ERF-Continental:
Some input from respectively a 1981 overview on construction and industrial as well as an article
in 1982 Fleet Owner on the Big Cam…enjoy reading!
The Fleet Owner article contains some interesting details, specifically the power output of the two engines. If I remember correctly, the Big Cam E400 was launched in Europe around that time (1980-1982 ish), with peak torque at 1400rpm and peak power at 2100rpm (There is an article about it posted somewhere on TNUK, possibly by me(!) but, with the proliferation of different threads, I doubt I will find it again). Maybe the initial European engine was a Big Cam 2? Real ■■■■■■■ men will know better!
ERF-Continental:
Some input from respectively a 1981 overview on construction and industrial as well as an article
in 1982 Fleet Owner on the Big Cam…enjoy reading!
Where is the advantage in producing 400 hp at 2,100 rpm when it can do it at 1,900.While the description says less torque rise when it’s actually just the same peak torque at the same engine speed with less torque drop at peak power therefore less engine speed required.The idea that the lower engine speed means less road speed is also erroneous being that the power output is the same and is what matters.
IE the ‘Formula’ option was obviously the one to go for and it’s surprising that anyone would have bothered with the higher engine speed option.
ERF-Continental:
Some input from respectively a 1981 overview on construction and industrial as well as an article
in 1982 Fleet Owner on the Big Cam…enjoy reading!
Where is the advantage in producing 400 hp at 2,100 rpm when it can do it at 1,900.While the description says less torque rise when it’s actually just the same peak torque at the same engine speed with less torque drop at peak power therefore less engine speed required.The idea that the lower engine speed means less road speed is also erroneous being that the power output is the same and is what matters.
IE the ‘Formula’ option was obviously the one to go for and it’s surprising that anyone would have bothered with the higher engine speed option.
The 2100rpm version will likely carry the penalty of increased fuel consumption in service, due to drivers using the extra engine speed for fun. This may also impinge on the durability of the engine. On the other hand, the wider speed range of the 2100rpm engine will reduce the need for gearchanges. A 9 speed gearbox may suffice, whereas a 13 speed may be necessary with the 1900rpm engine.
An owner driver would choose the 2100rpm version every time, based on these arguments. ■■■■■■■ were catering for that market, in offering the 2100rpm engine. You must always consider the undeniable fact that the manufacturer knew what it was doing.
ERF-Continental:
Some input from respectively a 1981 overview on construction and industrial as well as an article
in 1982 Fleet Owner on the Big Cam…enjoy reading!
Where is the advantage in producing 400 hp at 2,100 rpm when it can do it at 1,900.While the description says less torque rise when it’s actually just the same peak torque at the same engine speed with less torque drop at peak power therefore less engine speed required.The idea that the lower engine speed means less road speed is also erroneous being that the power output is the same and is what matters.
IE the ‘Formula’ option was obviously the one to go for and it’s surprising that anyone would have bothered with the higher engine speed option.
The 2100rpm version will likely carry the penalty of increased fuel consumption in service, due to drivers using the extra engine speed for fun. This may also impinge on the durability of the engine. On the other hand, the wider speed range of the 2100rpm engine will reduce the need for gearchanges. A 9 speed gearbox may suffice, whereas a 13 speed may be necessary with the 1900rpm engine.
An owner driver would choose the 2100rpm version every time, based on these arguments. ■■■■■■■ were catering for that market, in offering the 2100rpm engine. You must always consider the undeniable fact that the manufacturer knew what it was doing.
The idea of any owner driver with any sense wanting to take it up to 2,100 rpm instead of short shifting it at 1,900 all for the added ‘pleasure’ of speccing a 9 speed box instead of 13 makes equally no sense to me.
Bearing in mind that the difference in fuel consumption and/or potential durability issues could mean the difference between survival or bankruptcy for an owner driver v just a financial headache for a big fleet operator.
While I don’t think that the engine would see any difference between 2,100 rpm for ‘fun’ or to pointlessly cater for the ‘wrong’ box spec.IE needles wear and tear and fuel use in either case.
I never realised they revved that high, the small cams we had in Guy’s and Sed Atki’s were running at nearly 60mph at 1400 rpm, you would have been going at some serious speed at 2100 !
Trev_H:
I never realised they revved that high, the small cams we had in Guy’s and Sed Atki’s were running at nearly 60mph at 1400 rpm, you would have been going at some serious speed at 2100 !
