stevieboy308:
power is torque multiplied by rpm
Sorry bud, totally incorrect.
Ross.
stevieboy308:
bigr250:
Carryfast:
these days the extra power is usually obtained by having more torque not by more engine speed.Eh? most big engines these days produce maximum torque between 1,000rpm & 1,400rpm while max power is always produced well outside the ‘green zone’ on the rev counter (normally around 2,000rpm) and big power & big torque go hand in hand in large capacity (16L +) engines.
Ross.
power is torque multiplied by rpm
No it isn’t
bigr250:
stevieboy308:
power is torque multiplied by rpmSorry bud, totally incorrect.
Ross.
you sure?
fuse:
Engines are like pricks everyone wants a bigger one
Speak for yourself 
stevieboy308:
bigr250:
stevieboy308:
power is torque multiplied by rpmSorry bud, totally incorrect.
Ross.
you sure?
They’re proportionally related but you would have to make an adjustment by some factor depending on circumstances.
I’ve seen a Volvo pulling a grain bulker, I think, round Somerset that’s got 700 on the cab. I’m guessing it’s been stuck on later.
I had a 220 hp 4 pot engine with a 6 ft diameter flywheel and once it got up to full speed of 311 rpm the torque was astronomical in relation to the hp.
Couldn’t give a toss about horsepower. Ive got a 480 never run over 40tons and its fine, rarely go over 1500rpm even on steep hills.
fuse:
I saw a six axle artic tipper the other day the driver said payload was 27 tonnes, what good is that,still they look good
Rubbish when bulk work is paid by the tonne! For me the more the merrier but when i put sensible head on personally i think 500/520 is enough for bulk or livestock work,460 for general and leave the big toys to low loader work.Having that bit extra can help mpg unless you drive it like you stole it.
Tourqu is the abillity to make things turn there for you could say have a strate 6 16ltr engine put it up against a 13ltr v8 the v8 will mach or out proform the strate 6 as the greater number of pistons will give it better torqu but it also go of the gearing from the gearbox though to the final drive as you csn reduce and in crease tourqu at the wheels via gearing now sleep.
stevieboy308:
bigr250:
stevieboy308:
power is torque multiplied by rpmSorry bud, totally incorrect.
Ross.
you sure?
Oh yes. Torque is a twisting force measured as a mass (weight) in KG’s (or N newtons) over a distance ‘M’ normally delivered over a wide range of engine speed, the torque is the ‘usefull’ power of a diesel engine & the rpm range in which it’s delivered is normally the economy range. The max power is always at the top end of the rev range and in most cases would only be used when working at it’s hardest as the engine will literally drink fuel when revving so hard, personally I never rev an engine so high.
Ross.
Angus25:
Tourqu is the abillity to make things turn there for you could say have a strate 6 16ltr engine put it up against a 13ltr v8 the v8 will mach or out proform the strate 6 as the greater number of pistons will give it better torqu but it also go of the gearing from the gearbox though to the final drive as you csn reduce and in crease tourqu at the wheels via gearing now sleep.
Then why has the R620 (16L) V8 got 3000NM of torque when the F16 750 (16L) “straight six” puts out 3,550NM?
Kinda destroys your point eh??
Ross.
bigr250:
stevieboy308:
bigr250:
stevieboy308:
power is torque multiplied by rpmSorry bud, totally incorrect.
Ross.
you sure?
Oh yes. Torque is a twisting force measured as a mass (weight) in KG’s over a distance ‘M’ normally delivered over a wide range of engine speed, the torque is the ‘usefull’ power of a diesel engine & the rpm range in which it’s delivered is normally the economy range. The max power is always at the top end of the rev range and in most cases would only be used when working at it’s hardest as the engine will literally drink fuel when revving so hard, personally I never rev an engine so high.
Ross.
so what was totally incorrect about what i said?
as i said fella, power = torque times revs and to put the units of power into bhp ---- bhp = torque in lb/ft x rpm then divide by 5252
bigr250:
Angus25:
Tourqu is the abillity to make things turn there for you could say have a strate 6 16ltr engine put it up against a 13ltr v8 the v8 will mach or out proform the strate 6 as the greater number of pistons will give it better torqu but it also go of the gearing from the gearbox though to the final drive as you csn reduce and in crease tourqu at the wheels via gearing now sleep.Then why has the R620 (16L) V8 got 3000NM of torque when the F16 750 (16L) “straight six” puts out 3,550NM?
