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terex herder

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The reason your 350 horsepower pickup engine can't replace a 350 horsepower 855 is duty cycle. The pickup engine can't sustain full power for very long before components start to overheat. A heavy duty diesel is rated to develop full rated power for 10,000 hours straight. Your pickup maybe good for 10 minutes straight before it starts to get hot, only a couple of minutes if you have it chipped. Even overfueled heavy diesels have to be driven by the pyrometer if you don't want them to melt down.
 

Spud_Monkey

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Horsepower is how fast you hit the wall, τ is how far you go through the wall. A mating black fly can go 90 mph chasing it's mate, I'm sure if it crashes into you, you will live to squish it unlike a train going 90 mph you won't live cause it will squish you.
Horsepower sells, τ gets the job done...
τ is the Greek word tau meaning torque.
 

Truck Shop

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I’ve been watching him since he started on this so far he’s trying to use all off the shelf parts so the large manufacturers will stay away since there is no proprietary parts for them to hold hostage he posts on tik tok fairly regularly

That's Good, but someone with a lot more cash could run over the top of him. It happens everyday.
 

Truck Shop

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Some years back I had a formula for brake horse power in a KW manual. It showed using all 350 hp
climbing a 6% grade at 20 mph what it took to keep it under control going down a 6% grade at 20.
The kinetic energy could boil a bath tub full of water in 3 seconds. Wish I could find that info, lost it.
 

Acoals

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The reason your 350 horsepower pickup engine can't replace a 350 horsepower 855 is duty cycle. The pickup engine can't sustain full power for very long before components start to overheat. A heavy duty diesel is rated to develop full rated power for 10,000 hours straight. Your pickup maybe good for 10 minutes straight before it starts to get hot, only a couple of minutes if you have it chipped. Even overfueled heavy diesels have to be driven by the pyrometer if you don't want them to melt down.

... Just because you can squeeze 450hp/1000lb of torque out of 6.7 litres doesn't mean you should ...
 

Old Doug

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Hauling scrap iron for almost 30 years with my 1967 GMC pickup 350 engine . Getting to haul with alot of other guys with alot of different engines was interesting. My pickup always did the job but i never thought it was any thing special till after i ran with 460,454, 383 and early diesel pickups i found out it pulled alot better than i thought . A good engine with the right gears is hard to beat. It meet its match one day it was burning oil on number 8 cylinder i was pushing it hard trying to keep up with a Duramax . I burnt a valve on number 8 and melted a hole in the exhaust manifold. If i would have had a gear between 3 and 4 it would have done better.
 

56wrench

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Horsepower gets the truck/car down the road. Torque gets it up the hill is how i was taught. Smaller displacement internal combustion engines can do the same job with lower rotating mass and inertia but need a transmission with more gear selection to keep the engine operating in its relatively narrow powerband because thats where they are the most efficient.
 

Delmer

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A electric drive at 0 rpm has it's most torque, the faster it goes the less power it has. When a ev truck is at highway speeds it will be at it's lower power rating, hence my saying of electric hp is different than diesel hp.
You're wrong and it sounds like you're confusing terms. An electric motor at 0 RPM is producing 0 power, power is measured in HP or watts. At very motor speed, any motor will still be producing relatively low power, even if it's producing very high torque. At highway speeds passing or climbing a hill is when any vehicle needs the most power/HP, and an electric drive will have to produce that power also, or slow down.

The steam analogy is good only in that steam is a similar power storage to a battery, the limiting short term reserve that powers the motor. A steam engine could be replaced with an electric, or gas or diesel of the same HP and do the same thing with the traction engine of the same weight and other specs.

Your comparison of a pickup engine in a semi is getting back to the duty cycle. A semi engine is designed to operate at a mid duty cycle for long hours. A pickup will get a high HP rating, but low duty cycle, and lower expected life. A dragster engine is the other extreme. HP is HP. Torque curve, engine reliability/duty cycle are different. Electric motors have more useful torque for many purposes, but you can't say the HP is different.
 

