(800) 853-2651
SHOP NOW

HP???

A

Anonymous-0

Well-known Member
Not that it's the hardest thing in the world to do, but a guy just confused the....out of me today.

We were talking about tractors and vehicles in general and he said that a vehicle with a diesel motor could outperform (pulling) a vehicle with a gas motor and more HP.
Then, we were talking about my tractor (26HP 3cyl 1.8L diesel) and he said that the same series tractor in 30 HP (4 cyl 2.2L) would take care of whatever I need. He said that it wasn't so much the 4HP as it was the extra cylinder and CC.

I'm either more thick headed than I thought or he's FOS.

Dave
 
Ummmmmm, sorta...

In VERY GENERAL and simplified terms, for a given
displacement a diesel will produce more torque
than a gasser.

Foot-pounds of torque is a much more reliable
indicator of work performed than claimed
horsepower.

I [i:654c4848f0]think[/i:654c4848f0] a diesel will produce more torque
at a given HP rating than a gasser, but I could be
wrong/confused about that.
 

My Kia sportage has 90 HP gas motor and his VW van/pickup has a 55hp diesel. Both 5sp trans and both cruise about the same (85-100 mph) but his diesel pulls the same trailer with less stress than mine.
What really confuses me is riding mowers and compacts with 20+hp gas motors and my 26HP tractor will handle much more.


Dave
 
Torque and torque rise(lugging power) has to be a factor. Number of cylinders doesn't make much difference. Look how many semi-trucks run 6 cylinder engines compared to V-8's. In your example, 4 extra HP might be all you need but just because the one engine has an extra cylinder makes no difference. You could even have the 4 cylinder in the lower HP tractor and the 3 cylinder with more HP. More HP and/or torque makes the difference, not number of cylinders. You can usually get more HP out of bigger displacement but then you can run into reliabilty problems. A turbo can squeeze the same or more power out of a smaller, lighter engine and still provide good reliability. Dave
 

Horse Power = RPM x Torque ÷ 10,000 Foot Lb.

Yes, I can see were the diesel, which could derive its horse power through Torque, could out pull a gas engine that derives its horse power through RPMs. Just my two cents. CC could be translated in some cases as Torque.
 
HP is HP. Torque rise vs. "power" baffles too many
people.
I wonder how the education system is graduating
students without the basics?
 
A diesel makes it's maximum torque at a low RPM. A gas engine makes its torque at a high RPM. That's why a semi can idle along in low gear with a heavy load behind it. I'd like to see someone put a souped up 400 HP gas engine in a semi and try to do the same thing. Dave
 
both could be right actually! torque does the work,all work, no torque or not enough torgue and no work done.
hp is a measure of speed, more hp faster work gets done,less hp slower work gets done.
but,,if I had a 100 hp tractor ,i could probably assume it would do more work than a 10 hp tractor up to a point
consider this,I have a lawn mower,its a typical 25 hp kohler engiine.my N has 23 hp, which would make more sense to plow with? the N of course would plow more simply because of the tourqe created .
SO its quite possible a deisel engine would out pull a engine with more hp,and its also possible a gas engine with more hp could out pull a deisel engine! the difference would be the one with more torque always will out pull the other,but on the flip side the engine with more hp will most all other things the same will pull FASTER than the other !LOL
just think of it this way, torque=work done, hp= speed work is done. comparing two different tractors to assess amount of work they would do would you to know more than just the hp of engine. a hundred hp tractor, would be slower naturally than a hundred hp car,even if they had the same engine,simply because its geared down to create more torque to pull more.simple huh?
 
90 hp Kia and 55 hp Diesel VW? At what rpm are ratings taken, what rpm for peak torque, what rpm is 80kph in 4rth gear, what rpm is 100kph in top gear? If diesel is rated at 5000 rpm and is 100khp in top gear 6000 rpm while your Kia is rated at 8000 to 9000 rpm but again 100 kph is maybe ??? 6000 and VW torque is fairly flat from 2500 rpm to 4500 and Kia is peak torque 6000 rpm with sharp drop above and below-- then towing in the 3000 to 5500 rpm range would be wher VW diesel is happy engine speed and Kia is just waking up speed. You comparing a pinzgaur to a trotter. RN
 
More liter displacement is equal to more torque produced. At least it sounds logical to me.
And of course you have to have the weight to make the torque do anything.
 
