Author Topic: Four Cylinder Engine  (Read 888 times)

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Mike Farmer

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Four Cylinder Engine
« on: 28 March, 2023, 21:35:26 »
 :) :) :) :)

Greetings. I have spent a couple of hours today doing nothing and pccasionally letting my thoughts 'roam'. What I am about to say may have huge holes and not a grain of truth; however!

I am told that in the lateish 60's that BSA had developed a 4 cylinder across the frame engine/bike for the next racing season and that on the eve of the first races, the project was cancelled  and the whole of the BSA Racing was shut down.

Something in my mind tells me that, oddly, about 18 months later Honda produced their  "500 Four" a beautiful bike with a super smooth engine and , I believe relatively trouble free.

So my mind drifted to the question, is there a connection? Coincidence or chicanery? there is little doubt in my mind providing the BSA engine existed.

Mike  8) 8) 8)

Spaceman

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Re: Four Cylinder Engine
« Reply #1 on: 29 March, 2023, 07:56:51 »
I may be wrong but I don't remember Bert Hopwood saying anything about a 4-cylinder motorcycle in his book ("Whatever happened to the British motorcycle industry") - he, of course, was in involved in developing the 3-cyclinder BSA/Triumph engines.

The advantage of a 4-cylinder race engine is that you can spin it faster because the engine stroke and therefore max piston speed is less than an equivalent 2- or 3-cylinder engine - as a result, it is capable of producing more power because of the higher rev limit. However, you can only achieve this using an OHC engine and BSA/Triumph at the time were still wedded to OHV engines.

The Rocket 3 was the first super bike introduced in 1968 but, unfortunately, overshadowed a year later by the Honda CB750 Four. I've never ridden a Rocket 3 but I have ridden a CB750 and, like most of the 4-cyclinder Japanese bikes that followed, it has a super smooth, bullet proof engine that has been superbly engineered.

That said, I don't really need the smoothness of a 4-cylinder engine for road use - even the 3-cylinder engine in my modern Triumph is a bit too turbine-like for me at times and I rarely take it above 5k rpm. However, I think BSA/triumph got it right back in 1968 with a 3-cylinder engine but, where they fell well short in being able to compete with Honda, was by not developing a 3-cylinder OHC engine!

Mike Farmer

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Re: Four Cylinder Engine
« Reply #2 on: 29 March, 2023, 11:08:38 »
 :) :) :) :)

I am given to understand that there is a BSA racer with a 4 cyl engine in one of the museums.  Sammy Millers?????

Where they really fell short was not putting electric start on the completely new range of unit construction bikes. Certainly should have done so by 1966/7 models.

Mike 8) 8) 8) 8)

Spaceman

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Re: Four Cylinder Engine
« Reply #3 on: 29 March, 2023, 17:11:16 »
From what I can see, in the late 1960's, BSA and Triumph joined forces to enter tuned up Tridents in production races and went on to win the TT 750 production class from 1971 and 1975. One of these racing bikes ('Slippery Sam') was displayed at the National Motorcycle Museum but was destroyed in the 2003 fire.

ducati2242

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Re: Four Cylinder Engine
« Reply #4 on: 29 March, 2023, 21:30:26 »
Destroyed it was but then completely re-built . Think the rebuilt version is still there .
1956 bsa GS DB500
1968 mk1 Rocket 3
2006 ducati 999R .

Mike Farmer

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Re: Four Cylinder Engine
« Reply #5 on: 30 March, 2023, 09:29:59 »
 :) :) :) :)

Thanks for your replies. I have no actual knowledge of this but would like to know whether theres truth or no

Mike 8) 8) 8)

Pete Gill

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Re: Four Cylinder Engine
« Reply #6 on: 30 March, 2023, 13:45:47 »
I think a 4 cylinder quadrant version of the trident engine was built as a prototype but not further developed. It’s in the National motorcycle museum. Also I believe OHC version of the Triumph/BSA engines were prototyped but they didn’t go further as the power output was not significantly different from the pushrod engines. The 750cc triple OHV engine was a very powerful unit in its day.
My view is that BSA as a company were not really passionate about motorcycles as much as we like to think. They were all about turning a profit and repaying dividends to shareholders. They let the motorcycle business go as it was losing money.

johnr

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Re: Four Cylinder Engine
« Reply #7 on: 23 April, 2023, 23:54:24 »
the quadrant prototype is in the nmm in brum, its effectively a 750 tripple with an extra pot added but i think that by the time it was rushed together to counter the cb750 and impending z1, the writing was on the wall for nvt and the money ran out for development of new stuff like that.

scousebantam

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Re: Four Cylinder Engine
« Reply #8 on: 23 May, 2023, 12:46:26 »
In circa 1967 BSA moved to Umberslade and there was talk about a 4 cylinder. This passage was taken from Brad Jones's book
about the last days of BSA.
I am sure he wouldn't mind me showing the passage, I do recommend the book. 