Tones

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Yep

Like the old engine builders say: "There is only so many horsepowers in that engine son. The faster you let them out, the sooner I have to take it apart and put them back in".
The old engine builder I was around expression's, there is no substitute for cubic inches. That still holds true today
 

cfherrman

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You're wrong and it sounds like you're confusing terms. An electric motor at 0 RPM is producing 0 power, power is measured in HP or watts. At very motor speed, any motor will still be producing relatively low power, even if it's producing very high torque. At highway speeds passing or climbing a hill is when any vehicle needs the most power/HP, and an electric drive will have to produce that power also, or slow down.

The steam analogy is good only in that steam is a similar power storage to a battery, the limiting short term reserve that powers the motor. A steam engine could be replaced with an electric, or gas or diesel of the same HP and do the same thing with the traction engine of the same weight and other specs.

Your comparison of a pickup engine in a semi is getting back to the duty cycle. A semi engine is designed to operate at a mid duty cycle for long hours. A pickup will get a high HP rating, but low duty cycle, and lower expected life. A dragster engine is the other extreme. HP is HP. Torque curve, engine reliability/duty cycle are different. Electric motors have more useful torque for many purposes, but you can't say the HP is different.

Stall out a electric motor and measure it's amps and convert to watts

The pickup engine is only mentioned that people were saying earlier in the thread a 300 HP electric motor would act the same as a 300 hp diesel because hp is HP, which is why I mentioned a pickup engine in a semi.

The HP is very extremely different. I would rather take a 300 HP electric motor over a 500 HP big diesel any day.
 

Delmer

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That's the difference between consumption and production. HP or power or KW, are all measured by force times distance per unit of time, that is 33,000 foot pounds per minute or similar. Stall out any machine, and that is technically producing zero output no matter the torque, torque times zero is still zero.

An engine can behave differently, but 300 HP is 300 HP, whether it's gas, electric or unicorn farts. Depends on what you want it to do which one will work better.
 

cfherrman

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So when an electric motor is load holding something from going down, and it's not moving, it is not producing power?

Dude good luck, things on paper are not the same in the rear world.
 

Truck Shop

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An electric motor not turning holding a load is in static mode, basically locked up. No torque or horse power
is being generated.
 

colson04

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Hang on guys, a stalled electric motor is producing torque. It is known as Stall torque. The amperage going in to a stalled motor can be measured and if a load meter where applied to a stalled motor, a torque can be measured. What that means is you applied a load equal to, or greater than, the torque capacity of a given motor. Reduce load applied to motor and it will start turning. Horsepower goes to 0 because there is no longer any work being accomplished as the load and motor are at zero rpm. This a bad state for an electric motor though as it produces an extreme amount of heat. The amperage (energy) coming in is still being consumed by the motor to produce the max torque/stall torque, but is no longer being converted to mechanical energy since rotation is zero. In this state, all of that energy gets converted to heat and can overheat an electric motor very quickly, leading to failure of the windings.

If you reach stall torque on a combustion engine, it stalls and quits running. No more energy going in, no more output.
 

terex herder

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Please describe how your electric motor is load holding, I'm not familiar with that application. Sounds more to me like electric brake mode.
 

Delmer

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So when an electric motor is load holding something from going down, and it's not moving, it is not producing power?

Dude good luck, things on paper are not the same in the rear world.

Exactly, there is no power produced without movement of the output. That's part of what I've been saying.

If you can't describe things correctly on paper, then you won't be correctly describing how things work in the real world either.
 

DMiller

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Electrical mechanisms in a locked rotor state do not play well, are as such unforgiving. Heat, eventual fault and failure are forthcoming. As noted fuel engines stall they stop producing everything, heat fuel consumption and torque yet add rolling resistance to hold vehicle at rest, electric motors unless fielded as to present a generator will free roll.
Think on a locked engaged starter, even as a electrical motor can spin really fast if oversped and working to resist rotation can literally shred themselves in a burn down.
 
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Delmer

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Grab the shaft of an electric motor, don't let it turn and apply power to the motor. Tell me it's not producing any torque.
TS said " no torque... ...being generated" which is debatable. NO POWER is being produced. The torque is there, just no movement, so no power. You could say there is no torque OUTPUT, that's not what I'm arguing.

An electric drill will have a torque curve, and a power curve, just like any electric, diesel, gas or unicorn fart engine. I'd bet the power will be highest nearer to full speed than low speed. Even a solar panel has a power curve, it's not max amps and it's not max volts, search MPPT.
 
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