Hello Marto,
Here is a chart .
You cover the unknow value. You then multiply the 2 opposing values, and devide by the other value.
5252.1 is a constant used for the formula.
Guido
a30931.jpg
 
If you take two engines, with the same bore and stroke, the gas engine will make more horsepower and the same, or more torque at the same RPM.

The diesel always has less unless it's turbocharged.

Note I said with equal bore and stroke, NOT just the same total cubic inches.

The popular misconception about diesels being more "powerful" seems to come from these facts. . .

In the past, most diesels were built for heavy duty use - not for light cars and trucks. So, diesels tended to have longer strokes then gas engines in cars.

On the other hand, many industrial and farm-tractor engines WERE made in gas and diesel versions - with bore and stroke the same. It's easy to read the test specs. The gas engine always has more horsepower and at least equal torque at the same RPMs as the diesels.

Some companies if selling a tractor by a certain power level, just used a smaller gas engine then the diesel version - to make the same horsepower and torque (like a Deere 1020 with a 135 gas or 152 diesel). Same with the 1010, 2010, 2020, 4020, etc.

A few examples of engines with equal bore and stroke that came in gas and diesel:

Hercules made the GO130 and DD130 engines.
Case made the 188 in gas and diesel
John Deere made the 165 in gas and diesel.
Ford made the 172 in gas and diesel
Allis Chalmers 262 gas and diesel
Continental 157, 193, 260, 277, gas and diesel
International Harvester 144 gas and diesel
Massey Ferguson 206 gas and diesel
Minneapolis Moline 336 and 504 gas and diesel

Even a few car engines . .
Oldsmobile 350 gas and diesel
Isuzu 1.8 gas and diesel
 
Hello dave2,
Tourque = Force (F) x Lenght (L).
This meens that the longer the stroke the more potential for torque. The more torque an engine has, the more work it can do. Also the engine torque is multiplied by the final gear ratio to the wheels. There is a formula for that also.
There are many formulas to find the right gear ratio, torque, R.P.M for each application.
It all depends on how much work you need to do, at what speed and at what R.P.M.
It may sound complicated but it can all be done with formulas.
To find torque for an engine try the following formula:...........TORQUE = 5252 x HP / RPM.
Guido.
 
Yep, you dont see six cylinder gas engines in trucks like a IH Paystar 5000 its a 290 or whatever # cummins diesels, ect???
 
Hello Fawteen,
TORQUE is the turnig /twisting force of an engine. It is a measure of the engine capability to do work.
HORSE POWER is the speed at which the work is done.
Guido.
 
Hello dave2,
I'll bet you that the one that pulls the easyest has a lower gear ratio, and its running at an R.P.M that produces the most torque for the engine. G
Guido.
 
Geez, I have headache I"m no math major but I"ve run a Cummins 855ci PT 310hp Stieger Panther pulling a 10-18" on land hinge plow at around 3mph at times using a 10 speed tranny let"s see you do that with a 400hp Camaro.I"ve been asked the same question before and I had the deer in the headlights look :(LOL
 
Work or Power is a product of force over distance during a set period of time.

HP= torque X rpm /5252

Your lawn tractor to Cub comparison is comparing the chassis to chassis. Not engine to engine.
Put both the Kohler and N engines on a dyno and the results will be similar.
 
This is a great discussion. I have often wondered if they can get 35 HP out of the little outboard on my boat, why does a 35 HP tractor have to be so big (comparatively)?

The only thing that kinda made sense to me was thinking about the length of the stroke and the RPM and comparing it to using a wrench to turn a nut. A longer stroke is sorta like putting a cheater bar on a wrench. I'm not suddenly stronger, but the wrench is certainly easier to turn. If I hit the wrench with my hand rather than just pushing on it, a stuck bolt will sometimes move. Again, I'm not stronger, but the added energy of the higher speed makes it move (kinda like higher RPM). Don't know if that is entirely "correct", but I wasn't planning on plowing the lake bottom with my boat anyway.
 
You can make a lot of generalizations, but horsepower is horsepower. Two engines producing the same horsepower will do the same amount of work in the same amount of time IF you can keep both engines operating at rated power. But comparing the output of a light-duty automotive engine with a heavy-duty truck or tractor engine is apples and oranges:

The light-duty engine is designed to operate at rated power for only a brief period. The heavy-duty engine can operate at rated power indefinitely.

