115 replies to this topic

[Mite]

Understand the limitations of a 1600cc A-Series (having got David Vizard's book), yet what changes would have been necessary earlier during the A-Series engine's development for this displacement to be more of a production reality in place of the existing 1275cc A-Series? Would it have just been enough for the A-Series to group all its components / accessories including the pushrods on one side of the cylinder block or would further development changes have been needed earlier on for an A-Series to be able to achieve a displacement of 1600cc?

 

Failing that. Would a 1600cc displacement have been more likely if the A-Series was developed in the same way the O-Series was developed out of the B-Series, the O-Series originally being a clean-sheet design until cost constraints forced the company to carry over parts of the B-Series?

 

Have come across other ways the A-Series could have been developed during its production-run many of which never reached production for one reason or another, yet neither of the two development paths mentioned above have been explored.

Edited by Mite, 19 June 2018 - 12:25 AM.

[nicklouse]

earlier in the development. 

 

it did not really work like that as both the A and the B were based on the same original design.

 

the engine sizes were often created to fit current motor sport engine size rules and later to fit in with the tax breaks for company cars.

 

so really they would have had to have opted on a 1600 back then but i guess it would have needed to be a different casting to allow for casting tolerances and reliability.

 

and you just mentioned money there was not any.but yet there were quite a few development A series engines built but no were based on larger engine size but were on efficiency and weight.

[mab01uk]

The A-Series did well to eventually achieve 1275cc displacement in production bearing in mind it originally started life in 1952 as 803cc......

 

Some links below which may be of interest.

 

A-Series engine: a hard act to follow:-

https://www.aronline...gines-a-series/

 

The OHC A-Series and 9X Engines:-

http://www.theminifo...and-9x-engines/

 

A-Series - The First 60 Years:-

http://www.theminifo...first-60-years/

Edited by mab01uk, 19 June 2018 - 06:26 AM.

[Spider]

Just keep in mind that the A Series was originally designed as an 803 cc engine, but if I recall, it was done in a way to take it up to the 1 litre class with few changes. So, with that in mind, they already stretched it out to 1275, albeit, with a redesign of the A Series Engine as it first stood.

 

So taking them out further is only stretching an elastic band that's already been stretch a fair way. Taking them to circa 1600 CC is doublig their original size!! Not many engines about that can be taken so far.

 

I would say, as covered in mab01uk's post ^, the next step would have been to redevelop the cylinder head and Incorporate an OHC, with a further development to take that to DOC.

 

I was only chatting about these engines this morning, if I recall, the development of the A+ cost a claimed 35 million pounds and this was over the period 1977 - 1979 !! Serious money. We had a whole car designed and put in to production locally around that time for about the same money, and that included a serious upgrade of a current engine range, so exactly what was done for 35 million pounds I really can't see and IMO, the A+ engines aren't that good, in fact, the series just prior to the A+ were streets ahead of them in many respects.

[unburntfuelinthemorning]

Just keep in mind that the A Series was originally designed as an 803 cc engine, but if I recall, it was done in a way to take it up to the 1 litre class with few changes. So, with that in mind, they already stretched it out to 1275, albeit, with a redesign of the A Series Engine as it first stood.

 

So taking them out further is only stretching an elastic band that's already been stretch a fair way. Taking them to circa 1600 CC is doublig their original size!! Not many engines about that can be taken so far.

 

I would say, as covered in mab01uk's post ^, the next step would have been to redevelop the cylinder head and Incorporate an OHC, with a further development to take that to DOC.

 

I was only chatting about these engines this morning, if I recall, the development of the A+ cost a claimed 35 million pounds and this was over the period 1977 - 1979 !! Serious money. We had a whole car designed and put in to production locally around that time for about the same money, and that included a serious upgrade of a current engine range, so exactly what was done for 35 million pounds I really can't see and IMO, the A+ engines aren't that good, in fact, the series just prior to the A+ were streets ahead of them in many respects.

In what ways were the series just prior to the A+ engines streets ahead?  I was always under the impression the A+ was an improvement e.g. block stiffness, improvements to the crankshaft fillet radii...

[Ethel]

A Series 803 - 1275cc

B Series 1200 - 1798cc

 

Would even BL have developed a 3rd pushrod engine of around 1600cc's?

 

They stuck a turbo on the A for more power in the Metro.

[dotmatrix]

if budgets weren't cut for the metro development we would now have (or have had) OHC alu heads for our A-series engines.

