ERF-Continental:
@Anorak…I think you are familiar with Unic’s M62S V8? 119x121mm, 10,766 litres…
I’m more interested in this one, as it seemed to follow the “short stroke, compact” route that AEC were pursuing. According to previous posts on this forum, it was launched in 1969:
That I need to verify better…when I find something I will no doubt input it, but don’t count on it 
The information I have mainly on Unic is with FIAT-engines and Unic was not that common in BeNeLux-
regions…and if, they had FIAT/Unic V85S under the hood, so the 135x130mm, 14,896 litres, 340hp.
[zb]
anorak:ERF-Continental:
@Anorak…I think you are familiar with Unic’s M62S V8? 119x121mm, 10,766 litres…I’m more interested in this one, as it seemed to follow the “short stroke, compact” route that AEC were pursuing. According to previous posts on this forum, it was launched in 1969:
0
Was it based on the same cylinder block as the M62S? Bearing in mind that it is a 15 litre engine, how do its package dimensions compare to the AEC V8?
You seem to be putting too much emphasis on that idea of bore stroke ‘ratio’ as opposed to actual measurements.There’s no way that you can compare a 15 litre V8 with a 130 mm stroke with a 13 litre with a 118 mm stroke measurement.Which is why you’ve ended up with something which at best only puts out around 250 hp at 2,400 rpm 
.
I think Stokes or anyone with any sense would have said along the lines yes great let’s chuck out the Rolls and ■■■■■■■ 6 cylinder options in the Crusader and the T45 and fit your idea instead.Less power and I wouldn’t like to be paying the fuel bills to run the thing and then Scammell will end up going the same way as AEC. 
The fact is there’s really very little relative advantages in going along the V8 route instead of the 6 cylinder one and it needs to be an exceptional V8 to make it worth while doing it and a 13 litre overall capacity limit with a 118 mm stroke won’t be anywhere close to the definition of ‘exceptional’.While if you’ve made a truck in which you can’t fit a decent 6 cylinder,or V8,then you’re going to need to design a better truck in which it will fit. 
As for me I’d agree with Bewick given the choice of your V8 or an 8 cylinder Gardner.
So, going back to the original question , how did the V8 compare performance wise only , to the V8 Scania of the time or even the 110 or the F88 ,i suppose there wouldnt have been too many swedes here in 68/`70 but they had started to arrive . The reliability and specification as already been discussed so just the performance side ,hill climbing etc , anyone know ■■? 
Good point and we’re back on the road…however there is an earlier question, why V-engines?
Was it merely to keep up with the rest…with or without results or was science involved?
ERF-Continental:
Good point and we’re back on the road…however there is an earlier question, why V-engines?Was it merely to keep up with the rest…with or without results or was science involved?
The idea of just adding more cylinders can be a cheaper way of getting a range of higher outputs from an existing engine design that has no scope for further enlargement than designing a totally new larger capacity engine with the same amount of cylinders.Hence all the Detroit multi cylinder variants and the Gardner 8 cylinder idea.It can also reduce stress levels by sharing the stresses across more cylinders.It can also cut down on the reciprocating masses of the moving engine componentry.
However using the V engine configuration cuts down on engine length and torsional crankshaft stresses/vibration issues of the inline design.Which as Gardner decided aren’t really a big issue with big slow revving truck diesels.While the same can arguably be said in the case of the reciprocating masses issue.Which is why there are some successful examples of 15 litre + 6 cylinder engines the ■■■■■■■ K series being an example in the day.
In this case if AEC was really looking for a decent V8,contrary to Anorak’s ideas,all AEC needed to do was design a V8 based on the bore and stroke of the 690.IE around 15 litres capacity.Which,with the exception of two strokes,is more or less the break point where a V8 becomes as/more viable than a 6 cylinder engine.Anything less than that it’s not really worth all the aggravation especially when torque drop becomes an ever greater issue as overall capacity and/or stroke measurement reduces.
As for the driving differences.To put it simply it’s a bit like trying to put a Cosworth DFV F1 V8 in a big heavy car and towing a heavy trailer with it.As opposed to using a Chevy 400 ci stroker for the job.IE the combination of too many cylinders,divided across a too small overall capacity,turns a 12 litre + engine into torqueless screamer that’s only really suited for hauling light weights.
