BritBike Forum logo
BritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorThe Bonneville ShopBritBike Sponsor
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
ShoutChat Box
Comment Guidelines: Do post respectful and insightful comments.
Buy BritBike staff a coffee
Buy BritBike's staff a coffeeStill here since 1996 serving BritBike enthusiasts..
Search eBay for motorcycle parts in following countries
Australia, Canada, France, Holland, Italy, United Kingdom, USA
Random Gallery photo
Member Spotlight
63SuperRocket
63SuperRocket
Portland, ME
Posts: 68
Joined: September 2006
Show All Member Profiles 
Newest Members
Okiewan, B1KAR, Colin Peters, Richard77, Jon law
10908 Registered Users
Top Posters(30 Days)
franko 94
quinten 63
Popular Topics(Views)
1,050,311 mail-order LSR
a word from..
Forum Statistics
Forums34
Topics68,047
Posts682,956
Members10,907
Most Online14,755
May 5th, 2019
Who's Online Now
76 registered members (Alex Lynch), 555 guests, and 1,055 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Page 1 of 9 1 2 3 4 5 6 7 8 9
The what if A65 67hp challenge. #782021 08/20/19 9:07 am
Joined: Apr 2005
Posts: 2,559
Mark Parker Online Content OP
BritBike Forum member
OP Online Content
BritBike Forum member
Joined: Apr 2005
Posts: 2,559
67hp is what Honda claimed for their newly introduced CB750 OHC 4. It's quite possible at some stage Honda actually achieved that power on their dyno. Rear wheel dyno graphs of CB750s sold to the public proved to be shy of that output even when converting for the losses through the drive train. One CB750 tested in the US delivered 54rwhp @ 8,000rpm indicating around 61.5hp at the crankshaft.

What interests me is the fact that the BSA factory chose not to machine A65 inlet ports to the actual design drawing, ever, and when Umbeslade Hall technicians actually machined the inlet ports to the design drawings their motor made 8hp more on their dyno than production line units. This was an oil in frame photo shoot Firebird built in 1970. Not only was the engine more powerful it was also more responsive. The only difference was the machining of the cylinder head.

I'm curious what the result would be to machining the A65 inlet ports to one of the most efficient two valve port shapes known today. To do this I've enlarged the port slightly to 32mm and used a 42mm inlet valve from MAP Cycles. I'll also use slightly O/Size exhaust valves as well, though its probably unnecessary. So the head is ported and on my somewhat home made flow bench is indicating an excellent gain in flow 160cfm @ 28"W @.385"of lift compared to the factory heads 109cfm.

Fitting a round-slide carb restricts flow especially at 30-32mm bore. A 32mm Mikuni with long bellmouth reduced flow to 135.2cfm, with the bellmouth removed it was better at 139.17cfm, blending the carb intake enabled 145.5cfm.

Using Wallace Racing's on line hp calculator which bases its figures on intake port flow a 40cubic inch twin flowing 109cfm can produce 52hp at the crank (similar to BSAs claimed output) or 45.7rwhp approx. though like the XS650 Yamaha stock A65s are usually around 43-44rwhp. Calculating for 145cfm gives a estimate of 69hp at the crank, if it could achieve that it would translate to about 60.72rwhp.

So I'm interested to see if an otherwise stock A65 fitted with this head and 32mm carbs could equal or better the CB750s hp claim.

The modified carb:

[Linked Image from i.postimg.cc]

The new port shape:

[Linked Image from i.postimg.cc]

Not the actual head but one just like it.

[Linked Image from i.postimg.cc]

[Linked Image from i.postimg.cc]


mark
Support Your #1 BritBike Forum!

Check out British motorcycles for sale:
British Motorcycles on e-Bay UK
British motorcycles on e-Bay North America
Re: The what if A65 67hp challenge. [Re: Mark Parker] #782029 08/20/19 12:08 pm
Joined: May 2013
Posts: 5,937
Allan Gill Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: May 2013
Posts: 5,937
is this a round port Mark or have you filled the port floor?


beerchug
Re: The what if A65 67hp challenge. [Re: Mark Parker] #782030 08/20/19 12:16 pm
Joined: Apr 2005
Posts: 2,559
Mark Parker Online Content OP
BritBike Forum member
OP Online Content
BritBike Forum member
Joined: Apr 2005
Posts: 2,559
Oval port with filled floor.


mark
Re: The what if A65 67hp challenge. [Re: Mark Parker] #782104 08/21/19 4:16 am
Joined: Oct 2008
Posts: 5,741
DavidP Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Oct 2008
Posts: 5,741
And if BSA had actually done this to every production model they would have had to charge how much for each bike? They had enough trouble selling them at the price they charged.
Looks like a fun project though.


