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Old 03-21-2005, 05:12 AM   #61
the lobster
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Quote:
Originally Posted by tbaxleyjr
what is the big hairy deal here - all of my car manuals call give torque specs in ft-lbs while the engineering texts I used in engineering school called it lbf-ft (pounds force/ft). For all practical purposes, it means the same thing. We are becoming too "overtorqued" about this.
torque is described a TWISTING rotary force rotating on an axis.FORCE is ENERGY APPLIED.The explosion causes downward force on the piston,and it is the crankshaft that coverts it to TORQUE.
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Old 03-21-2005, 05:17 AM   #62
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Quote:
Originally Posted by the lobster
torque is described a TWISTING rotary force rotating on an axis.FORCE is ENERGY APPLIED.The explosion causes downward force on the piston,and it is the crankshaft that coverts it to TORQUE.
There is no explosion. There is combustion. An explosion is uncontrolled combustion. I can assure you that what happens inside of a properly running engine is controlled combustion... Otherwise for example the area above the piston would be called the explosion area.

Thank you for working on your spelling, now you just need to realize that words mean things. And don't bother with the lame excuse "you know what I mean". I only know what you said and I'm not married to you.
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Old 03-21-2005, 05:35 AM   #63
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Its Still Foot-pounds

Quote:
Originally Posted by windsonian
WORK is done when a force (or torque) moves an object through a distance (ie Fxd)
TORQUE is a twisting force applied by a linear force acting at a distance (radius) from the pivot point (ie Fxd)

So the equations, and hence the units (lb-ft or whatever you want to use), look the same too - eventhough the two distances being multiplied are different.

Basic example showing differences:
Torque a nut with a 0.5m long socket wrench (long I know, but easier for calcs)
Apply 10 Newtons (approx 2.25lb I think) of force at the end of the wrench to tighten the nut.
With this much force, the nut travels 1 revolution before stopping (more force would tighten it more, but we're stopping at 10N)

The TORQUE applied to the nut is 10N x 0.5m = 5Nm (approx 3.7lb-ft I think)

To rotate one revolution, the end of the socket wrench has travelled 2 x pi x r = 2 x pi x 0.5 = 3.14m (approx 10.5 ft I think)

Therefore, the WORK done to move the force through this distance is 10N x 3.14m = 31.4 Nm (approx 23.2 lb-ft I think)

So change your lb.ft to ft.lb or whatever if you want .... but as you can see, even though the units are similar, WORK and TORQUE are not the same.
I AGREE.TORQUE IS A FORCE APPLIED IN A RADIAL APPLICATION.
WORK IS APPLIED IN A LINEAR,NON LINEAR,AND EVEN STATIC APPLICATION.
ONE OF NEWTONS LAWS,(for each reaction there is an equal and opposite reaction.,has some wierd implications:If a train is pushing a car backwards down a train track,but the car is spinning it's wheels,AND THE TRAIN HAS ITS ENGINE OFF,BUT THE 450 HP CAR IS SPINNING TIRES,it is the residual work ,called kinetic energy that is pushing the car.the torque from the engine is multiplied through the transmission,and the axle.the transfer of torque into linear motion is the friction co-efficient x the torque actually delivered to the wheel.if the transfer of energy was perfect on the tires,the kinetic energy stored in the train,produced by thousands of horsepower,will cause the output of the 450 hp to stall.eventually you end up with a negative acceleration on the car.the resistance to kinetic energy is all the forces together.train torque is measured in ft/lbs. so if there is 746 watts to a horsepower,and there is a 24000 horsepower diesel engine?how many blenders can you power with the train? FORCE CONVERTED TO TORQUE,TORQUE CONVERTED TO ELECTRICITY VIA A GENERATOR,LINEAR WORK THROUGH THE WINDINGS,BACK TO TORQUE OUT OF THE BLENDER.
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Old 03-21-2005, 05:36 AM   #64
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Quote:
Originally Posted by vwhobo
There is no explosion. There is combustion. An explosion is uncontrolled combustion. I can assure you that what happens inside of a properly running engine is controlled combustion... Otherwise for example the area above the piston would be called the explosion area.

Indeed, "explosion" is the most over-used word for vehicles. My mechanics teacher always refers to it as an explosion, I just let him be though, I enjoy knowing more about vehicles than my teacher. The engine would grenade if there was constant "explosions" in it. Gasoline does not explode, it burns.
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Old 03-21-2005, 05:52 AM   #65
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i do not like english.

Quote:
Originally Posted by DodgeRida67
You have the worst english skills... Before you say that doesn't amount to anything, it does.
OH .Thank-you.
for that brilliant composure I have this counter.I do not care for "proper" GRAMMAR or PUNCTUATION in an application such as this one.As long as the
message gets across,and obviously it does,that is all I am concerned with.I
really do not care for the opinions of others ,as far as english skills are concerned.You see,I have a secretary to do my writing for me .So in summary,I am here to see if I can help people ,not get reviews from ENGLISH 101.
THANKS
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Old 03-21-2005, 06:13 AM   #66
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ha ha ha

While I generally try to make my spelling and grammar correct (even in this sort of environment), you make a good (and amusing) case.
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Old 03-21-2005, 06:17 AM   #67
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Too Much Theory .

Quote:
Originally Posted by vwhobo
There is no explosion. There is combustion. An explosion is uncontrolled combustion. I can assure you that what happens inside of a properly running engine is controlled combustion... Otherwise for example the area above the piston would be called the explosion area.