Carryfast:
ERF-Continental:
Good point and we’re back on the road…however there is an earlier question, why V-engines?Was it merely to keep up with the rest…with or without results or was science involved?
The idea of just adding more cylinders can be a cheaper way of getting a range of higher outputs from an existing engine design that has no scope for further enlargement than designing a totally new larger capacity engine with the same amount of cylinders.Hence all the Detroit multi cylinder variants and the Gardner 8 cylinder idea.It can also reduce stress levels by sharing the stresses across more cylinders.It can also cut down on the reciprocating masses of the moving engine componentry.
However using the V engine configuration cuts down on engine length and torsional crankshaft stresses/vibration issues of the inline design.Which as Gardner decided aren’t really a big issue with big slow revving truck diesels.While the same can arguably be said in the case of the reciprocating masses issue.Which is why there are some successful examples of 15 litre + 6 cylinder engines the ■■■■■■■ K series being an example in the day.
In this case if AEC was really looking for a decent V8,contrary to Anorak’s ideas,all AEC needed to do was design a V8 based on the bore and stroke of the 690.IE around 15 litres capacity.Which,with the exception of two strokes,is more or less the break point where a V8 becomes as/more viable than a 6 cylinder engine.Anything less than that it’s not really worth all the aggravation especially when torque drop becomes an ever greater issue as overall capacity and/or stroke measurement reduces.
As for the driving differences.To put it simply it’s a bit like trying to put a Cosworth DFV F1 V8 in a big heavy car and towing a heavy trailer with it.As opposed to using a Chevy 400 ci stroker for the job.IE the combination of too many cylinders,divided across a too small overall capacity,turns a 12 litre + engine into torqueless screamer that’s only really suited for hauling light weights.
Why dont you just say i dont know because i never drove either vehicle … or not reply, simple
ERF-Continental:
Good point and we’re back on the road…however there is an earlier question, why V-engines?
Was it merely to keep up with the rest…with or without results or was science involved?
In most cases it’s to do with costs.
Compare component costs of a V configuration engine V’s the in line and the V wins every time, thus very popular with the accountants.
Look at the car industry, very few large capacity in line engines anymore, all to do with cost.
Crank has roughly half the mains so a heap less machining. The block is hugely smaller, again cheaper to make and to machine.
Big long blocks are quite a challenge to get even coolant flow, but an easier job for the short V block.
Multiple cylinder heads were common practice on an in line, usually only a single head on a V engine.
The shorter engine allows the cab designer far more flexibility. (An SAR KW with anything longer than an V8 GM or 903 ■■■■■■■ is a maintenance nightmare)
Everywhere you look, cost is the main factor.
ramone:
So, going back to the original question , how did the V8 compare performance wise only , to the V8 Scania of the time or even the 110 or the F88 ,i suppose there wouldnt have been too many swedes here in68/`70 but they had started to arrive . The reliability and specification as already been discussed so just the performance side ,hill climbing etc , anyone know ■■?
I don’t think that there are many out there that could have driven all, or any combination of AEC V8 / Scania 140 / Volvo F88, apart from the Commercial Motor testers of the time. Your lorry driver is a subjective person (nothing wrong with that) but he is perhaps not the best person to provide an objective judgement. The former AEC V8 drivers that gave me the most feedback were the Turners men that drove the prototype from 1966 to 1969 and they all agreed to a man that its performance was far better than anything else they had ever driven at the time. When I was driving the ■■■■■■■ V8 Dodge the thing that impressed me most for the first few days was the rev counter!! It was the first lorry I had ever seen with one fitted. Such trivialities can colour one’s judgement.
cargo:
ERF-Continental:
Good point and we’re back on the road…however there is an earlier question, why V-engines?
Was it merely to keep up with the rest…with or without results or was science involved?In most cases it’s to do with costs.
Compare component costs of a V configuration engine V’s the in line and the V wins every time, thus very popular with the accountants.
Look at the car industry, very few large capacity in line engines anymore, all to do with cost.
Crank has roughly half the mains so a heap less machining. The block is hugely smaller, again cheaper to make and to machine.