Stepping on others doesn't make you stand tall.

71 A65L "Zelda"
92 BMW K100rs "Gustav"
72 T120V cafe project "Mr. Jim"
72 T150V "Wotan"
Re: The what if A65 67hp challenge. [Re: Mark Parker] #782120 08/21/19 10:57 am
Joined: Aug 2014
Posts: 301
John Goodwin Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Aug 2014
Posts: 301
I'm really interested in hearing how it develops. I've been stopped by back and shoulder issues getting out into the shed and need some motivation. Mark has posted so much interesting information here and love his builds


Current: 2 x 1966 A65S, 1 x 1967 A65SA, 1 x 69/70? A65LA space Y, 1 X D14/4 & 1 x B175
Past: 4 x 1976 T160V, 1 74/5 T150V, 83 model GSX 750 ESD, Z650, Katana 1100(Bathurst Model), 79 T140V, 70's TR6, 2 x 1971 BSA 250 Gold Stars, 50's 350 Goldie, A65 Spitfire semi basket case, 1965/6? A65 LC, Tiger 21 350 & a D14/4 Bantam, 175 Bridgestone Twin with Zimmerman discs!
Re: The what if A65 67hp challenge. [Re: DavidP] #782125 08/21/19 11:57 am
Joined: May 2013
Posts: 5,937
Allan Gill Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: May 2013
Posts: 5,937
Originally Posted by DavidP
And if BSA had actually done this to every production model they would have had to charge how much for each bike? They had enough trouble selling them at the price they charged.
Looks like a fun project though.


Costs just as much to make something properly as it does it make something incorrect.

Be interested to know what the difference in the blueprint head and the other heads. theres 2 casting/part numbers for the OIF 2 carbs heads, a few suttle differences between them, but never measured the ports..... too late now as both of them are modified.


beerchug
Re: The what if A65 67hp challenge. [Re: Mark Parker] #782134 08/21/19 1:21 pm
Joined: Apr 2005
Posts: 2,559
Mark Parker Online Content OP
BritBike Forum member
OP Online Content
BritBike Forum member
Joined: Apr 2005
Posts: 2,559
It's not particularly hard to do the ports by hand. BSA could have done the ports at least to how they were designed rather than short cutting at the factory, it may have been saving them a little money and keep the A65 on parity with the Triumph twin which they also owned. In 1970 they knew the difference between the heads but didn't rectify the production, they could have had 8 more hp in 1971. In their day these bikes were among the fastest most powerful on the road, but they were about to be displaced, or by 1971 they were being displaced by the 750s and the power bikes from Japan.

It was hardly a time to throw away easy hp in what was a full-scale hp race. You can see this when the mighty Z1 Kawasaki turned up, it was called the King. It was developed as a 750 but Honda released the CB750 4, getting the jump. Kawasaki held off releasing their bike till they increased the displacement to 903cc the reason they did that was to sell bikes, they understood the power of power. Honda claimed 67hp Kawasaki trounced it with 82hp and 54.2ftlb, though it was heavy at 542lb. For perspective my 883cc A65 weighs around 360lb and produces 97hp and 71ftlb it also has a very wide power spread. It uses a bigger version of the oval port above, so I'm interested to see how that translates onto an otherwise stock engine.

BSA already knew how to fix all the problems with the A65, roller mains both sides would have reversed market resistance, 71 or earlier they had excellent steel capped rods, high volume oil pumps and they had the A70 showing great potential. But they sank money and effort into things like the Ariel 3. And also the 350s that were a good idea though eventually scrapped because of a shot to the foot.