Spaceman

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Re: Four Cylinder Engine
« Reply #9 on: 23 May, 2023, 14:40:52 »
I think the design team at Umberslade Hall looked at various concepts including a 500 cc four-cylinder engine but this was not the same as the 1000 cc Quadrant engine produced by Doug Hele at Triumph by essentially welding parts of 2 x Trident engines together in the best Allen Millyard tradition. It's not clear what the point of this exercise was!

AltcarBob

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Re: Four Cylinder Engine
« Reply #10 on: 27 May, 2023, 22:44:15 »
BSA could have designed a modern 4 cylinder engine but I doubt that BSA could have built it. You need precision and quality control  to build something like the CB750 not something that Small Heath was known for.
At the bottom of a very steep learning curve. More dumb questions to follow

BILL NELSON

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Re: Four Cylinder Engine
« Reply #11 on: 29 May, 2023, 10:30:35 »
BSA could have designed a modern 4 cylinder engine but I doubt that BSA could have built it. You need precision and quality control  to build something like the CB750 not something that Small Heath was known for.
You forget that BSA was much more than a manufacturer of motorcycles. BSA was one of Britain's major engineering groups and made a vast amount of the tooling for the wider engineering and precision engineering industry. BSA Tools had continued as a respected business until recently.
BSA was also a major supplier of components and castings to many other businesses.
Management shortcomings and failings are widely and correctly referred to, but most commentators forget the economic turbulence and expecially the politics associated with government policies. (I'll steer clear of politics and government policies as there is still no proper, comprehensive study of all the relevant factors many of us lived through and remember).
However, the involvement of Dennis Poore, ex 1950s racing driver and his political affiliations and contacts cannot be ignored.
He had become Chairman of Manganese Bronze Holdings, which made ships propellers and in 1960s bought Villiers. He then sold the propeller business and used the cash to start buying up motorcycle companies, starting with AMC, using Villiers, which had become a finance/investment company to do it. It could be argued that there was genuine poitical interest in Government to save the bike industry, but Poore was one of the early (but not the first) Financial Engineers, who focused on the money, rather than the engineering and certainly not the people. He sold off the non-bike parts of BSA & shut down the guns business very quickly and triggered union troubles (let's all blame the unions, or maybe not?) by sacking 67% of the workforce in one go.
The new owners of BSA (I stress, again, they did not just "buy the name") have gone on record as saying that BSAOC has been responsible for keeping the brand name, the brand values and the spirit of BSA alive, after the collapse of the company itself. Phil and Chris and I have met the people behind Classic Legends (parent company of BSA) and can confirm they are far more interested in BSA and Bikes than they are in money. Phil & I contributed to the initial design specification meeting for the new bike and it was us who came up with "The Bike BSA Would be Building if Production Had Continued".
We also met the Engine Designer - the range and extent of his work in racing and other branches of engine design make some of the media commentaries on the new BSA engine nothing short of ludicrous. Hey-ho, maybe the "Experts" should actually ask the man himself?
We also met Bal the actual Designer of the new BSA. A key element of the design was to build a platform which owners could adapt to suit themselves. Just like we used to do before the 1980s, when "originality" became the thing. Again, the media experts announced that the Scrambler shown at the NEC in December was a "soon to be announced new version".
Pardon my laughing, but the fact is that Bal and 2 of his colleagues built that bike in their spare time in 3 weeks using off-the-shelf components as a bit of fun and to show how adaptable his design is! Bal also supplied the Scrambler photo that appeared on the front of The Star.
BSA is alive and well, never really went away and has been kept in the eyes of decision makers by us all, the proud and friendly and happy Members of The BSA Owners' Club.

Mike Farmer

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Re: Four Cylinder Engine
« Reply #12 on: 29 May, 2023, 22:27:43 »
 :) :) :) :)

Hi Thank you for your very succinct and erudite (short) expose. It was/is of great interest for me. As you so rightly ponted out a lot of twaddle has been talked about most aspects of our new baby. Mia Culpa. Even tho no longer being able to ride I am still tempted. My two sons have both volunteered to complete the onerous task of riding it. Very unlikely. In the meantime I wish you all well and a safe summer.

Mike 8) 8) 8) 8)