Big long blocks are quite a challenge to get even coolant flow, but an easier job for the short V block.
Multiple cylinder heads were common practice on an in line, usually only a single head on a V engine.
The shorter engine allows the cab designer far more flexibility. (An SAR KW with anything longer than an V8 GM or 903 ■■■■■■■ is a maintenance nightmare)
Everywhere you look, cost is the main factor.
I think that is an excellent point. Certainly at AEC in the 1950s the change from the 9.6 / 11.3 engines with separate cylinder blocks and crankcases to the monobloc 590 / 690 units was cost driven, to the extent that a considerable capital investment in new manufacturing machinery was made to reap future cost savings.
Just continuing the timeline of events in the 1960s, plus other snippets.
1962 Leyland / AEC merger valued the joint company at £410 million, today that would be £7.65 billion.
1963 Sir Henry Spurrier resigns as Chairman to be replaced by Sir William Black
1964 Donald Stokes appointed Group MD, Stanley Markland resigns.
1965 Group acquires a stake in Bristol Commercial Vehicles and Eastern Coach Works
1967 Group acquires Rover and Alvis
1967 Group acquires Aveling Barford
1968 Announced 500 Series engine to be made at Spurrier Works Leyland, potential output of 600 engines per week.
New V8 3.5 litre Rover engine announced
New AEC V8 engine announced
New Standard-Triumph 1.7 litre ohc engine announced
1868 Merger with British Motor Holdings agreed, new company to be called British Leyland Motor Corporation (BLMC)
Brief background notes:
Donald Stokes, son of the General Manager of Plymouth Corporation Transport, from an early age wanted to work for Leyland, joined Leyland as an Engineering Apprentice, wartime service in REME Technical branch, rising to the rank of Lt. Col. Returned to Leyland on his demob working in export sales department, various promotions to Sales Manager and then Sales Director.
Stanley Markland, not much known about his early career within Leyland, but by 1946 he was Leyland Chief Engineer. Later gained a reputation as a successful trouble shooter and a man who could get results.
So, just looking at the above there was one heck of a lot of stuff going on in the group for senior management to get to grips with, let alone the day-to-day running of the business. Add into the melting pot the implementation in 1965 of the very radical 1964 Construction & Use Regulations and all the implications of that, the most radical legislative changes in decades. Was the group management structure stretched beyond its capabilities and / or limitations? Just a line of thought worth pursuing?
gingerfold:
So, just looking at the above there was one heck of a lot of stuff going on in the group for senior management to get to grips with, let alone the day-to-day running of the business. Add into the melting pot the implementation in 1965 of the very radical 1964 Construction & Use Regulations and all the implications of that, the most radical legislative changes in decades. Was the group management structure stretched beyond its capabilities and / or limitations? Just a line of thought worth pursuing?
I don’t think that there was anything going on post 1965 which people of the calibre in question wouldn’t/shouldn’t have been capable of dealing with.The simple fact is getting it right was/is just a matter of choices based on known and foreseeable engineering requirements.In this case the difference,for example,being the AEC V8 powered Ergo cabbed Mandator v the Rolls/Detroit powered Crusader or Rolls and ■■■■■■■ powered Guy let alone the later Rolls and ■■■■■■■ powered T45 v the TL12 powered version.In all cases AEC’s design capabilities,at that point in time,being shown to have been overrated by many.Stokes,at least,was one of those who saw that,inconvenient for some,fact.
You can then add to that the backward demands of the domestic market in which many operators were still demanding Gardner powered products up to the end of the 1970’s sometimes even later.Which was a problem for which no engineering solution existed.
I refer the above poster to this table below, which would suggest to me that AEC had better engine designers than Rolls Royce.
gingerfold:
I refer the above poster to this table below, which would suggest to me that AEC had better engine designers than Rolls Royce.
The relevant bit being that the AEC V8 doesn’t seem to be in the comparison.A comparison itself which seems to be totally outdated in the engines chosen to compare at that point in time.IE a comparison of 1960’s thinking being applied going into the 1980’s.When as we all know those engines referred to were all made obsolete in the extreme by the move to 38t gross operation.