The 350 was a missed opportunity, they could not get good power from it because the head design was poor, DH had made an error, easy to rectify with a new casting, but management told him no. So 34hp was the best they could ever get. The 350 Honda was already in the market with similar power, the BSA 350 could and should have made 45+hp, and it would have been a winner, it could then be more expensive than the Honda because it gave more, it had the advantage with a state of the art frame and running gear already. A company like Kawasaki would have made sure they had what they needed to get the power necessary. So rather than spend massive effort and money fruitlessly down these paths, BSA could have done three things, fixed the A65 engine completely, and at the same time, because its basically the same thing, developed the A70And the third, built at least a limited number of Rob North style Rocket threes, the frames were state of the art and exotic, cheaper to manufacture than the std frames. The threes also work extremely well at 850cc if they wanted to respond to the Z1 and Ducati's SS750 when they came along.


mark
Re: The what if A65 67hp challenge. [Re: Mark Parker] #782136 08/21/19 1:24 pm
Joined: Apr 2005
Posts: 2,559
Mark Parker Online Content OP
BritBike Forum member
OP Online Content
BritBike Forum member
Joined: Apr 2005
Posts: 2,559
Hey Allan, they changed the angle of the exhaust ports in 71 from what I've read. The '71 inlet ports are a bit different, but they are not good.


mark
Re: The what if A65 67hp challenge. [Re: Mark Parker] #782143 08/21/19 3:20 pm
Joined: Jan 2004
Posts: 4,255
D
DMadigan Online Content
BritBike Forum member
Online Content
BritBike Forum member
D
Joined: Jan 2004
Posts: 4,255
Hopwood in his book states the attitude of the Managing Director that BSA and Triumph machinery must be equally prepared so it was unlikely they would have made the improvement to the A65. When Dan Macias visited the Triumph factory he saw they were finishing the Triumph twin ports on a drill press. Doug Hele told him not to mention it because the operator had been doing it that way for many years.
By May 1971 BSA was looking at a loss of 1m GBP so was hardly in the position to make any changes to the design.
I think the A70 was the only one with steel capped rods but not sure.
The 350 was a disaster because it was "designed" by Turner (who checked valve springs by stepping on them with his heel). Two broken crankshafts and one valve gear failure in 1500 miles. The cutaway picture of the engine shows the characteristic Turner sharp angle between the port and valve. Also, by '71 you think they would have figured out it was a bad idea to put the output sprocket between the clutch and gearbox.

Re: The what if A65 67hp challenge. [Re: Mark Parker] #782151 08/21/19 4:18 pm
Joined: May 2013
Posts: 5,937
Allan Gill Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: May 2013
Posts: 5,937
I hear you Mark, there was little stopping them making a full production model of the A70, I think they made more Lightnings than Thunderbolts from 71 (sure seems that way as theyres loads of Lightnings and L stamped cases around compared to the T's) 850cc would have been a good step forward on the Mk2 Rocket 3..... Still such as life.


beerchug
Re: The what if A65 67hp challenge. [Re: Mark Parker] #782180 08/21/19 10:38 pm
Joined: Jan 2014
Posts: 414
N
NickL Offline
BritBike Forum member
Offline
BritBike Forum member
N
Joined: Jan 2014
Posts: 414
A massive slice of their market was the 'states.
It would have been more of a benefit to make the a65 more reliable and long lived than to uprate it's horsepower.
The average bloke who bought a bike wasn'r racing it, he was riding it once a week and poorly maintaining it.
His mates with triumphs could get away with not changing oil etc so he would do the same...........the beezer went bang.
They should have shut down in 1963 and moved production to the far east, that way they would have had local access to
a massive market and government funded factories/development. Competing with japan's zero interest rate for business at
that time was impossible, they could product dump anywhere in the western world with government backing, and they did.
Beezer was nothing compared to the yankee electronics industry they devastated.
The management at beezer were just selling it all off and getting out, they didn't want to make motorbikes, they wanted to
make money. Pi$$ing about modifying cylinder heads on an out of date engine that's been in production for 10+ years
is the sort of thing that makes firms go broke.
I understand the nostalgia and i love the old crates as well, but politics and economics etc. get in the way.

