Engine/Transmission (1994 - 1998) diesel hp rating for pounds per minute

[hereismylife]

How much hp do you get for 1 pound per minute of air flow on a diesel?



Some reason we get less on diesels vrs the gassers.



Anyone know



thanks



example: If a turbo flows 69 lbs per minute how much hp with fuel only at the rear wheels?



Trying to learn this..... Oo.

 

[cojhl2]

How much hp do you get for 1 pound per minute of air flow on a diesel?



Some reason we get less on diesels vrs the gassers.



Anyone know



thanks



example: If a turbo flows 69 lbs per minute how much hp with fuel only at the rear wheels?



Trying to learn this..... Oo.

I don't see where airflow has a relationship to HP. The airflow will be related to RPM and volmetric efficiency. HP will be related to diesel rate.

 

[hereismylife]

K what would a 69 lbs per minute turbo at 3000 rpm with 30 lbs of boost produce?

 

[SRadke]

Here again, fuel makes hp, not air. Your fueling rate will dictate your horsepower and within that fueling rate changes in airflow will change your exhaust temperature. Diesel engines will make power under a much wider stoichiometric ratio than gasoline engines. This allows substantially more variance in airflow at the same power level.

-Scott

 

[hereismylife]

K what would a 69 lbs per minute turbo at 3000 rpm with 30 lbs of boost produce with 75 ddp injectors no plate no afc mack/rack plug?

 

[Bob4x4]

K what would a 69 lbs per minute turbo at 3000 rpm with 30 lbs of boost produce with 75 ddp injectors no plate no afc mack/rack plug?

Too many variables... .....

 

[cojhl2]

Maybe you should be asking..

Maybe you should ask,(not a generic question) how much fuel to develop a given HP ,, then how do I get enough air (oxygen) to oxidize that amount of fuel.



I think maybe your original question comes from some SI engine measurement where the air/fuel (15/1) is fairly fixed. Since that ratio is fixed then maybe a relationship between air rate and HP is possible.



But NTL your question is unanswerable.

 

[hereismylife]

I get what you are saying guys. We are trying to figure the turbos out and what does what.



somehow they figure out how much a turbo will make.



Does someone know how to figure out why you can only make a little hp with fuel only with a certain turbo vrs what the cars do if you boost 60 psi...



the gassers only run 20-30 psi and make more power





Somehow when you tell guys oh this turbo..... they say it is good for this hp?



How do they know this... .....



oh I have a hx 50 oh that will give you XXX hp on fuel... . ect... ect

 

[Curious Dave]

Air does matter in the formula... So does stroke and bore... . The guys that give you these numbers are giving guestamations that they have acheived thru trial and error and also what they have seen others do. Waaayyyyy... . to many variables... . journal diameter, clearance, oil viscosity, % of air vs fuel, temp. of engine, temp. of air, cam specs, air flow of heads and intake, on and on.

 

[hereismylife]

Air does matter in the formula... So does stroke and bore... . The guys that give you these numbers are giving guestamations that they have acheived thru trial and error and also what they have seen others do. Waaayyyyy... . to many variables... . journal diameter, oil viscosity, % of air fuel, temp or engine, temp of air, cam specs, air flow of heads and intake, on and on.

Right I agree. thanks

 

[cojhl2]

Here again, fuel makes hp, not air. Your fueling rate will dictate your horsepower and within that fueling rate changes in airflow will change your exhaust temperature. Diesel engines will make power under a much wider stoichiometric ratio than gasoline engines. This allows substantially more variance in airflow at the same power level.



-Scott

Maybe this is a good place to get an answer to a question I've always had.



Why does a gasoline engine combustion get hotter when running lean? It seems that it should get cooler because there would be less fuel to burn. .

 

[Curious Dave]

cojhl2... . It is the same thing as having nitrous with no fuel... To much oxygen. Unless you retard the timing, or fix the lack of fuel it will be to hot and cause detonation. If it happens more severely then you have the failure of head gaskets, cracking heads, burning spark plugs, burning valves, pounding out the valve seats, burning the valves... . all sorts of fun stuff.

Don't try this!!!!

But... you can actually put a lit match out in a bucket of straight gasoline. No oxygen, or a lower % of oxygen that will not allow a proper mixture for combustion. As soon as you start adding oxygen the combustion gets hotter.

Oxy-Acetylene is the same way along with other torch configurations.

A really great fuel would be hydrogen... but it is rather flammable and unsafe.

Stoichiometry for gasoline is @ 14. 1:1... more than that and you are lean... less then that and you are rich. The timing plays a role in that as well. . but is more complicated. You can have the correct "S" ratio and have the wrong timing.

Check this out... . Lean Burn Combustion, 101.

Have fun.

 

[cojhl2]

cojhl2... . It is the same thing as having nitrous with no fuel... To much oxygen. Unless you retard the timing, or fix the lack of fuel it will be to hot and cause detonation. If it happens more severely then you have the failure of head gaskets, cracking heads, burning spark plugs, burning valves, pounding out the valve seats, burning the valves... . all sorts of fun stuff.
Don't try this!!!!
But... you can actually put a lit match out in a bucket of straight gasoline. No oxygen, or a lower % of oxygen that will not allow a proper mixture for combustion. As soon as you start adding oxygen the combustion gets hotter.
Oxy-Acetylene is the same way along with other torch configurations.
A really great fuel would be hydrogen... but it is rather flammable and unsafe.
Stoichiometry for gasoline is @ 14. 1:1... more than that and you are lean... less then that and you are rich. The timing plays a role in that as well. . but is more complicated. You can have the correct "S" ratio and have the wrong timing.
Check this out... . Lean Burn Combustion, 101.
Have fun.

Thanks Curious Dave, your analogy of the Acetylene torch is excellent.

I have as we speak a IH tractor where the intake manifold was leaking right next to # 2 and it just about destroyed the piston. In fact the cyl wall is scored at that point.

Thank you for taking time for such a complete response.

I just got back from reading that paper. It is excellent!!! It answered questions I've had for years. Years ago my friend and I build a fuel delivery system into a SI engine using only vapors from gasoline. I now understand how it worked while providing better efficiency than the normal carburetor.

 

[Curious Dave]

Glad to help.