Firstly by the standards of North American speeds,at least in the day,60 mph would be classed as hanging about.While 32t gross max combined with just UK terrain probably resulted in higher gearing being used than would otherwise be the case in the 35-40t + American or Euro environment.
newmercman:
For crying out loud, nobody with half a brain would run their engine at max rpm all day long.
Here we go with another load of utter ■■■■■■■■ on how everybody was doing it wrong.
Yes it goes without saying that no one is going to run an engine at peak power on a sustained basis.That still doesn’t change the fact that no one with half a brain would run something up to 2,100 rpm that provided its peak power output at 1,900.
As for the example of almost 60 mph at 1,400 rpm the usual idea is to gear it for maximum required speed on the flat at around peak torque.Which is why anyone who wanted to run at 80-90 mph ‘all day’ would have gone for a KTA rather than a 14 Litre.However for those who didn’t it’s obvious that peak torque on a 14 litre small cam won’t be enough for silly speeds.
newmercman:
For crying out loud, nobody with half a brain would run their engine at max rpm all day long.
Here we go with another load of utter ■■■■■■■■ on how everybody was doing it wrong.
But isn’t that what we did (almost) when the vehicles were geared to less than 60mph? The Gardners could put up with it because of their low governed speed, but the likes of the AECs and Leylands certainly didn’t like 2200 - 2400 rpm hour after hour. Granted they probably weren’t on full load as well as full revs all that time, but they were certainly riding the governor for much of the day.
newmercman:
For crying out loud, nobody with half a brain would run their engine at max rpm all day long.
Here we go with another load of utter ■■■■■■■■ on how everybody was doing it wrong.
But isn’t that what we did (almost) when the vehicles were geared to less than 60mph? The Gardners could put up with it because of their low governed speed, but the likes of the AECs and Leylands certainly didn’t like 2200 - 2400 rpm hour after hour. Granted they probably weren’t on full load as well as full revs all that time, but they were certainly riding the governor for much of the day.
As I said, nobody with half a brain…
Why on earth would you gear a lorry at less than 60mph and put it out on 60mph roads? Perhaps carryfast has been right all along when he slags off the British Haulier that buried their head in the sand and refused to move with the times.
Expecting the same reliability from a drive train specced to 1950s requirements in the much faster paced 60s and 70s was a bit optimistic to say the least.
I am confident that if you trawl back through CM road tests for the early 1970s you will find that a significant number of the vehicles tested were unable to exceed or even reach 60 mph. Top speed was regularly recorded to be somewhere between 53 and 57 mph. In some cases this occasioned comment from the tester - normally drawing attention to the fact that without the low gearing the vehicle would have been unable to tackle the steeper hills on the A68 southbound. I can think of at least one test report (below Merc LPS 1418) mentioning that a diversion via Newcastle had to be taken because of the vehicle’s proven inability to restart on a 1 in 6 incline. At the time the 6 bhp/ton minimum requirement had either just come in or was about to do so. I have some old early 1970s CM road tests :
1)A Ryder owned Foden S40 with a derated NH250 which could only reach 57 mph. Unusually for the time this test was conducted using a 40ft tilt rather than a flat trailer.
2) Seddon 32.4 Rolls 220 57 mph
3) Merc LPS 1418. 54mph
4)AEC Mandator 53 mph
5)Atkinson Borderer 8lxb 53 mph
6)ERF A series Cu220 57mph
This was the period when virtually everything had either hub reduction, double reduction diffs or two speed axles.
As someone who drove '70s lorries I do remember that travelling at maximum speed was a very transient thing. Britain is a very hilly country with many sharp climbs and very few gradual ones. Those old engines were great on the straight flat out at 60 mph plus but the slightest incline caused massive reductions in speed and before you knew it you were down fistfuls of gears and crawling up the next bank at 12 mph. We quickly forget how normal this was, even in the early '80s. And it wasn’t just British lorries. I remember climbing up motorway hills at these low speeds in 192bhp MANs, 190bhp Mercs and so on; then belting down the other side at 70 or 80 mph. That’s how it was before big power, big torque and big bhp. Robert
I remember the period, from the passenger seat only, but rven so, a trip to S Wales in a Mandator was a longer, noisier and more uncomfortable trip than it was in an F88.
The Mandators, Beavers and Gardner powered Atki sand Scammells that were once the mainstay of the fleet were succeeded by F88s and within a short space of time there was a new XJ6 in the boss man’s ■■■■■■■■■■■■.
Now this wasn’t a run of the mill general haulage firm with handball and roping and sheeting taking up a large part of the working day, but a tanker operation from London to S Wales and Scotland, so the higher average speeds did indeed improve efficiency and profitability.