Re: The what if A65 67hp challenge. [Re: Mark Parker] #782184 08/21/19 11:54 pm
Joined: Oct 2012
Posts: 4,680
Hillbilly bike Online Content
BritBike Forum member
Online Content
BritBike Forum member
Joined: Oct 2012
Posts: 4,680
How long will a 67 HP 650 BSA engine last at high out put levels? .......Mark's project is interesting...let's see how it goes..... My 650 Triumph land speed racer is the only comphrensive dyno info I've seen on a Brit 650...It's like a T120 engine with a bit more cam and compression , 34mm carbs and raised intake port head. On a Superflow dyno, not the more optimistic Dynojet, it made 55 rwhp @ 7100 rpm and 46 ft lbs torque @5100 rpm. later on I moved the cam timing and the bike went a few MPH faster so maybe 58 rwhp at best...So maybe 65 hp at the crank?
Can a BSA make more power than one of Turner's turds? grin


79 T140D, 96 900M Ducati ....On a bike you can out run the demons..
Re: The what if A65 67hp challenge. [Re: Mark Parker] #782192 08/22/19 1:53 am
Joined: Apr 2005
Posts: 2,559
Mark Parker Online Content OP
BritBike Forum member
OP Online Content
BritBike Forum member
Joined: Apr 2005
Posts: 2,559
I have a half done '70 firebird in the shed with roller conversion bottom end, I'm just curious. If it got anything around 50 or more at the wheel it would be pretty cool, but you don't know what is actually possible without trying. Don't like the idea of the 360degree crank and the vibes but it would be interesting and give me motivation to build the Firebird.


mark
Re: The what if A65 67hp challenge. [Re: Allan Gill] #782201 08/22/19 4:23 am
Joined: Oct 2008
Posts: 5,741
DavidP Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Oct 2008
Posts: 5,741
Originally Posted by Allan Gill

Costs just as much to make something properly as it does it make something incorrect.

Then why didn't BSA do it properly?
It always seemed to me that the A65 was like the Combat Norton,a desperate attempt to wring modern performance from an antique design. At least Norton improved the bearings after that fiasco. BSA didn't even bother to update their oil system.


Stepping on others doesn't make you stand tall.

71 A65L "Zelda"
92 BMW K100rs "Gustav"
72 T120V cafe project "Mr. Jim"
72 T150V "Wotan"
Re: The what if A65 67hp challenge. [Re: DavidP] #782202 08/22/19 4:58 am
Joined: Jan 2014
Posts: 414
N
NickL Offline
BritBike Forum member
Offline
BritBike Forum member
N
Joined: Jan 2014
Posts: 414
Originally Posted by DavidP
Originally Posted by Allan Gill

Costs just as much to make something properly as it does it make something incorrect.

Then why didn't BSA do it properly?
It always seemed to me that the A65 was like the Combat Norton,a desperate attempt to wring modern performance from an antique design. At least Norton improved the bearings after that fiasco. BSA didn't even bother to update their oil system.


Machining heads at that time cost plenty on a production line.

Antique designs, well the turner design trumpets carried on until the 80's with few changes.
The a65 was a 'new' design in 1962 when launched, all triumph did was made theirs unit construction.
Norton tried using cheap bearings as a cost saver and that failed, beezer never did that. So many would have been saved if
they had just fitted an oil filter. The a65 motor is a sound old thing really, and oil tight if put together properly.
The old saga of the TS bush keeps coming up but there's nothing wrong with it when used with clean oil.
That's what cars are using. Many a10's did huge mileage as did early triumphs with a bush main.
It needed a non-return valve setup that lasted too.
Having used one in a sidecar outfit i've a lot of respect for the abuse the motor will stand when absolutely thrashed.
(even 2 years with a standard TS bush! as a 650 and 750!)
Shouldn't triumph have tried to cure the oil leak problems they had? or the timing gear rattles? It took 'em long enough
to get the bloody things to handle eh?
You could say similar stuff about all of 'em really, they were good enough in their day and that was a long time ago.

Re: The what if A65 67hp challenge. [Re: DMadigan] #782203 08/22/19 5:10 am
Joined: Jan 2014
Posts: 414
N
NickL Offline
BritBike Forum member
Offline
BritBike Forum member
N
Joined: Jan 2014
Posts: 414
Originally Posted by DMadigan
Hopwood in his book states the attitude of the Managing Director that BSA and Triumph machinery must be equally prepared so it was unlikely they would have made the improvement to the A65. When Dan Macias visited the Triumph factory he saw they were finishing the Triumph twin ports on a drill press. Doug Hele told him not to mention it because the operator had been doing it that way for many years.
By May 1971 BSA was looking at a loss of 1m GBP so was hardly in the position to make any changes to the design.
I think the A70 was the only one with steel capped rods but not sure.
The 350 was a disaster because it was "designed" by Turner (who checked valve springs by stepping on them with his heel). Two broken crankshafts and one valve gear failure in 1500 miles. The cutaway picture of the engine shows the characteristic Turner sharp angle between the port and valve. Also, by '71 you think they would have figured out it was a bad idea to put the output sprocket between the clutch and gearbox.