The heavy-duty engine probably has a much wider power band than the light-duty engine, which means it can operate close to rated power over a wider rpm range than the light-duty engine.

With regards to tractors, the ability to use the available power becomes an issue. A more powerful tractor of the same size and weight as a less powerful tractor may not be able to do any more useful work because it can't get the extra power to the ground.
 
Hello 135 fan,
Torque is what moves the load, Horse Power is the speed of the load.
There are/were applications of gas engines in tractors and straight trucks. They are not very good on fuel mileage but they get the job done.
Even Mack trucks had gas engines in them.

Guido.
 
If you changed the gearing to take advantage of the camaro engine's torque curve... then yes, it will do more work in an hour. The catch is that at 400 hp the 350 gas will not last all that long compared to the cummins. I'd suspect that the life would be measured in hours and days instead of years...
If you ran the camaro engine with the tractor's normal gearing for the Cummins engine... it wouldn't make but 1/3 of the advertized power because the engine would not be turning fast enough.

Rod
 
HP is a simple formula... IIRC it's something like this...

HP = [torque(ft/lb)x speed (rpm)]/5151

Bottom line is that you can increase power in two ways. Either make more torque or turn the engine faster with the same amount of torque. Lots of little engines turn at 7, 8, 10,000 rpm as opposed to 2000 rpm in a medium/heavy diesel. That speed makes for a lot of power even with a small amount of torque.

Rod
 
The main reason for the inline six diesel is that it's proven it's simplicity and reliability, over and over and over. Four cylinders generally require a dynamic balancer wheras the six does not... It only requires the harmonic balancer which is also simpler... and in some cases can be more efficient...
Sixes are also very scaleable... so that's another mark in their favor. Main reason to go with a V block is to save space... and at some point in time a V with more cylinders is more or less required to obtain higher power ratings from a medium/high speed engine.

Rod
 
Wasn't the question.

The LS series gasser would last hundreds of hours but not as long as the diesel between overhauls.
The work performed per lb of gasoline would likely be less than the work per lb of diesel.
 
absolutely wrong about comparing the two ,torque on the n engine will be MUCH MUCH greater!EVERY TIME!!!! simply because it has a longer throw on the crankshaft! look again at your torque curve ,and hp curves,and the way they build up and work.more rpm =equals more hp in most cases, ever wonder why a race car is set up to run higher rpms?.torque builds up to a certain point,generally around 2000-2800 rpm on a normally aspirated gas engine ,and then falls off as rpm increases.which is why we shift gears,limit rpms to highest torque, etc etc.most economic operation of ANY internal combustion engine comes at the peak of torque curve ,not hp curve.
 
You can't cheap the laws of physics. Plug the numbers into the formula and see.
Contrary to the feeling of many. 100lb ft of torque at 3000rpm. Makes exactly the same amount of power as 300lb ft of torque at 1000rpm.
Many people get confused with "torque rise" when an engine is overloaded and lugged. They think the engine has become more powerful, which it has not become more powerful. Less work is being peformed per hour when lugged to peak torque vs. when operated at peak HP rpms.
As for long stroke vs. short stroke? Peak torque occures at the rpms where peak volumetric effeicency occurs.
Take the same heads cam, manifolds etc eg a small block Chevs. A long stroke small bore 265 from the early 1980's and dyno the engine.
Transplant everything onto a different short block with a large bore 4" bore and a crankshaft destroked to make 265cu ".
Much to most peoples shock, the large bore, short stroke engine will make the same HP and torque.
What you are lossing in stroke leverage you are making up in more piston surface area for combustion pressure to push against.
 
You must log in or register to reply here.

Similar threads

J
VFD vs rotary phase converter
2
Replies
20
Views
9K
Paul in MN
P
C
Roosa Master info
2
Replies
25
Views
2K
Fixingfarmer
Fixingfarmer
Tony in SD
Machinery Delivery Memory
2
Replies
37
Views
918
K Effective
K
L
Ford 535 Loader Tractor (Looking for input)
Replies
4
Views
194
lkell93
L
Tgrasher
Always on the hunt
Replies
16
Views
659
Don Rudolph
D
Tractor Parts Tractor Manuals

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Copyright © 1997-2024 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters
Website Accessibility Policy

Back
Top