Tier 4

[Snowback]

Oh boy, this may get me in trouble but here goes. It may prove to be better to have the DPF/SCR than the "work around" The "work around" is expensive to repair. Once you have it there is no way that I am aware of to get rid of it. The DPF/SCR that you might be able to get rid of. So, those of you that have or are going to make a decision.... stop over thinking it?.... Me I gave up kept my old stuff, not sure how wise that was, prone to failures and the "work around" is all that is left. Newer used costs a fortune. So, waiting is not such a god idea, tier v is out there, yes you heard correct.
Beyond Tier 4 Engine... | New Tractors | Agriculture

Tier 5 - Yikes! Thanks for the input truckdiagnostics. I largely agree with you, and should have communicated better. The new mCRD Mahindra engines are by no means work arounds in my opinion - but I did word it that way, so my bad. Please accept my apologies. I think Mahindra has taken the next step already. The engines provide a better and more efficient combustion process that helps eliminate the need for an add on filter and regen. The common rail injection system uses higher pressures, and the direct oxidation catalyst process helps scrub the end exhaust product to get fumes in check. Also - these new engines are of a wet sleeve design and should be less costly to rebuild or repair for those who put loads of hours on them. I think the DPFs are fine, and even a system using fluid like in trucks could be tolerated. It's just my personal preference not to have that filter burning like the sun every few hours, and since a lot of my use is short term type work I might get stuck having to run another 20-30 minutes if the regen kicked in as I was ready to call it a day. At the least I would encourage folks to check out the Mahindra mCRD technology even if they go with a different color that uses DPF. For now we won't talk about those guys that used to cut the cats off their cars and trucks back in the day. And I certainly wouldn't be talking about myself... no way...

This raises the question of whether a guy could potentially bypass the DPF/SCR found in some tractors in case of an "emergency" so as to get the tractor into the shop, or perhaps around the pasture a few thousand times...???

AxleHub - I think the smaller Mahindras (26HP and below) are still getting away without using a DPF and are not mCRD as the emissions requirements are not yet as stringent for the smaller HP engines, and they simply don't put out as much exhaust as the bigger units. I think this is why the Max 28 was dropped to a Max 26XL. Please double check that with a Mahindra dealer, but I do believe I remember hearing that a few weeks ago. (Would be the same for other brands as well I assume). I didn't pivot off it as my Max 25 is Tier 3 with no extra jewelry and this go around we were looking for a 35-40 HP unit.

At the end of the day the requirements and technologies will both continue to increase. I remember being able to completely rebuild an early 80's Chevy 350 engine in auto shop class during High School, but I can't imagine that is even remotely possible these days. A guy needs to go UTI and essentially get a college degree just to change the oil in some of these new road vehicles. Tractors are not far behind.

I'll leave everyone with this Kubota dealer explanation to help everyone understand DPF a little bit better. It helps illustrate why I went with a 38 HP mCRD Mahindra as opposed to a 35-40 HP competing unit that required a DPF. It gets good at about the 1 minute mark.

https://www.youtube.com/watch?v=j9Ya1mp4cO0

I simply did not want a 1000 deg F fire burning in a filter POD under my hood every few hours, and I did not desire to run at high RPM all the time just to keep the thing from plugging up even sooner than needed. To each his own though... I respect that the technology works and honestly feel that it is not a deal breaker to have it. Rather the mCRD was a deal maker for me. Perhaps this new mCRD engine design will already be set up to address Tier V if/when that takes effect.

Take care everyone!

 

[jaydee325]

At peak efficiency, the DOC needs to operate at upwards of 300 deg C or 572 deg F. Reference

The DOC will also require cleaning at some point. Several services are already advertising this service.

Since the DOC requires "light off" to work, I'm not sure operating a low loads/RPMs for short periods of time will be any less detrimental on a DOC as an DPF.

 

[truckdiagnostics]

Going to go out on a limb again. I think you are going to see gas engines offered in your light/utility tractors. The hobby farm/residential owners are going to have a hard time justifying the increase in purchase and maintenance costs for diesel. Cummins did not jump into bed with westport for grins. Cummins Westport - About Us Yes, Cummins has gas engines in there product line. A Cummins Gasoline Engine? - Diesel Progress - July 2014 So, Cummins has had a good relationship with New Holland. My prediction is you will see gas fired engines in New Holland tractors sooner than latter. Maybe some other tractor manufacturer first, but it just makes sense.
Steve

 

[Snowback]

At peak efficiency, the DOC needs to operate at upwards of 300 deg C or 572 deg F. Reference

The DOC will also require cleaning at some point. Several services are already advertising this service.

Since the DOC requires "light off" to work, I'm not sure operating a low loads/RPMs for short periods of time will be any less detrimental on a DOC as an DPF.

