AndrewG:
Thats a specialist off road vehicle nothing to do with haulage and the power required from its V16 detroit 2 stroke would be for its pumps at 2000gpm…the power to move it would be secondary…
I said I’m familiar with the types of power in question and yes they were actually driven on the road from where we built them to Chobham and locally for testing and the shippers when finished.While the ‘power to move it’ was exactly the same motor as used to run the pump with the PTO actually being rated a lot less than the engine’s full power used to ‘move it’.
Although having said that I’d have thought that you’d have found the types of ‘power to weight ratio’ stated for other types,based on road chassis,( Bedford TM ),more impressive.IE 300 + in a 16 tonner refinery tender would still make your 570 44 tonner look really silly even with let alone without a limiter.
300hp in a 16tonner yes is a very high power to weight ratio but even so would be very much down on torque compared to modern stuff. My old 300hp F10 ‘only’ had around 1080 nm or about 800lb ft of torque thats around 40% what i currently have…
AndrewG:
300hp in a 16tonner yes is a very high power to weight ratio but even so would be very much down on torque compared to modern stuff. My old 300hp F10 ‘only’ had around 1080 nm or about 800lb ft of torque thats around 40% what i currently have…
Firstly it’s clear that around 800 lb/ft in a 16 tonner ( more in the case of 6v92t spec for example ) is going to take something like a 750 at 44t to beat if not match it.While even the almost 50 lb/ft per tonne of the larger vehicles wasn’t far behind that.
While in the real world there’s obviously a big difference between late 1970’s/early 1980’s to late 1980’s/90’s with the pace of development being massive over that period.While even at worse the difference is only in the 10 kmh range regards overall average speeds even in the worst case sub 30 lb/ft per tonne type torque to weight ratios of the late 1970’s/early 80’s.Seemingly confirmed by the road test results from the day which are available within the CM archives.
Bearing in mind that even today around 450 is probably a more common spec than 500 + with around 35 lb/ft per tonne torque to weight ratios to match.While unlike in the real world CM’s road tests in the day obviously didn’t reflect the type of widespread real world let’s say ‘relaxed’ attitudes to speed limits possible before speed limiters on the flat.Or possibly a higher balance in favour of more motorway running.
The biggest difference today arguably being that of fuelling and turbocharging technology resulting in improved specific torque outputs and a better ‘spread’ of torque across the lower engine speed range and resulting fuel efficiency increases.
Carryfast:
The biggest difference today arguably being that of fuelling and turbocharging technology resulting in improved specific torque outputs and a better ‘spread’ of torque across the lower engine speed range and resulting fuel efficiency increases.
^
This
Common rail technology along with very much higher pressure electronic staged injection and variable vane turbos, VVT ect gave a huge increase in torque outputs…
Carryfast:
The biggest difference today arguably being that of fuelling and turbocharging technology resulting in improved specific torque outputs and a better ‘spread’ of torque across the lower engine speed range and resulting fuel efficiency increases.
^
This
Common rail technology along with very much higher pressure electronic staged injection and variable vane turbos, VVT ect gave a huge increase in torque outputs…
Yeah and they also made them ridiculously complicated and expensive to repair! The lorry of today is over engineered IMHO, I’ve been driving long enough that I don’t expect to go up hills at the same speed I can do on the flat, a bit more simplicity and ease of repair would be a good trade off for that I reckon.
This common expensive and difficult to repair opinion didn’t really bear out in reality. Back in the day if you had an intermittent fault you’d have to hope it happened while at the workshop, and it never did, but with modern stuff you plug in the computer and it’ll tell you what happened exactly when and how to rectify. The only expensive aspect of maintaining new trucks is the £10k+ to buy a diagnostics computer. We also forget that trucks now are much much more reliable
Taking of power though it’s interesting how the average power went up and up, 280 320 360 380 400 420 480 etc but for at least 10 years now 440 - 480 has remained the average. Will the average go up again or is the 480 the perfect compromise between power and fuel? I’m talking average as in most lorries on the road.
