2020 GMC Sierra HD

[ovrszd]

Diesel's have a lower RPM because the pistons have a longer stroke. The speed the piston travels is still equivalent to higher revving shorter stroke engines. The longer stroke increases the output torque by taking advantage of the combustion characteristics of diesel fuel.

Very well stated.

 

[zing]

Diesel's have a lower RPM because the pistons have a longer stroke. The speed the piston travels is still equivalent to higher revving shorter stroke engines. The longer stroke increases the output torque by taking advantage of the combustion characteristics of diesel fuel.

Yes, this. When you say "the combustion characteristics of diesel fuel" I am guessing what you mean is that diesel is a slower burn that provides expansion gases through a longer portion of the stroke. It is like comparing a smaller number of long pushes, to a higher number of fast pokes. Quickly poking something light can get it moving fast, but the long push does a better job of getting a heavy weight up a hill at a steady speed.

 

[buickanddeere]

Actually Torque does work, HP is just a theoretical figure on how fast the work can be done. Torque is measured, HP is calculated.

Put your high torque 200HP engine on a generator and a moderate torque higher rpm 300HP engine on a generator . Tell us which can carry a higher Kw load ?

 

[TMGT]

Put your high torque 200HP engine on a generator and a moderate torque higher rpm 300HP engine on a generator . Tell us which can carry a higher Kw load ?

Why not tell us and the reason why?

 

[buickanddeere]

Diesel's have a lower RPM because the pistons have a longer stroke. The speed the piston travels is still equivalent to higher revving shorter stroke engines. The longer stroke increases the output torque by taking advantage of the combustion characteristics of diesel fuel.

Long strokes small bore designs ç*¥nder square are used on diesels as it is easier to obtain a high compression ratio . Short stroke , large bore designs are used for lower compression and higher rpm applications .
The larger bore also allows larger valves for improved high rpm airflow .
Per cubic inch displacement and same compression ratio . Under square and over square engines make the same power .
The larger surface area of the piston makes up for the reduced leverage of a shorter stroke .

 

[4570Man]

Put your high torque 200HP engine on a generator and a moderate torque higher rpm 300HP engine on a generator . Tell us which can carry a higher Kw load ?

You mean before they melt? Cars and light trucks aren’t a continuous duty hp rating. And unless you have a gear box to get the high rpm motor in the power band the 200 hp motor will win.

 

[buickanddeere]

Why not tell us and the reason why?

If you do not understand now , pages of further explaination will not make any difference . Could also be you are just playing games and don’t want to know .

 

[buickanddeere]

You mean before they melt? Cars and light trucks aren’t a continuous duty hp rating. And unless you have a gear box to get the high rpm motor in the power band the 200 hp motor will win.

Serious or just pulling my leg ?
Do you know any high school physics teachers ? Show them the statement .
Melt ?

 

[TMGT]

If you do not understand now , pages of further explaination will not make any difference . Could also be you are just playing games and don’t want to know .

How am I playing games? You make a claim, I asked you to substantiate it. It's not my responsibility to provide the support for your claims.

I've spent a lot of time working on engine designs and operating dyno's, if you dont agree with what I stated about torque/hp that's fine but nothing I said was false, go ahead and research it. And no I'm not here to get into a pissing match about it.

Since you like examples I can point you to a old 4cyl 2stroke diesel that operated a generator that powered a town, I'd have to find the electrical specs but the engine output was 300hp @ 300rpm giving it a torque output of 5,252ftlbs. Pretty sure the electrical output is higher then a 350hp 5-600ftlb genset.

As for engine designs, we could go all day about bore/stroke/piston speed/piston acceleration/VE/flame propagation etc. but I dont think this is the right thread to go down that path.
Plus typing all this on the phone isnt easy.

 

[4570Man]

Serious or just pulling my leg ?
Do you know any high school physics teachers ? Show them the statement .
Melt ?

Serious. How long do you think a car or light truck engine will run under continuous load at rated hp? I’m betting not very long and I’m betting overheating is the first point of failure. What does the high school physics teacher have to do with it?