Jump to content


Photo
- - - - -

A Series Vs. B Series


  • Please log in to reply
35 replies to this topic

#1 mini_pooper

mini_pooper

    Stage One Kit Fitted

  • TMF+ Member
  • PipPipPip
  • 63 posts
  • Location: Cleethorpes

Posted 08 May 2018 - 11:42 AM

Hi all,

 

I spent some time last night pondering how the A Series and B Series BMC engines are very similar in appearance, and thought, for a bit of fun, I would post a topic here where folks can discuss the ways in which they are similar and how they differ.

 

I had a '64 MGB for a few years (1800cc, 3 bearing, not the later 5 bearing) and it gave me a lot of respect for the B Series engine: smooth, torquey and great fun. Now I have a Mini (998) and can feel a lot of the same characteristics that the B Series had.

 

So, without going into how you can or can't fit a B Series to a Mini (understeer and shoehorning deluxe!!):

 

- How similar are these engines?

- What parts do they share both externally and internally?

- Did they have the same design team?

- Was the B Series an evolution of the A Series?

- In what ways/areas is one superior to the other?

- Any other fun facts about the 2 engines

 

Again, just for a bit of fun and education!!  :D


Edited by mini_pooper, 08 May 2018 - 11:44 AM.


#2 r3k1355

r3k1355

    Speeding Along Now

  • Members
  • PipPipPipPipPip
  • 415 posts
  • Local Club: East Anglia

Posted 08 May 2018 - 02:17 PM

Well wasn't the A-series a new design whereas the B-series was more an evolution of an OHV engine??

 

One thing I guess both share is that they stuck around in production for quite a long time, probably longer than they should have.



#3 mini_pooper

mini_pooper

    Stage One Kit Fitted

  • TMF+ Member
  • PipPipPip
  • 63 posts
  • Location: Cleethorpes

Posted 08 May 2018 - 04:35 PM

I don't know which was developed when, but the A series certainly has its roots in the 50s (or was it 40s the first Morris Minor was launched?

The B Series was very similar in construction to the A series in that it had pushrods and tappets (with the cam buried deep in the engine like the A series). At first glance, the British series would appear to be nothing more than an over dimensioned A series built to cope with larger vehicles... :)

Edited by mini_pooper, 08 May 2018 - 04:36 PM.


#4 DeadSquare

DeadSquare

    Stage One Kit Fitted

  • Noobies
  • PipPipPip
  • 62 posts
  • Location: Herefordshire

Posted 08 May 2018 - 04:59 PM

When I wanted to "hot-up" a Morris Minor in the late 50's, Alick Dick of Standard Triumph told me that the A series started life before the war with a sporty single overhead cam.  At some point it became a side-valve engine, hence the two tappet chest covers, before morphing into the 803cc overhead valve engine.

 

I don't know when the 1200cc B series engine went into production.



#5 Albino_Hedgehog

Albino_Hedgehog

    Speeding Along Now

  • Traders
  • PipPipPipPipPip
  • 305 posts
  • Location: Rubery
  • Local Club: Solihull Mini Classic Club

Posted 08 May 2018 - 05:57 PM

Just as an interesting fact...

The Mini's in the Italian Job, were fitted with the B' Series engine, as they were worried the the A' Series wouldn't be powerful enough to make the roof jumps, and climb the stairs!

Edited by Albino_Hedgehog, 08 May 2018 - 05:59 PM.


#6 mini_pooper

mini_pooper

    Stage One Kit Fitted

  • TMF+ Member
  • PipPipPip
  • 63 posts
  • Location: Cleethorpes

Posted 08 May 2018 - 05:59 PM

Heard rumors of that, lucky they didn't just go nose down into the street below ;)

#7 DeadSquare

DeadSquare

    Stage One Kit Fitted

  • Noobies
  • PipPipPip
  • 62 posts
  • Location: Herefordshire

Posted 08 May 2018 - 07:11 PM

Just as an interesting fact...

The Mini's in the Italian Job, were fitted with the B' Series engine, as they were worried the the A' Series wouldn't be powerful enough to make the roof jumps, and climb the stairs!

 

 

Any idea what gearbox they used?



#8 mini_pooper

mini_pooper

    Stage One Kit Fitted

  • TMF+ Member
  • PipPipPip
  • 63 posts
  • Location: Cleethorpes

Posted 08 May 2018 - 07:35 PM

Just as an interesting fact...
The Mini's in the Italian Job, were fitted with the B' Series engine, as they were worried the the A' Series wouldn't be powerful enough to make the roof jumps, and climb the stairs!

 
 
Any idea what gearbox they used?

Maybe they just ran a chain directly from the Crank to the driveshafts! That would make for an interesting ride! :)

#9 DeadSquare

DeadSquare

    Stage One Kit Fitted

  • Noobies
  • PipPipPip
  • 62 posts
  • Location: Herefordshire

Posted 08 May 2018 - 07:56 PM

 

 

Just as an interesting fact...
The Mini's in the Italian Job, were fitted with the B' Series engine, as they were worried the the A' Series wouldn't be powerful enough to make the roof jumps, and climb the stairs!

 
 
Any idea what gearbox they used?

Maybe they just ran a chain directly from the Crank to the driveshafts! That would make for an interesting ride! :)

 

 

You'd need a pretty steep hill to roll it down to get it started, Lol


Edited by DeadSquare, 08 May 2018 - 07:58 PM.


