Diesel newbie-operating questions

[Tx Jim]

There’s no throttle plate in a diesel, so it takes in the same amount of air per revolution at idle that it does revving or working hard. The compression cycle creates heat, but I believe it’s the fuel, when working, that will warm the engine faster than just pumping cold air through the motor with an idle amount of fuel being burnt.

I agree that there's no throttle plate in a diesel engine BUT I'd like to see some proof that a diesel engine ingests same amount of air at idle speed as full rpm's. May I ask what you think the purpose of a turbo-charger is? Please explain your theory of how fuel warms an engine without the aid of heat of combustion?

 

[IndyJay]

I agree that there's no throttle plate in a diesel engine BUT I'd like to see some proof that a diesel engine ingests same amount of air at idle speed as full rpm's. May I ask what you think the purpose of a turbo-charger is? Please explain your theory of how fuel warms an engine without the aid of heat of combustion?

Per stroke, not total consumption.

 

[Egon]

Turbo’s pressurize the inlet air forcing more into the cylinder on each suction stroke.

just compressing air will generate heat. That’s why intercoolers are used to cool the compressed air so it’s denser.

On a piston air compressor note that the head gets hot.

 

[Beeenvenue]

I agree that there's no throttle plate in a diesel engine BUT I'd like to see some proof that a diesel engine ingests same amount of air at idle speed as full rpm's. May I ask what you think the purpose of a turbo-charger is? Please explain your theory of how fuel warms an engine without the aid of heat of combustion?

He said same amount per revolution. Higher rpm - higher airflow.

 

[ROUSTABOUT]

You can shut the engine off and start it up to save a dollar worth of fuel. You can also buy a 300.00 starter which is way more than the fuel you save. My neighbor cranks his truck each morning early. Leaves it running all day until he comes in at 7:30 pm. Keeps them 500k miles. If he goes in the office it's out there idling. If he's on a location (oilfield) truck is idling all day six days week.

 

[Williy]

A truck is different than a tractor! Tractors are not
made to idle and the tier 4's you don't want to idle
them at ALL! I run my tractor at 1500 rpm's set
brake put in neutral and get off tractor and do what
I have to do then back in cab and back to work! IMHO
I don't believe its good to shut off tractor hop off for a
few minutes and then start back up believe its better
to keep tractor running keeping engine hot believe its
much better this way.

willy

 

[CobyRupert]

I agree that there's no throttle plate in a diesel engine BUT I'd like to see some proof that a diesel engine ingests same amount of air at idle speed as full rpm's. May I ask what you think the purpose of a turbo-charger is? Please explain your theory of how fuel warms an engine without the aid of heat of combustion?

Yeah, for her sake of simplicity I didn’t get into turbos, or friction losses in the intake and exhaust that are a function of rpm.

There’s the heat of combustion and the heat of the (air) compression. I believe that the combustion heat (by dumping fuel in and working motor at an rpm above idle) warms the motor quicker.

 

[SmallChange]

and the tier 4's you don't want to idle
them at ALL!

Can you please say more about this? I've heard similar things but never understood why. I have a pretty new tier 4 with about 60 hours on it, and still haven't gone through a re-gen cycle. It works hard some times, but usually it has a light load. And I'm also unclear whether by "idle" most people are referring generally to running the engine without a load, or more specifically doing that at low rpm. I think I've heard people use the word both ways.

 

[CobyRupert]

I think with Tier IV, what they really mean is that a low exhaust temp will clog the filter faster. An idle exhaust temp is probably lower than a faster (non-loaded) rpm, which is a lower temp than working it hard, etc..etc..
Even without Tier IV, my understanding is a low exhaust temp can cause wet stacking.

 

[Williy]

I want to keep the exhaust hot so I don't need
to regen any time soon so running/standing I
keep 1500 rpm's

willy