infrastructure in place. Not like they could take on the task before the trucks hit the market because DEF has a short shelf life and its hard to invest that much capital with no profits.

    If you want to argue overall carbon footprint, the reduction in towing bills, overall fuel useage, DPF/EGR components and such, has drastically offset the footprint of the DEF dispensing and SCR component failures.

    Clearly you have a bad truck. Like everything, bad apples in every bunch.

    Are these trucks the bulletproof trucks from the glory years 80s-90s-early 2000s? Nope, never will claim they are. But for what they OEMs are working with these things are performing better every year. Its going to take awhile, but they will. Look at the issues when they started emissions controls on cars in the 70s, now look at them? Other than people leaving the gas cap off what other issues do they complain about?

    Could the OEMs have done a better job before pushing them to market? Yes but thats what happens. It takes a lot of years to prove a product and 10 years ago they were hoping they didnt need to do any of this.

    In my dumb farmer talk, if you dont like it get rid of it? Just like anything else in life. If you are the one loosing $10,000 you must own it therefore you have the power to sign the papers over. Being a new truck it should be worth a lot. Build yourself a glider, buy an old truck, get out of trucking, or learn to live with it for now. Some things you just accept and move on. Nobody actually likes these systems but we also know the emissions regs will not be undone, easier to just keep an optimistic outlook on it and work with the OEMs to help them improve the systems.

    I do not state the EPA makes them use DPF/EGR/SCR, although re-reading my post it may come off that way. The statement I made was referring to those who go off about how the EPA is bad for making these trucks have the added equipment. The EPA doesn't say how they have to do it, but SCR is currently the only way to do it. Why reinvent a proven technology thats been in use for 50 years.

    The OEM's chose SCR because it is currently the only way to do it. Look at Navistar. They sued the EPA over it, they didnt want SCR, they gave up and said it can't be done. Off-road engines all have gone to it as well.

    They could probably do it without it, but the engine wear, fuel useage and repairs would ruin their name and piss off you the customer. This is the most economical way for now. If you have a better way, please elaborate. While OEM's want their money, they also have a reputation and if others are beating them, they loose more money.

    Can't show you one getting 9, but can show you thousands of SCR equipped trucks doing over 1mpg better than their non-SCR counterparts all while having lower downtime and repair costs.

    Outside air temp is what I believe he was referring to. IE driving in 100* weather and -78* weather.
     
  6. Sportster2000

    Sportster2000 Road Train Member

    Messages:
    1,023
    Thanks Received:
    236
    Joined:
    Jan 5, 2008
    Location:
    Indiana
    I was getting 8.9 driving an areo truck with a 53 box trailer at 78,000 lbs.

    The temp change was ambient over the course of 6 months. The coldest I have driven/worked on a truck in is -48 F.

    SCR is not a cheap solution to the emissions regulations, but it is industry accepted solution.

    The amount of EGR that Navistar was going to have to flow through their engine to make it work was also going to make it a 200,000 miles engine.

    About the Cummins tech problem, I can't help you with that. It seems like they took the easy way out of the problem. I did hear that they were having problems with their nox sensors so you may have got a bad replacment.

    It seems that I was in a bad mood last night so I would like to apologize if I came across a little harsh last night.
     
  7. dpfndefbad

    dpfndefbad Bobtail Member

    Messages:
    35
    Thanks Received:
    2
    Joined:
    Oct 31, 2012
    Location:
    PA
     
  8. durallymax

    durallymax Medium Load Member

    Messages:
    318
    Thanks Received:
    90
    Joined:
    Jan 30, 2011
    well all agree we would rather not have it, just trying to show people it's really nother the big evil many make it out to be.

    Whenever I say the SCR engines are better , I am referring to the alternative option of just DPF/EGR not to an engine with no emissions equipment.


    Take any one of these new SCR engines though without the emissions equipment and good tuning and they would walk all over the older engines in terms of performance and economy. Considering how choked down these engines are its amazing were getting the same fuel economy better than non emission engines.
     
    DrtyDiesel Thanks this.
  9. dpfndefbad

    dpfndefbad Bobtail Member

    Messages:
    35
    Thanks Received:
    2
    Joined:
    Oct 31, 2012
    Location:
    PA
    You ever look at the intake on a 500 cummins with dpfbutno scr? Some genius engineer decided to put the air intake temp sensor 4 inches downstream of the egr induction pipe which causes it to get encased in soot and fail causing engine to derate. Nothing to do with dpf or scr just something over looked by an engineer. On my 12 they moved it 2 inches upstream so it only gets clean air and must of adjusted the ecm fuel map to average the temp of clean air and egt sensor. Not exactly what brings to mind America's best and brightest.
     
  10. durallymax

    durallymax Medium Load Member

    Messages:
    318
    Thanks Received:
    90
    Joined:
    Jan 30, 2011
    honestly I have no clue where you are going with this post or who/what it was directed at?

    EGR is an emissions component used to control NOX as well. It's part of the total package.

    So an engineer overlooked something or tried something and it didn't work. Maybe they were going for the higher temps after EGR. It happens a lot.

    I wouldn't classify American made very high on Any list but cheeseburgers maybe. When it comes to equipment, quality and innovation we are very far behind with a lazy workforce and too many regulations to produce quality products which is why European and Asian countries walk all over us. GM sold the most cars by volume last year and turned a profit of 7 billion. VAG sold the 3rd largest amount of cars by volme but produced more income than any other OEM at over 25 billion. Chevy runs deep in my blood and I like my duramaxes, but all of my families VAG products are far superior in fit, finish, styling and overall ingenuity and quality. Not to mention good value.

    Sent from my SCH-R530U using Tapatalk 2
     
    DrtyDiesel Thanks this.