Thank you for working on your spelling, now you just need to realize that words mean things. And don't bother with the lame excuse "you know what I mean". I only know what you said and I'm not married to you.
WOW. I did not expect such a speedy response.If you look at the time that I
have been posting replies,It is in the early hours.One is more prone to make mistakes when fatigued.Compounding the problem is the fact that I did really
not go out of my way to accomodate perfection.Thanks for the correction.
What would happen if the air fuel mixture were ignited,but the piston froze just before TDC.Would it result in an explosion.?I always thought that an explosion was a compression of molecules created by heat.An explosion is a combustion,just a different rate.If you put 2 sticks of TNT in a beer can and seal it,then light it,an explosion happens.If you submerse it under water and slow down the expansion,does it become combustion?No .It is a controlled explosion.COMBUSTION CHAMBER = combustible material mixes with oxygen
in a confined area. 'THE AIR AND FUEL ARE MIXED AND COMPRESSED.THE EXPLOSION FROM THE IGNITED AIR FUEL CHARGE IN THE COMBUSTION CHAMBER FORCES THE PISTON DOWNWARD."
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Old 03-21-2005, 04:42 PM   #68
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Quote:
OH .Thank-you.
for that brilliant composure I have this counter.I do not care for "proper" GRAMMAR or PUNCTUATION in an application such as this one.As long as the
message gets across,and obviously it does,that is all I am concerned with.I
really do not care for the opinions of others ,as far as english skills are concerned.You see,I have a secretary to do my writing for me .So in summary,I am here to see if I can help people ,not get reviews from ENGLISH 101.
THANKS

It's a free country. If you wish to remain looking as stupid as you can possibly look, go ahead and do just that. BTW, congrats, you're very good at it.



Quote:
Originally Posted by the lobster
WOW. I did not expect such a speedy response.If you look at the time that I
have been posting replies,It is in the early hours.One is more prone to make mistakes when fatigued.Compounding the problem is the fact that I did really
not go out of my way to accomodate perfection.Thanks for the correction.
What would happen if the air fuel mixture were ignited,but the piston froze just before TDC.Would it result in an explosion.?I always thought that an explosion was a compression of molecules created by heat.An explosion is a combustion,just a different rate.If you put 2 sticks of TNT in a beer can and seal it,then light it,an explosion happens.If you submerse it under water and slow down the expansion,does it become combustion?No .It is a controlled explosion.COMBUSTION CHAMBER = combustible material mixes with oxygen
in a confined area. 'THE AIR AND FUEL ARE MIXED AND COMPRESSED.THE EXPLOSION FROM THE IGNITED AIR FUEL CHARGE IN THE COMBUSTION CHAMBER FORCES THE PISTON DOWNWARD."
It's called detonation and is most definately 100% different from combustion in this context.

Last edited by DodgeRida67 : 03-21-2005 at 04:45 PM.
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Old 03-22-2005, 02:07 AM   #69
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Quote:
Originally Posted by DodgeRida67
It's a free country. If you wish to remain looking as stupid as you can possibly look, go ahead and do just that. BTW, congrats, you're very good at it.




It's called detonation and is most definately 100% different from combustion in this context.

Detonation is an uncontrolled SECOND explosion after the spark plug fires. When the spark plug fires, the air/fuel doesnt just explode all at once, it takes time to burn and when the spark happens, the air/fuel burn there and the flame than contnues down while burning more air/fuel but when detonation occures, the last part of the air/fuel explodes by itself without the initial flame hitting it. When the flame goes down to the piston, the air right on top of the piston gets hotter and hoter so it explodes by itself kinda like preignition so the explosion causes pressure waves or somthing witch makes a noise.
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Old 03-22-2005, 02:13 AM   #70
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Quote:
Originally Posted by CarEXPERT
Detonation is an uncontrolled SECOND explosion after the spark plug fires. When the spark plug fires, the air/fuel doesnt just explode all at once, it takes time to burn and when the spark happens, the air/fuel burn there and the flame than contnues down while burning more air/fuel but when detonation occures, the last part of the air/fuel explodes by itself without the initial flame hitting it. When the flame goes down to the piston, the air right on top of the piston gets hotter and hoter so it explodes by itself kinda like preignition so the explosion causes pressure waves or somthing witch makes a noise.
Look at this. We're really getting somewhere now. There is hope for the younger generation. Our very own 14 year old dope smoker has a better understanding of controlled combustion and flame fronts than the world renowned self proclaimed perfectionist and pilot, big crawdaddy.

Good on ya kiddo.
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Thanks for the pic, jedimario.

"Everybody believes in something and everybody, by virtue of the fact that they believe in something, use that something to support their own existence."
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Old 03-22-2005, 03:35 AM   #71
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torque is defined as a force x distance rotating about an axis. Any Freshman engineering student in any engineering school of decent repute is taught that concept in a class titled something like Basic Engineering Mechanics - Statics which is usually the first real engineering class taken.

From an engineering thremodynamics standpoint, explosion is really rapid combustion. What moves the piston is the rapid expansion of gasses in the cylinder caused by the increased temperature due to rapid combustion

Detonation or spark knock is simply the fuel air mixture burning when it is not supposed to. It is many causes.

I suggest discussions of subjects such as flame fronts and laminar flame speeds be discussed by someone with an adequate engineering/technical background to make sense
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