Great info jaydee325 - Will need to do some more research on your points. Thanks for sharing. I think anything over a few seconds and your diesel exhaust is smoking hot - pun intended. I had to refresh my chemistry facts to confirm that diesel burns at 1,000 deg F+ (hence the need to inject/burn it directly in the DPF to clear the soot). Although temperatures drop quickly along the exhaust system of a non DPF machine, the working temperatures inside DOCs will typically not drop below the kickoff temperature of +/- 400 deg F and the catalyzation process works well most of the time, even at idle. I assume manufacturers get their passing emissions grade at the highest operating temperature, but engine performance is not hampered if the engine is not run hard and hot all the time. Even if the catalysation is not triggered or at peak efficiency, then the noxious gasses and soot typically pass through the device unlike in a filter where particles are trapped. Vehicular Cats can get clogged from contaminants or abusive low temperature fuel releasing events into the exhaust system, but those are rare. Grandma's car running to the corner store and back will often have a corroded exhaust due to this phenomenon as one of the byproducts of the Cat process is water. I will rarely be in a detrimental situation unless pulling in and out of the shed and stopping/starting the engine repeatedly. I wouldn't suggest that to anyone with any engine.

Another possible concern with DPF systems has to deal with the exhaust gas temperatures even past the DPF and at the exhaust tip while the unit is undergoing a regen. Since many CUTs drop their exhaust down towards the side and bottom of the tractor one should at least be aware of fire dangers. The Forest Service Fire Management Department even studied this on trucks and found this interesting data:

http://www.fs.fed.us/eng/pubs/pdf/08511816.pdf

Page seven of the PDF, (page one of the actual study), shows that it can be risky to park in dry hay when your regen is going. Or, an even better takeaway from this is that if you have a DPF please check for mouse or rat's nests nestled up to your filter can before heading out into the field or woods! :fire:

Be safe all! (And thanks for this great back and forth guys - I think we are all learning here - at least I am - and I appreciate you for it!)

 

[MHarryE]

How certain are you of your facts regarding the extreme temperature needed for a DPF to regenerate? My DPF equipped tractor has a DPF temperature that I watch out of curiosity. In much of my work, high PTO load or tillage, my exhaust temperature will be running over 1,000 degrees and the highest temperature I have seen at the end of a regen (that's when the temperature is highest) is 1122. Also I care an I-R thermometer with each of my large pieces of equipment with which I can check bearing temperatures on our balers, combine, etc., to detect an impending failure and avoid downtime during the day. I have checked my exhaust stack and don't not find it significantly hotter at regen than it is when normally working hard.

Does Mahindra have a design advanced above everybody else? I don't believe so because the technologies they advertise are ones we talked about in 2004 when the latest emissions standards were set. It wasn't a case of the major industrial countries saying here is a standard, now meet it. There was a lot to f work done between the countries and the engine manufacturers to determine what technology was possible and when before setting standards. And engine companies use multiple emissions systems on an engine size depending on how the engine is to be used. John Deere has a detailed explanation as to why they got where they are with a combination of nearly everything.

Until engines started changing with emissions regulations, most were running with ancient, not very efficient technology. When Tier 3 came into being and John Deere tested their first Tier 3 tractors with their first use of cooled can EGR, they blew away all past economy records with their 8000 series tractors. The technology has been there but nobody wanted to be first as there were bound to be teething pains and technology drives initial cost.

We at Caterpillar advertise our small wheel loaders as being 30% more fuel efficient than their predecessors. Of course that isn't the big advertising coup it would have been back in 2008 when diesel was $4.50 per gallon but back then who predicted there would be the oil glut we have today?

 

[5030]

While all your Tier 4 huggers smell your deodorized exhaust and wipe your exhaust pipes with a clean rag, I'll keep on blowing smoke and stinking. I like the smell of a cold diesel starting up and I like to see some black smoke when my tractors are working..... Have fun with your emissions crap, I'll pass thank you.

 

[GManBart]

So, Cummins has had a good relationship with New Holland. My prediction is you will see gas fired engines in New Holland tractors sooner than latter. Maybe some other tractor manufacturer first, but it just makes sense.
Steve

When was the last time New Holland made their own SCUT/CUT tractors? I'm not so sure we're going to see a Shibaura with a Cummins gas engine any time soon.

 

[Snowback]

Thanks for your input MHarryE. Empirical data is the best data. We just need lots of it!

How certain are you of your facts regarding the extreme temperature needed for a DPF to regenerate?

Pressurized diesel burns at about 1,000+ degrees in the combustion chamber. When diesel is injected and burned in the DP filter it serves as a secondary combustion chamber, so I am quite certain of that high temperature of regen. Most dealers and internet resources will tell you between 900 and 1,150+/- deg F inside the DPF during regen. I have not seen it in person, but believe the experts.