No Newmercman it is just that you are paying all the bills, while the thread is seeing some comments focussed more on the performance aspect. If vehicles consistently required more driver input to achieve that performance we might see fewer rear enders.
newmercman:
Yeah and they also made them ridiculously complicated and expensive to repair! The lorry of today is over engineered IMHO, I’ve been driving long enough that I don’t expect to go up hills at the same speed I can do on the flat, a bit more simplicity and ease of repair would be a good trade off for that I reckon.
Or maybe I’m turning into a grouch…
I can honestly say ive not had a single problem with my current FH and i do very long distance work. I always have the oil changed at half the recommended interval though and only use the very best fully synthetic, keeps the inside of the engine clean, runs clean and gives the turbo longevity ive found. As for electrical gremlins, as switchlogic mentions, just plug a code reader into the OBD port and it will give any faults and exactly where to look. A big improvement on the old trial and error method, sometimes replacing parts which werent needed.
Btw- i like going up hills at the same speed as the flat, more power the better
switchlogic:
This common expensive and difficult to repair opinion didn’t really bear out in reality. Back in the day if you had an intermittent fault you’d have to hope it happened while at the workshop, and it never did, but with modern stuff you plug in the computer and it’ll tell you what happened exactly when and how to rectify. The only expensive aspect of maintaining new trucks is the £10k+ to buy a diagnostics computer. We also forget that trucks now are much much more reliable
Yes and no. My current 2 year old fh has been woefully unreliable. It’s lost about 8 days service to defects over the past 2 years, and that’s without the regular servicing and 4 call outs to the side of the road where action service have got me back up to speed. Although older trucks needed a rebuild every 3 or so years, these are more reliable in that respect. But a Friday afternoon motor is much more of a problem now. And the fault diagnostics are still the same now. If it’s not showing the fault when you are in the workshop, they won’t touch it, as they don’t want to do the warrenty work. As soon as they’re out of warrenty they will do every last little problem, then stick you a massive bill.
What I don’t miss about old trucks is the lack of weighloaders. Until a few years ago I was given an oversize tipper body with a silly metre stick stuck to the sides that I was meant to judge how much muck I could carry. I would have to stand on the ladder and watch as the machine swung over or near me.
When you “left with half a load on” you got banned from site and then had grief from the TM, especially if you were underweight when weighed. ■■■■■■ told me off for running a ton light when we were paid by the load.
Carryfast:
The biggest difference today arguably being that of fuelling and turbocharging technology resulting in improved specific torque outputs and a better ‘spread’ of torque across the lower engine speed range and resulting fuel efficiency increases.
^
This
Common rail technology along with very much higher pressure electronic staged injection and variable vane turbos, VVT ect gave a huge increase in torque outputs…
Yeah and they also made them ridiculously complicated and expensive to repair! The lorry of today is over engineered IMHO, I’ve been driving long enough that I don’t expect to go up hills at the same speed I can do on the flat, a bit more simplicity and ease of repair would be a good trade off for that I reckon.
Or maybe I’m turning into a grouch…
There’s probably no way back from the idea of electronic fuelling combined with mechanical injector actuation of the relatively older tech engines to provide anything like the required fuel efficiency even at 1980’s type fuel costs.As I’ve said previously I think the N14 is probably as good as it gets in providing an all round package of torque output,reliability and ease of maintenance.
switchlogic:
This common expensive and difficult to repair opinion didn’t really bear out in reality. Back in the day if you had an intermittent fault you’d have to hope it happened while at the workshop, and it never did, but with modern stuff you plug in the computer and it’ll tell you what happened exactly when and how to rectify. The only expensive aspect of maintaining new trucks is the £10k+ to buy a diagnostics computer. We also forget that trucks now are much much more reliable
If it wasn’t for having bullet proof warranty cover ask nmm whether he’d prefer an N14 in his truck or D13 etc etc etc bearing in mind he’d be paying the maintenance bills.
switchlogic:
Taking of power though it’s interesting how the average power went up and up, 280 320 360 380 400 420 480 etc but for at least 10 years now 440 - 480 has remained the average. Will the average go up again or is the 480 the perfect compromise between power and fuel? I’m talking average as in most lorries on the road.
It’s all about the torque output not the power output in which case the discussion with Andrew G regards torque to weight ratios was on the right lines.In which case at normally accepted speeds around 30-35 lb/ft per tonne is probably good enough.While in terms of output again in many cases we’re going backwards from that of the N14.