The last of the a65's had steel capped rods, it depended what they had in the stores, a bit like iron oil pumps.
Turner was not a performance merchant, he hated the racing idea. BUT he did have a real result with the 500 twin in the 30's
then, what yankee maker would consider using overhead valves in a motorbike engine eh? Or even a foot gear change?

Re: The what if A65 67hp challenge. [Re: Mark Parker] #782205 08/22/19 5:34 am
Joined: Apr 2005
Posts: 2,559
Mark Parker Online Content OP
BritBike Forum member
OP Online Content
BritBike Forum member
Joined: Apr 2005
Posts: 2,559
I think the non-return valve thing is often the pumps leaking at the joint. Dave's comment is interesting heads being ported with a drill press frown and confirming that an A65 with more hp than a T120 was not wanted let alone one to out perform the flagship threes.

The thing is, a well made hemi head motor can be a great thing. Chrysler still make brilliant Hemi V8s, they have a different power delivery to multivalve V8s, enormous bottom end midrange and then they scream in a very Don Garlits sort of way, Toyota make a multivalve V8 petrol it's smaller than the Hemis but very bland in comparison to the massively more powerful psycho nature of the hemi. The base version is 470hp Toyota's multivalve feels like 180hp.


mark
Re: The what if A65 67hp challenge. [Re: Mark Parker] #782206 08/22/19 5:51 am
Joined: Jan 2014
Posts: 414
N
NickL Offline
BritBike Forum member
Offline
BritBike Forum member
N
Joined: Jan 2014
Posts: 414
With 6+ litres and fuel economy like that, hemi's are good compared to pent roof multi-valve motors?

When F1 start using hemi's again, i'll think they are comparable.

Re: The what if A65 67hp challenge. [Re: DavidP] #782207 08/22/19 6:39 am
Joined: May 2013
Posts: 5,937
Allan Gill Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: May 2013
Posts: 5,937
Originally Posted by DavidP
Originally Posted by Allan Gill

Costs just as much to make something properly as it does it make something incorrect.

Then why didn't BSA do it properly?
It always seemed to me that the A65 was like the Combat Norton,a desperate attempt to wring modern performance from an antique design. At least Norton improved the bearings after that fiasco. BSA didn't even bother to update their oil system.



Probably because they knew they were going to the wall and who promotes something that is going down the tubes.

Tony, part’s blown engine answers your question of how long would a 650 last with 67 horse power


beerchug
Re: The what if A65 67hp challenge. [Re: Mark Parker] #782208 08/22/19 8:20 am
Joined: May 2004
Posts: 4,130
B
BSA_WM20 Offline
BritBike Forum member
Offline
BritBike Forum member
B
Joined: May 2004
Posts: 4,130
Originally Posted by Mark Parker
It's not particularly hard to do the ports by hand. BSA could have done the ports at least to how they were designed rather than short cutting at the factory, it may have been saving them a little money and keep the A65 on parity with the Triumph twin which they also owned. In 1970 they knew the difference between the heads but didn't rectify the production, they could have had 8 more hp in 1971. In their day these bikes were among the fastest most powerful on the road, but they were about to be displaced, or by 1971 they were being displaced by the 750s and the power bikes from Japan.

It was hardly a time to throw away easy hp in what was a full-scale hp race. You can see this when the mighty Z1 Kawasaki turned up, it was called the King. It was developed as a 750 but Honda released the CB750 4, getting the jump. Kawasaki held off releasing their bike till they increased the displacement to 903cc the reason they did that was to sell bikes, they understood the power of power. Honda claimed 67hp Kawasaki trounced it with 82hp and 54.2ftlb, though it was heavy at 542lb. For perspective my 883cc A65 weighs around 360lb and produces 97hp and 71ftlb it also has a very wide power spread. It uses a bigger version of the oval port above, so I'm interested to see how that translates onto an otherwise stock engine.