#10 Moke Spider

Moke Spider

    Crazy About Mini's

  • TMF Team
  • PipPipPipPipPipPipPipPipPipPip
  • 7,140 posts
  • Location: NSW

Posted 08 May 2018 - 08:45 PM

There's a little on this in the book 'The A-Series Engine - the first 60 years'

 

If I recall, some design frame work was very roughly laid down for what requirements a family of Engines would need to cover and these were the A, B and C Series.

 

Initial work started on the A Series, but was put on hold to fully develop the B Series as a new car was coming that needed it, then they returned back to the A Series.

 

Again, this is a recollection from some time back when I read the book.

 

There are a few parts that these engines share too ;D



#11 mini_pooper

mini_pooper

    Stage One Kit Fitted

  • TMF+ Member
  • PipPipPip
  • 63 posts
  • Location: Cleethorpes

Posted 08 May 2018 - 08:48 PM

So that begs the question, what and where is the C series? :)

I know MG produced the MGC, in effect an MGB with a straight six engine, was this the C engine, or did the C series never make it past the drawing board?

#12 mini_pooper

mini_pooper

    Stage One Kit Fitted

  • TMF+ Member
  • PipPipPip
  • 63 posts
  • Location: Cleethorpes

Posted 08 May 2018 - 08:58 PM

Quick search, the C series was in fact the straight six as used in the Austin Healey 3000. From Wikipedia:

"The BMC C-Series was a straight-6 automobile engine produced from 1954 to 1971. Unlike the Austin-designed A-Series and B-Series engines, it came from the Morris Engines drawing office in Coventry and therefore differed significantly in its layout and design from the two other designs which were closely related. Displacement was 2.6 to 2.9 L with an undersquare stroke of 88.9 mm, bored out to increase capacity."

Breif info on the A series:
"Austin Motor Company's small straight-4 automobile engine, the A-Series, is one of the most common in the world. Launched in 1951 with the Austin A30, production lasted until 2000 in the Mini. It used a cast-iron block and cylinder head, and a steel crankshaft with 3 main bearings. The camshaft ran in the cylinder block, driven by a single-row chain for most applications, and with tappets sliding in the block, accessible through pressed steel side covers for most applications, and with overhead valves operated through rockers. The cylinder head for the overhead-valve version of the A-Series engine was designed by Harry Weslake a cylinder head specialist famed for his involvement in SS (Jaguar) engines and several F1 title winning engines. Although a 'clean sheet' design the A-Series owed much to established Austin engine design practise, resembling in general design (including the Weslake head) and overall appearance a scaled-down version of the 1200cc overhead-valve engine first seen in the Austin A40 Devon which would form the basis of the later B-Series engine."

And B series:
"The precursor of the "B" series engine was a 1200 cc Overhead Valve (OHV) engine which was used in the 1947-1952 Austin A40 Devon, and, in slightly modified form, in the 1953 Austin A40 Somerset. This engine had the same basic dimensions as one of Austin's pre-war sidevalve engines but to an all-new OHV design which had many features copied from the Chevrolet 235 straight-six engine used on military trucks that the Austin works had overhauled during the Second World War. These features included the valve gear and especially the siamesed cylinder head ports. Austin realised that eventually they would need an engine that could power many of its forthcoming medium-sized cars, and this would require an engine of at least 1500 cc capacity. Since the A40 Devon engine could not have its capacity enlarged, a new engine needed to be designed and built.

The design of this new engine commenced around January 1952, and was designated as the "B" series."

Surprisingly, the B series is also listed as a straight 6 configuration, as well as the well known inline 4...

Edited by mini_pooper, 08 May 2018 - 09:00 PM.


#13 mab01uk

mab01uk

    Crazy About Mini's

  • Members
  • PipPipPipPipPipPipPipPipPipPip
  • 8,425 posts
  • Local Club: Mini Cooper Register

Posted 08 May 2018 - 10:30 PM

 

Just as an interesting fact...

The Mini's in the Italian Job, were fitted with the B' Series engine, as they were worried the the A' Series wouldn't be powerful enough to make the roof jumps, and climb the stairs!

 

 

Any idea what gearbox they used?

 

 

They would have used the Issigonis designed Austin/Morris 1800 (Landcrab) B-Series engine and gearbox which is basically a big Mini with transverse engine and gearbox in the sump like a Mini (plus Hydrolastic suspension)........

BMC 1800 development story

https://www.aronline...elopment-story/

 

 

AW7JrGM.jpg

 

nmygQ1d.jpg

 

LCh5fFL.jpg

 

 

 

There was also a fwd transverse E-Series straight six engine and gearbox for the 2200cc versions shown below in the Wolseley Six.....

 

oovn943.jpg


Edited by mab01uk, 08 May 2018 - 10:39 PM.


#14 DeadSquare

DeadSquare

    Stage One Kit Fitted

  • Noobies
  • PipPipPip
  • 62 posts
  • Location: Herefordshire

Posted 08 May 2018 - 11:04 PM

Would an 1800 engine and box fit in a mini subframe?

 

It was such a famous film, so why wasn't a conversion like that copied?   Think of Starwars figures, but for real boy racers boasting in the pub about their 1800cc mini, to some poor sod who only had 1320cc.



#15 Moke Spider

Moke Spider

    Crazy About Mini's

  • TMF Team
  • PipPipPipPipPipPipPipPipPipPip
  • 7,140 posts
  • Location: NSW

Posted 08 May 2018 - 11:27 PM

I'm pretty sure that's a 'tale' that they had bigger engines (like 1800's B Series).

 

I can't see them fitting in any case.

 

There's a book written on the Movie by someone who was involved in that making of it.






0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users

Mini Spares