Having said that what it does seem to show is that 6 cylinders inline is the way to go in most cases regardless of the times.With the position of Gardner there being more an anomaly of the combination of it’s under stressed design and a domestic operating environment which at that time allowed it.Unlike what was about to take place a few years later.
Carryfast:
gingerfold:
I refer the above poster to this table below, which would suggest to me that AEC had better engine designers than Rolls Royce.The relevant bit being that the AEC V8 doesn’t seem to be in the comparison.A comparison itself which seems to be totally outdated in the engines chosen to compare at that point in time.IE a comparison of 1960’s thinking being applied going into the 1980’s.When as we all know those engines referred to were all made obsolete in the extreme by the move to 38t gross operation.
Having said that what it does seem to show is that 6 cylinders inline is the way to go in most cases regardless of the times.With the position of Gardner there being more an anomaly of the combination of it’s under stressed design and a domestic operating environment which at that time allowed it.Unlike what was about to take place a few years later.
Well it seems to me that the old designs were leading the way in the late 70s according to this chart Graham , at the end of the day its all down to how much it cost to run and downtime, I`m a bit surprised that the 250 ■■■■■■■ is up there after reading Bewicks comments on them being quite thirsty
ramone:
Well it seems to me that the old designs were leading the way in the late70s according to this chart Graham , at the end of the day its all down to how much it cost to run and downtime, I`m a bit surprised that the 250 ■■■■■■■ is up there after reading Bewicks comments on them being quite thirsty
That chart just shows running costs but not fuel consumption Ramone. The 250 ■■■■■■■ we had drank fuel like it was going out of fashion, which I suppose it now is!
Pete.
ramone:
Carryfast:
gingerfold:
I refer the above poster to this table below, which would suggest to me that AEC had better engine designers than Rolls Royce.The relevant bit being that the AEC V8 doesn’t seem to be in the comparison.A comparison itself which seems to be totally outdated in the engines chosen to compare at that point in time.IE a comparison of 1960’s thinking being applied going into the 1980’s.When as we all know those engines referred to were all made obsolete in the extreme by the move to 38t gross operation.
Having said that what it does seem to show is that 6 cylinders inline is the way to go in most cases regardless of the times.With the position of Gardner there being more an anomaly of the combination of it’s under stressed design and a domestic operating environment which at that time allowed it.Unlike what was about to take place a few years later.
Well it seems to me that the old designs were leading the way in the late
70s according to this chart Graham , at the end of the day its all down to how much it cost to run and downtime, I`m a bit surprised that the 250 ■■■■■■■ is up there after reading Bewicks comments on them being quite thirsty
At the end of the day it’s actually how many max weight miles it can run in a day/week/month/year ‘combined’ with how much fuel it needs to do it and how durable it is over the course of it’s working life.In which case it’s no surprise that the simple under stressed Gardner was at the top of a list which just selectively chose one of those criterea,in the form of maintenance costs,to base the comparison on.
Things would all look a lot different assuming that ‘combination’ of factors was the basis of the comparison and it had then included all the usual turbocharged bigger power options of the day.Especially if it had been carried out just a few years later under 38t gross operating conditions.
windrush:
ramone:
Well it seems to me that the old designs were leading the way in the late70s according to this chart Graham , at the end of the day its all down to how much it cost to run and downtime, I`m a bit surprised that the 250 ■■■■■■■ is up there after reading Bewicks comments on them being quite thirstyThat chart just shows running costs but not fuel consumption Ramone. The 250 ■■■■■■■ we had drank fuel like it was going out of fashion, which I suppose it now is!
Pete.
The early ■■■■■■■ (into this country) did gain a reputation as fuel guzzlers, but a robust engine nevertheless that gave little trouble in service. The chart, as you rightly comment, gives running costs without fuel factored into the sums. Back in those days at 32 tons gvw 8.00 mpg was the benchmark and anything betweeen 7.00 to 8.00 mpg was acceptable. Whilst fuel costs have always been important to a haulier (especially), they weren’t as significant then as they are today, Early 1970s DERV was about £0.30 per gallon (yes gallon) and drivers’ wages were the highest weekly running cost. Fuel prices only started to increase rapidly after the start of the 1973 Israeli / Arab war and when OPEC realised that it was a powerful organization.