It would probably be fair to say that serious final drive reduction was often used to compensate for the abysmal lack of specific torque output of early generation naturally aspirated engines.On that note it probably would have been better to express the output requirement legislation on a torque output per tonne basis.Bearing in mind that the solution to the power output issue was often just a case of more engine speed and hope that the torque curve wouldn’t drop at faster rate than the engine speed one increased.Obviously none of which helped to solve the hill climbing performance v high speed running equation.
The leap in engine design which provided figures like 400 hp at 1,900 rpm being the point in this case which took place over a relatively short period of time.The question then being why defeat the object of that by going back to more engine speed than needed in that new game changing environment.
It was surprising the difference in performance between our Foden Haulmaster’s with the Gardner 201/ Fuller nine speed/ Foden worm and wheel diffs and our Sed Ak 400’s with the same engine/gearbox but with the Eaton back end. Those worm and wheel diffs must have absorbed a lot of power?
I recall the Foden in my avatar pic doing around 1600 rpm at 60 mph (Rolls 265Li) but the engine only revved at 1950 maximum the same as our Gardners so was a little sluggish on hills.
windrush:
It was surprising the difference in performance between our Foden Haulmaster’s with the Gardner 201/ Fuller nine speed/ Foden worm and wheel diffs and our Sed Ak 400’s with the same engine/gearbox but with the Eaton back end. Those worm and wheel diffs must have absorbed a lot of power?
I recall the Foden in my avatar pic doing around 1600 rpm at 60 mph (Rolls 265Li) but the engine only revved at 1950 maximum the same as our Gardners so was a little sluggish on hills.
Pete.
You are probably right. Although Foden denied it and reckoned there was very little difference…
How many ‘old’ wagons were driven with a stick holding the throttle pedal down? They were flat out all day…
The older NA engines were not stressed like the turbo units, so were more capable of taking it I would say.
How many ‘old’ wagons were driven with a stick holding the throttle pedal down? They were flat out all day…
The older NA engines were not stressed like the turbo units, so were more capable of taking it I would say.
True, personally I would rather have a large capacity lightly stressed NA engine than a smaller one with a ‘snail’ bolted to it trying to get a quart out of a pint pot but then I am an old fashioned sod!
This talk of high revs doesn’t fit with my memories.
In Sed Ack 401 chassis with standard 8/9 speed Fuller and Rockwell axle mine was doing exactly 70mph @ 1100 RPM, don’t recall it ever getting anywhere near 1800 rpm such was the torque available that it would have been complete waste in all ways, without working it out i suspect @ 1800 rpm in top you’d be doing well over 100.
It could pootle along all day long between 800 and 1200 rpm without looking at the rev counter just going by sound alone, made driving an absolute pleasure that i haven’t found in any other lorry since then…except oddly enough the much dismissed (lacking kudos for the image crew) previous model Axor 430 which displayed similar low rev high torque capability.
How many ‘old’ wagons were driven with a stick holding the throttle pedal down? They were flat out all day…
The older NA engines were not stressed like the turbo units, so were more capable of taking it I would say.
True, personally I would rather have a large capacity lightly stressed NA engine than a smaller one with a ‘snail’ bolted to it trying to get a quart out of a pint pot but then I am an old fashioned sod!
Pete.
Well I must be an old fashioned sod too, As I agree with you, These young drivers we have today don’t know anything about NA Engines, Mind you Im not knocking them in any way, They drive motors today that’s well out of my league, All this modern stuff that we have is not for me, But its the way forward like everything else these days,Regards Larry.
Referring to tractor units, when Seddon Atkinson brought out the 401 there had already been a couple of years of International Harvester ownership producing IH sourced components like the D 358 engine in the 200 and the DT 466 in the 300. The first 401s abandoned the 400’s group hub reduction axle and used an IH made RA 57 single reduction diff with higher ratio gearing, for all except the limited-option Gardner powered vehicles. By this time we were a way into the Big Cam era with sufficient power and torque to pull the taller gearing. I recall taking an E320 401 up to Econocruise at Rugby to be instructed on how to fit their speed limiter. This was subsequently a popular fitment at the dealership, bringing the top speed down from something over 80 mph to the legal limit. Within a couple of years the inferior RA57 was dropped in favour of the single reduction fast-geared Rockwell axle which very quickly became the most popular rear axle of the time in British built lorries.
makes equally no sense to me. 
for the image crew) previous model Axor 430 which displayed similar low rev high torque capability.