40 series compared to 60 series and Tier4

[RickB]

The majority of Tier IV Final Diesel engines above 75 hp use DOF and SCR.

 

[Paystar]

Yes, there's a lot of confusion. As I read Eddie's original question, he wanted to know if every 60 series Kubota had the Tier4 emissions equipment - which is DPF (Diesel Particle Filter) and a computer to control the emissions & injectors. As far as I know they all do have those things. And nobody has said any different.

He also asked if the 40 series made from 2007 to 2012 was Tier3. Well, it was and it wasn't.
What the 40 series was, was Interim Tier4....which is sort of halfway between Tier3 and Tier4. And it got that way using old fashioned EGR technology which met the specs for NO (Oxides of Nitrogen) but also made those Interim Tier4 engines smoke a lot and burn a lot of fuel.
But at least they didn't have DPF & computers.

Frankly I think Eddie wants what a lot of people say they want - a simple old fashioned diesel with lots of gears and no fancy anything. Something they can wrench on & already understand.
For Kubotas, that would be the 30 series or early 40 series. Good luck finding a low hour one.

Paystar, yours is the first comment I've ever heard about excessive under hood heat. Where did you hear that? Reliable source?
EGR should be cooler than DPF. Not that it matters, since I doubt that anyone offers an stand alone EGR type emissions control on a new tractor anymore. EGR alone can't possibly meet today's Tier4 specs.

Big diesels are now coming with DPF & DEF both. Mercedes has that. Very clean burning and high efficiency. Two systems and two computers, but no problems. So it can be done.
rScotty

I forget where rScotty......but it was right from Kubota. And as far as that heat, I can't say with these small compact tractor engines if there is much of a difference but (I know, a whole different animal) on big class 8 truck engines, when International tried to go mass EGR they had all kinds of heat related issues with underhood components compared to an SCR engine with DPF and DEF.

While the DPF gets hot and needs to retain heat, the actual motor runs cooler.

 

[rScotty]

I forget where rScotty......but it was right from Kubota. And as far as that heat, I can't say with these small compact tractor engines if there is much of a difference but (I know, a whole different animal) on big class 8 truck engines, when International tried to go mass EGR they had all kinds of heat related issues with underhood components compared to an SCR engine with DPF and DEF.

While the DPF gets hot and needs to retain heat, the actual motor runs cooler.

OK, I understand now. The basic engineering problem with EGR and heat is that the EGR feeds part of the exhaust gases right back into the intake manifold to be reburnt. But those exhaust gases are really hot. Without some cooling they are way too hot to just dump into the combustion chamber..... big heat problems doing that..

So EGR systems run the entire exhaust through a heat exchanger in line with the muffler and that heat exchanger uses engine coolant to reduce the temperature of the exhaust gases so they can feed the cooler gasses back into the combustion cycle.
But all that extra cooling costs HP which also creates heat. Now they need a bigger radiator with more fluid, and a bigger fan that sucks HP spinning a larger coolant pump so more wasted HP. And if any of this isn't working right, the engine gets too hot. Or if the heat exchanger clogs with carbon (and they do) then things get too hot.

I think that is what your source was saying. Thanks for giving me a chance to think it through.
rScotty

 

[Paystar]

From what I remember reading from Kubota was that their biggest concerns was with the mini-ex's and skid steers where the engines are packed in a real tight space. They didn't want the extra heat in those applications.

It was also interesting to read in a history of Kubota article, it said Kubota was the very first diesel engine to go EGR and be certified when all this emission reductions started.

 

[rScotty]

From what I remember reading from Kubota was that their biggest concerns was with the mini-ex's and skid steers where the engines are packed in a real tight space. They didn't want the extra heat in those applications.

It was also interesting to read in a history of Kubota article, it said Kubota was the very first diesel engine to go EGR and be certified when all this emission reductions started.

Fifty years ago we would be more likely to know who brought out EGR for diesels. Back then, interest and knowledge about manufacturing and the way mechanical things worked was a part of the popular culture.

That has changed. Now popular subjects are discussions of financing, advertised specs, and how something is used more than how it works.

Not much discussion on technical subjects, though. I wonder why?

rScotty