Tractor Performance: diesel vs gas

[SPYDERLK]

When comparing equally matched horsepower ratings of engines diesels win in torque every time.
Example. HP=torque x rpm/5252. Torque=hp/(rpm/5252).
A 22hp gasser that gets peak hp at 3600 rpm has 32 ft/lbs of torque. A 22 hp diesel that is rated at 3200 rpm has 36 ft/lbs of torque. Yes, a very small differance but still a differance.

As the formula shows, slow rotating engines must produce more torque to achieve equal HP. There is no advantage to the slightly slower turning engine. The two just need different gear ratios to apply their hp effectively. The diesel advantage is that its torque curve is flatter. It has more tractable power delivery and demands less of the operator/transmission. It "wins" because it is easier to use.
larry

 

[Egon]

Can an engine burning other fuels be designed so the torque band is sorta the same as that of a diesel?

 

[LBrown59]

Are you buying farm fuel, bulk or? Our farm fuel has a higher sulfur content, mind you not much higher than road fuel.

What about the fuel down there?

I will be making sure conditioner is added before we put it in, and WILL NOT use road fuel unless an emergency.

Thank the tree huggers, and send them your repair bills too.

I doubt if there is much if any of the old fuel left that the refineries had on hand when they made the switch to ULSD.
There may be scattered pockets across the country where it's still available but I would say it's the exception rather than the rule.
After this long on ulsd the stock pile of the old stuff has probably dwindled to zero or nearly so.

We can only get one fuel here.

L . B .

 

[RobJ]

I doubt if there is much if any of the old fuel left that the refineries had on hand when they made the switch to ULSD.
There may be scattered pockets across the country where it's still available but I would say it's the exception rather than the rule.
After this long on ulsd the stock pile of the old stuff has probably dwindled to zero or nearly so.

We can only get one fuel here.

L . B .

If you are talking about just small tractor places them maybe. Our refinery continues to make HS diesel today. The law is 2012 but there are exemptions for smaller refinerys that will extend that. All of our diesel is dyed, we sell to marine and construction companies. Anything offroad.

If we never install a hydrotreater to remove the sulphur, we can still sell it to other refiners that will make it into other products or remove the sulphur. The refining unit to remove the sulphur is expensive. then you have to buy or make the hydrogen.

 

[WilliamBos]

If you are talking about just small tractor places them maybe. Our refinery continues to make HS diesel today. The law is 2012 but there are exemptions for smaller refinerys that will extend that. All of our diesel is dyed, we sell to marine and construction companies. Anything offroad.

If we never install a hydrotreater to remove the sulphur, we can still sell it to other refiners that will make it into other products or remove the sulphur. The refining unit to remove the sulphur is expensive. then you have to buy or make the hydrogen.

The High sulfur diesel is still way lower than the old diesel of years ago. Off road diesel and home heating oil is the same stuff.

 

[MossRoad]

Can an engine burning other fuels be designed so the torque band is sorta the same as that of a diesel?

Hmm... what fuel are you thinking?

 

[Egon]

Hmm... what fuel are you thinking?

natural gas, propane gasoline, alcohol.

 

[SPYDERLK]

Can an engine burning other fuels be designed so the torque band is sorta the same as that of a diesel?

I believe so. A place to start is a hard look at the Britten 1 liter V-1000 race bike. The engine has 14:1 compression and is tractable fom idle. It makes a steady 155HP thruout the 8000 to 13000rpm range. I believe the key is in making extremely high compression work with the fuel of choice.
larry

 

[john_bud]

Can an engine burning other fuels be designed so the torque band is sorta the same as that of a diesel?

Yes, the gasoline engine of tomorrow (3-7 years) will be using basically the same common rail fuel injection as todays diesels. 22,000 psi injection pressure. The engine will be run throttle open all the time and fuel injected in pulses so that a steady high pressure can be maintained during the down stroke. That will increase fuel economy by 20% to 30% and increase maximum torque by up to 50%. Best of both worlds in some ways. Now if they combine that with 6 stroke tech using water injection on the 5th stroke, waste heat can be converted to torque and higher economy.

jb

 

[hosejockey2002]

To answer the quote above, yes, a "gas" (spark plug) engine can be designed and tuned to deliver similar torque characteristics to a diesel. This John Deere CNG Bus Engine delivers 280 hp at 2200 RPM, which translates to a very diesel-like 668 ft./lbs. of torque at the same RPM.