Kinda destroys your point eh??
Ross.
Could be down to tuning Ross perhaps for fuel economy or driveline reasons ■■
bigr250:
Angus25:
Tourqu is the abillity to make things turn there for you could say have a strate 6 16ltr engine put it up against a 13ltr v8 the v8 will mach or out proform the strate 6 as the greater number of pistons will give it better torqu but it also go of the gearing from the gearbox though to the final drive as you csn reduce and in crease tourqu at the wheels via gearing now sleep.Then why has the R620 (16L) V8 got 3000NM of torque when the F16 750 (16L) “straight six” puts out 3,550NM?
Kinda destroys your point eh??
Ross.
for one there are plenty of variables for a proper comparison, but generally 2 engines of the same size with the same spec but 1 a straight 6 and one a v8, the straight 6 will have higher torque due to the greater leverage on the crack because of the crank’s larger radius due to the longer stroke, but the v8 will rev higher due to the lighter engine internals and as it’s torque x rpm that gives power, it may produce more power
stevieboy308:
bigr250:
Angus25:
Tourqu is the abillity to make things turn there for you could say have a strate 6 16ltr engine put it up against a 13ltr v8 the v8 will mach or out proform the strate 6 as the greater number of pistons will give it better torqu but it also go of the gearing from the gearbox though to the final drive as you csn reduce and in crease tourqu at the wheels via gearing now sleep.Then why has the R620 (16L) V8 got 3000NM of torque when the F16 750 (16L) “straight six” puts out 3,550NM?
Kinda destroys your point eh??
Ross.
for one there are plenty of variables for a proper comparison, but generally 2 engines of the same size with the same spec but 1 a straight 6 and one a v8, the straight 6 will have higher torque due to the greater leverage on the crack because of the crank’s larger radius due to the longer stroke, but the v8 will rev higher due to the lighter engine internals and as it’s torque x rpm that gives power, it may produce more power
quite right stevieboy the straight 6 will have a longer stroke as a rule
stevieboy308:
bigr250:
stevieboy308:
bigr250:
stevieboy308:
power is torque multiplied by rpmSorry bud, totally incorrect.
Ross.
you sure?
Oh yes. Torque is a twisting force measured as a mass (weight) in KG’s over a distance ‘M’ normally delivered over a wide range of engine speed, the torque is the ‘usefull’ power of a diesel engine & the rpm range in which it’s delivered is normally the economy range. The max power is always at the top end of the rev range and in most cases would only be used when working at it’s hardest as the engine will literally drink fuel when revving so hard, personally I never rev an engine so high.
Ross.
so what was totally incorrect about what i said?
as i said fella, power = torque times revs and to put the units of power into bhp ---- bhp = torque in lb/ft x rpm then divide by 5252
Nothing, the only minor nitpick would be power (in watts) is the product of torque (in Nm) and angular velocity (in rad per second). You need to convert RPM to angular velocity or you would grossly overstate the engine power. Makes no difference though when comparing which is the more powerful of two engines as long as everything is measured in the same units.
here you go, a dyno graph from my old car. have a look on the torque graph, times the torque by the rpm at any given point then divide it by 5252 and see where you end up on the power graph 
stevieboy308:
so what was totally incorrect about what i said?as i said fella, power = torque times revs and to put the units of power into bhp ---- bhp = torque in lb/ft x rpm then divide by 5252
So where does 5252 come from, is it only a constant when torque is measured in imperial (ft/lb’s) against power in BHP? what fugure do you use when measuring the torque in the metric measurement of kg/m against power in BHP or PS, then what constant would be applicable when meassuring the torque in N/M against power measured in KW’s??
Ross.
Moose:
quite right stevieboy the straight 6 will have a longer stroke as a rule
& as a rule in engine design longer stroke = greater torque.
bigr250:
Moose:
quite right stevieboy the straight 6 will have a longer stroke as a rule& as a rule in engine design longer stroke = greater torque.
quite right