Tier 4 and beyond?

Nitric Oxide (or Nitrogen Oxide) is not Nitrous Oxide though. I guess that is where you had me mixed up.

ih100 said:

As John said. I didn't say N2O was carcinogenic, just the nitrous oxides. Mind you, if was, it wouldn't stop some of our dentists using it. As for the cars, everything in Europe burning petrol (gas) is fitted with a catalytic converter now. What extras do you have fitted in the states? Higher combustion temperatures cause formation of nitrous oxides, which aren't captured by the particulate filter. hence DEF injection.

Click to expand...

What really chaps my cheeks is the estimated volume of the emission the EPA is trying to control:

http://epa.gov/climatechange/ghgemissions/gases/n2o.html

A grandiose 5% of total emission and we the end user of machines have to field all these machine mods/inconveniences.

Sorry for the Confusion. I hear one major company has an engine running at ultra-high injection pressures to clean up all the hydrocarbons and particulates. Theory is it will only need def dosing as after treatment, no scr or filtration. Whether we'll see it in production or not, I don't know.

Was talking with a guy that has oil tank trucks and they are so disgusted with t4 the non ending problems.They have started buying glider trucks(new with no engine or Trans)and then buy rebuilt cat or cuummins non emission engines and install on their own!these trucks run slow in cold weather where these filter systems do not work. Seems like we are hardly moving ahead if this needs to be done!

Now Carb is throwing rocks at new technology. They appear to have a big problem in methodology of their study.

www.forconstructionpros.com/news/11248461/study-confirms-hybrid-earthmovers-fuel-economy-questions-exhaust-savings

Not sure how this applies to Dozers specifically but Bobcat is now introducing its new Tier4 engines (produced by Doosan) which do not use DPFs to meet emissions requirements. Very interesting, here is a little from their website...

"Bobcat Engines have a specially designed combustion chamber that minimizes the amount of Particulate Matter (PM) the engine creates. The amounts are low enough that a Diesel Particulate Filter (DPF) isn’t needed for Tier 4 compliance. This “non-DPF” solution induces simplicity because most DPFs require interaction and maintenance from the operator to keep the engine operating properly."

They use High Pressure common rail, ERG, diesel oxidation catalyst and Selective catalytic reduction. :drinkup

Not all small diesel engines require the DPF. The DOC and SCR would still take up the room of the DPF.

Any other initials we can add to this alphabet soup?

the DOC and SCR may take up the same space physically but I think its a better alternative as there is no operator input needed to keep the system up and running, also no need to add DEF fluid.

The smaller diesels I have experience with don't require the operator to do anything other than run the machine and not let it idle for extended periods of time. That is the same thing required of a system without the DPF.

The smaller engines will run lean and hot, so they're burning up the PM and just have to clean up the NOX

SCR with no DEF?

You sure about that?