[Cooperman]

The A series engine was designed when the cost of road tax in the UK was based on a very strange HP calculation method. For dome strange reason the bore to stroke ratio was a big factor and a small-bore long-stroke engine attracted lower tax than a similar capacity engine with a shorter stroke.
Unfortunately BMC failed to design a nee engine range when other manufacturers did. For example, Ford introduced the new 997 engine in their Anglia in 1959 and it was an over-square unit of modern 8-port design.
BMC stuck with the old A, B and C Series long stroke engines which soon reached the practical limits of further development whilst Ford went on to develop larger versions of their same basic unit including twin-cam versions.
Realistically a new engine range was needed for BMC in the late 1950's but it didn't happen.
One can only imagine an MGB with a 2-litre OHC alloy engine.
Even more odd is that when Triumph and Rover became part of BMC no attempt was made to rationalise the range of power units and take the most modern ones as the way forward. The Dolomite engines were quite good.
It is a real shame that BMC failed with their engine development and why they designed a good OHC engine for the Maxi but went no further with it does seem strange.

[Spider]

 

In what ways were the series just prior to the A+ engines streets ahead?  I was always under the impression the A+ was an improvement e.g. block stiffness, improvements to the crankshaft fillet radii...

 

 

I'll agree that the A+ Rods are better than those before and the Cranks too. Like you, when I read up on them in the first instance, I thought they sounded great on paper and have tried loads of them since, but, much as I didn't want to admit to it for a long while, they fall well short. The blocks I find extremely disappointing for all the hype of them. Setting aside the really bad machining from the factory, I'm no metallurgist, however, the grade of cast Iron in them is odd and has a big grain structure, it would appear that following casting (with seeming what was swept up off the floor) they didn't undergo proper post casting heat treatment / stress relieving. No doubt, you would also be aware, that loads of early ones were porous and this only shows up this poor casting methods. The ribbing etc on the block seriously does nothing - next time you have one in bits, have a real good look at where it is and you'll see what I'm saying here. Well, I guess the ribbing does one thing - it makes them quite distinguishable from earlier blocks.

 

I've found the 1275 blocks made from around 1976 to 1979 way better every time. The cast iron itself machines nicer and gets a much more desirable finish for the job in hand. The factory machining accuracy was better and need much fewer corrections. One would think this would have continued with the A+ and I can't say why it didn't, but every A+ Block I've come across needs loads of machining corrections done.

 

Even the earliest 1275's were better than the A+ Blocks.

 

And, coming back to the money that was spent on it - I just cannot see where it was spent, I can see about 1, maybe 2 millions for the R&D, tooling etc, but that's it. The cranks, while better, weren't pioneered by Leyland, the Rods, while an improvement, also weren't 'revolutionary' and the block, well, what did they really do there? The Camshaft Profiles used in most of them were still the same profile dating back to the 60's, though some had revised 'nominal' phasing to the crank but that was only done with the sprockets.

 

For 35 millions, they could have come up with a completely new, modern (for the era) engine.

[Spider]

Realistically a new engine range was needed for BMC in the late 1950's but it didn't happen.
One can only imagine an MGB with a 2-litre OHC alloy engine.

 

As one example of their engine range - YES.

 

I believe they stuck to many of their antiquated designs as while they were happy to fund R & D for more modern engines, and they would have mass produced them but they wouldn't modernise the machinery on their production line (Transfer machines) to be able to machine these newer engine designs.

 

There's some good info on these wonderful for their time machines here;-

 

http://www.austinmem...-128/index.html

[grizzler73]

It was only ever going to go one way with the lack of investment and unimaginative management that blighted the UK motor industry in the period. We can talk about developing the A series till the cows come home, but it needed replacing in the early 70's. Look at the engines Honda produced in that time, they just don't compare.

[nicklouse]

It was only ever going to go one way with the lack of investment and unimaginative management that blighted the UK motor industry in the period. We can talk about developing the A series till the cows come home, but it needed replacing in the early 70's. Look at the engines Honda produced in that time, they just don't compare.

Nissan did the development work back in the late 60s and look at what it became

[grizzler73]

Exactly Nick. It's a often trotted out story that the unions killed the car industry, but really they were protesting because they could see what was happening. Now the only big car factories in the UK are from overseas companies. You reap what you sow...

[Spider]

I don't disagree here grizzler, however that the A Series did last so long and in many ways kept pace (in things like emissions and fuel figures etc) is a bit of a testimate as to how good the original design was, but yes, by the 70's, compared to the opposition, it really was an old, outdated engine and certainly should have been pulled from production by the mid 70's.

[r3k1355]

 

It was only ever going to go one way with the lack of investment and unimaginative management that blighted the UK motor industry in the period. We can talk about developing the A series till the cows come home, but it needed replacing in the early 70's. Look at the engines Honda produced in that time, they just don't compare.

Nissan did the development work back in the late 60s and look at what it became

 

 

Yes if you want to look at A-series development then look at what Nissan did with it.

 

They licensed the design and promptly set about sorting things out, knocking out several different engine lines, evolution ended in a twin cam turbo engine.

It's not like we didn't have the exact same opportunities to do similar work, yet the best they could manage was the A+ engine in the 80's.

 

Comparing the two it's pathetic really.

Edited by r3k1355, 19 June 2018 - 10:19 AM.