My DPF equipped tractor has a DPF temperature that I watch out of curiosity. In much of my work, high PTO load or tillage, my exhaust temperature will be running over 1,000 degrees and the highest temperature I have seen at the end of a regen (that's when the temperature is highest) is 1122. Also I care an I-R thermometer with each of my large pieces of equipment with which I can check bearing temperatures on our balers, combine, etc., to detect an impending failure and avoid downtime during the day. I have checked my exhaust stack and don't not find it significantly hotter at regen than it is when normally working hard.

Well this is good info. For you it is hot either way, which makes sense when working hard. I am curious if the high heat is on your manifold/DPF, or at the exhaust tip? Most diesel trucks will drop a couple hundred degrees across the turbo, but during regen they still have exhaust pipe temps 100-300 degrees higher than equivalent engines that are not going through an additional combustion process downstream of the engine block. My earlier observation about the higher exhaust pipe exit temps were directly attributable to the Forestry Service study I linked, and those were diesel trucks, not tractors - so a study should be done on tractors as well. I acknowledge that.

Does Mahindra have a design advanced above everybody else?

Yes - It appears so as far as what is commercially available. Please see Introducing our Tier IV "mCRD Technology" | Mahindra From a consumer and user standpoint, their design is simpler and easier to use in my humble opinion. I have a brand new 38 HP tractor and I do not have to think about DPFs or DPF regeneration. That is kind of nice, and and advantage to me, but maybe not to everyone.

Until engines started changing with emissions regulations, most were running with ancient, not very efficient technology. When Tier 3 came into being and John Deere tested their first Tier 3 tractors with their first use of cooled can EGR, they blew away all past economy records with their 8000 series tractors. The technology has been there but nobody wanted to be first as there were bound to be teething pains and technology drives initial cost.

Exactly - Mahindra stepped out and spent the money to make this happen without the need for a DPF. I hope there are no unforeseen teething pains that have not already been addressed...

We at Caterpillar advertise our small wheel loaders as being 30% more fuel efficient than their predecessors. Of course that isn't the big advertising coup it would have been back in 2008 when diesel was $4.50 per gallon but back then who predicted there would be the oil glut we have today?

Improved efficiency is great and we need to continue to improve. Kudos to you all at Caterpillar for the great work. I'm enjoying cheap gasoline and diesel right now like everyone else, but this likely won't last forever. The world consumes north of 93 Million barrels of liquid hydrocarbon every day. Most of that is crude oil with some NGLs and condensate thrown in. Sure we are producing just a bit more than that each day, but with the price of oil crashing there have been many rigs idled, and numerous mega projects put on hold. At a global consumption rate of almost 3 Billion barrels of oil per month, plus the laws of physics keeping a base production decline rate of 4% + in play, it won't take long to get the market balanced again. Fill up your tanks while you can!

 

[MHarryE]

The Mahindra article cited talks about what I consider "old tech." High pressure common rail injection with multiple injection pulses - at least 15 years since introduced on-highway, possibly 2008, maybe sooner, off -highway. I still have proto injectors sitting on my "memory shelf" from 2005 testing. Their SCR - introduced by several AGCO divisions in the mid-2000's. It doesn't really cite anything groundbreaking - it downgrades the competitors who have chosen to use DPF. Is lot of development by other companies has resulted from producing all combinations and putting test units in customer's hands. Like for my small segment I had 7 prototypes for our own and limited customer evaluation plus 35 units in the customers hands for 2 years - that was Tier 3 - I retired during Tier 4 development. High pressure common rail multiple shots per sequence - I still have injectors on my "memory shelf" from 2006. SCR - that was Tier 4. DPF - our Tier 4s did have that or we would have transient response problems with our unique cycle but passive regeneration the operator never know about and filter cleaning every 7,000 hours dealer set price at $200. The first 22 years of my engineering career involved combines where we left our exhaust behind us, well behind us. With Cat I was where to send the exhaust so you don't kill the crew, a requirement from our customers.

 

[TMR]

MHarryE...curious if you have followed the Kubota B 3350 Tier IV "issues"? Seems like Kubota had/has a problem with regeneration during cold weather?

Some posters seem to think the problem is pretty well figured out...essentially solved??

Considering a B 2650/B 3350 this spring and would like the extra HP for PTO...brush hog and box blade trail work...maybe a bit for pushing over small dead stumps with the FEL. A little reluctant to go Tier IV due partly to my tractor inexperience and what would likely be sporadic hours of usage. No current winter plans for the tractor.

BTW...I see you are north of me as the crow lies...I am five miles inland from Lake Superior about half way between Duluth and Two Harbors. Also have a 5th generation cabin in Brimson off Highway #44. 40 extra acres in Brimson and 80 acres at my home north of Lake Superior.

I had a chance to visit CAT factory in Peoria 3-4 years ago...1 million sq ft under roof...amazing. The automation was a thrill to observe. The size of the product was spectacular...HUGE wheel loaders among others.

CAT was investing in a client of mine a couple of years ago.

Any thoughts on 30+HP Tier IV...particularly B 3350...Thanks...TMR