DEF going away ?

[LouNY]

Bro, no need to keep being rude about this. I only typed all that out to try to help you understand the situation more fully.

Regarding your 80/20 notion, you are squarely in the minority of Americans, actually. The vast majority of us have no issues with reliability on our vehicles and prefer cleaner exhaust coming out of truck tailpipes. So keep yelling at the clouds if it makes you feel better, but it's a shame you aren't willing to to find any nuance or common ground in this. And in the engineering community who actually produce the products you depend upon, we actually also agree and must follow public policy and regulations regardless.

Like, so you are grumpy about some failing EGR valves and SCR sensors needing work occasionally. The rest of us don't care, thats the price of clean air. Pass the cost of downtime on to the consumers (as you already do) and we'll pay for it. It's worth it.

Don't lump me or any of the farmers or other truck enthusiasts that I know in with you. We despise the crap it fails frequently, it is expensive repairs and replacements with down time when down time can and will cost you $1000's of dollars.
In ag anything after tier 3 is an expensive nightmare.
When fuel efficiency decreases because of emission requirements, that is completely counter productive.
If you go to any forum concerning diesel engines including this one you will find very few people that are pleased with the garbage being foisted on us.

 

[Hay Dude]

Nothing will change an engineer’s outlook on things better than operating the crap they design for a 5-10 years while attempting to make a profit.

 

[Too many Kubotas]

If a diesel runs at max air all the time, how does it throttle down?

I suspect that it slows down by cutting the fuel. At least that's how my diesels seem to operate.

It's similar to that a carburetor supplies less gas when the throttle is closed and there's no meaningful airflow to draw the gas into the venturis.

Without the diesel's injectors supplying much fuel the engine runs at lower rpms and there's very little airflow through its wide open intake.

At least that's how I thought it works, but I'm always willing to learn.

 

[Snobdds]

I suspect that it slows down by cutting the fuel. At least that's how my diesels seem to operate.

It's similar to that a carburetor supplies less gas when the throttle is closed and there's no meaningful airflow to draw the gas into the venturis.

Without the diesel's injectors supplying much fuel the engine runs at lower rpms and there's very little airflow through its wide open intake.

At least that's how I thought it works, but I'm always willing to learn.

Put a piece ribbon in front of your air filter housing, with the filter removed.

Now see how much it sucks in at idle and how much it sucks in at full throttle. The only thing that changed is the fuel. At what position did the ribbon want to get sucked in more?

A throttle plate is a restriction to flow. There are other things that create a restriction to flow; turbo egr, etc. Hell a jake brake could act like a throttle plate.

However, i think most electronically controlled diesels today use a throttle plate of sorts.

 

[Too many Kubotas]

I am so behind the times. Of the 14 diesels I have, only one has a throttle plate, and also one of them has a Jake Brake.

Oh well, one of these decades I'll get an idea of how engines work.

Either way, it does seem that we agree on that a diesel's air flow is dictated by how fuel it gets.

EDIT: Sorry, forgot about two of them. One, a tier IV skid steer might have a throttle plate.

 

[Hay Dude]

Am I lacking sleep, or doesn’t the turbocharger force a variable amount of air into the diesel engine?
Like the more fuel, the more the turbo spools & builds pressure the more air/air pressure?
Turbos run like zero boost at idle and 35lbs boost when I’m in it on my smaller cummins. My International HT570 follows same pattern. So do all the farm tractors.
The amount of airflow would be quite different between idle and 2000RPM with a load on the motor.

 

[Too many Kubotas]

The amount of airflow would be quite different between idle and 2000RPM with a load on the motor.

Of course, but isn't that flow dictated by how much fuel the injectors are asked to deliver?

 

[rScotty]

I suspect that it slows down by cutting the fuel. At least that's how my diesels seem to operate.

It's similar to that a carburetor supplies less gas when the throttle is closed and there's no meaningful airflow to draw the gas into the venturis.

Without the diesel's injectors supplying much fuel the engine runs at lower rpms and there's very little airflow through its wide open intake.

At least that's how I thought it works, but I'm always willing to learn.

Accelration is all about what happens initially.

Gasoline and diesel engines work on opposite sides of the best burn curve....the "stochiometric curve" - and both engines will accelerate when the mixture approaches the peak of that curve.

The gas engine is always running on the rich (left) side of the curve below - between 0.5 and 1.0, so adding more air makes the mixture burn better and the engine picks up speed.
The diesel engine is always running a bit lean. It is over there on the right down toward 2.0 at idle, and so It already has plenty of air and wants additional fuel to make its mixture burn better. That's why adding more fuel makes the diesel pick up speed.

Here is a nifty graph adapted from a post by Rancher Ed some years ago.

rScotty

 

[Snobdds]

Accelration is all about what happens initially.

Gasoline and diesel engines work on opposite sides of the best burn curve....the "stochiometric curve" - and both engines will accelerate when the mixture approaches the peak of that curve.

The gas engine is always running on the rich (left) side of the curve below - between 0.5 and 1.0, so adding more air makes the mixture burn better and the engine picks up speed.
The diesel engine is always running a bit lean. It is over there on the right down toward 2.0 at idle, and so It already has plenty of air and wants additional fuel to make its mixture burn better. That's why adding more fuel makes the diesel pick up speed.

Here is a nifty graph adapted from a post by Rancher Ed some years ago.

rScotty
View attachment 4593183

I want you to conduct an experiment.

Go to your diesel engine and remove the air filter. Spray some diesel in using a water bottle. Does the engine automatically increase in RPM.

Report back.

 

[Too many Kubotas]

I want you to conduct an experiment.

Go to your diesel engine and remove the air filter. Spray some diesel in using a water bottle. Does the engine automatically increase in RPM.

Report back.

No need for that "experiment", really.

The same basic thing happens every time I spray ether into the intake tract, since I'm adding "fuel" through the wide open intake, in addition to what the injectors are supplying. No need to remove the air filter either.