BSA already knew how to fix all the problems with the A65, roller mains both sides would have reversed market resistance, 71 or earlier they had excellent steel capped rods, high volume oil pumps and they had the A70 showing great potential. But they sank money and effort into things like the Ariel 3. And also the 350s that were a good idea though eventually scrapped because of a shot to the foot.

The 350 was a missed opportunity, they could not get good power from it because the head design was poor, DH had made an error, easy to rectify with a new casting, but management told him no. So 34hp was the best they could ever get. The 350 Honda was already in the market with similar power, the BSA 350 could and should have made 45+hp, and it would have been a winner, it could then be more expensive than the Honda because it gave more, it had the advantage with a state of the art frame and running gear already. A company like Kawasaki would have made sure they had what they needed to get the power necessary. So rather than spend massive effort and money fruitlessly down these paths, BSA could have done three things, fixed the A65 engine completely, and at the same time, because its basically the same thing, developed the A70And the third, built at least a limited number of Rob North style Rocket threes, the frames were state of the art and exotic, cheaper to manufacture than the std frames. The threes also work extremely well at 850cc if they wanted to respond to the Z1 and Ducati's SS750 when they came along.



BSA could have done a lot of things but they had a board that were mainly bankers and technically illiterate "gentlemen of means & distinction "
I mean the board went against the decisions & advice of the entire engineering department and put the C 10 / C11 into production post WWII. a design that was obsolete , heavy & labour intensive.
The board vetoed the original A 50/65 design with a horizontal split crankcase because "it would not be BSA"
The board forced the oil filler on the OIF twin frame to go under the saddle thus loosing a lot of oil capacity because "Riders would accidentally put petrol into the oil hole"
The latter showed not one of them had every put petrol into anything cause a bowser nozzel will not fit.
When you have the decisions being made buy such a bunch , any fool with a slick tongue and a spreadsheet could get them to back any stupid idea.


Bike Beesa
Trevor
Re: The what if A65 67hp challenge. [Re: NickL] #782209 08/22/19 8:33 am
Joined: May 2004
Posts: 4,130
B
BSA_WM20 Offline
BritBike Forum member
Offline
BritBike Forum member
B
Joined: May 2004
Posts: 4,130
Originally Posted by NickL
A massive slice of their market was the 'states.
It would have been more of a benefit to make the a65 more reliable and long lived than to uprate it's horsepower.
The average bloke who bought a bike wasn'r racing it, he was riding it once a week and poorly maintaining it.
His mates with triumphs could get away with not changing oil etc so he would do the same...........the beezer went bang.
They should have shut down in 1963 and moved production to the far east, that way they would have had local access to
a massive market and government funded factories/development. Competing with japan's zero interest rate for business at
that time was impossible, they could product dump anywhere in the western world with government backing, and they did.
Beezer was nothing compared to the yankee electronics industry they devastated.
The management at beezer were just selling it all off and getting out, they didn't want to make motorbikes, they wanted to
make money. Pi$$ing about modifying cylinder heads on an out of date engine that's been in production for 10+ years
is the sort of thing that makes firms go broke.
I understand the nostalgia and i love the old crates as well, but politics and economics etc. get in the way.


Been looking at why the board did things for a very long time.
The only thing I can see is all through the 40's, 50's & early 60's every one knew that the USA & the USSR would go hammer & tongs into WWIII
And WWIII would be big money for BSA as WWI & WWII had been, it is just that it never happened.
Everything BSA pought was a stratigically important industry in a war.

Also remember that motorcycles had never ever made BSA much profit.
The profits came from guns , powder metallurgy, coal handling , home furnaces, air conditioning, lathes, mills tooling , steel, coal mines and all the other things that BSA was into.
By the time the board realized that they HAD to make a profit from motorcycles it was too late ,


Bike Beesa
Trevor
Re: The what if A65 67hp challenge. [Re: DMadigan] #782210 08/22/19 8:47 am
Joined: May 2004
Posts: 4,130
B
BSA_WM20 Offline
BritBike Forum member
Offline
BritBike Forum member
B
Joined: May 2004
Posts: 4,130
Originally Posted by DMadigan
Hopwood in his book states the attitude of the Managing Director that BSA and Triumph machinery must be equally prepared so it was unlikely they would have made the improvement to the A65. When Dan Macias visited the Triumph factory he saw they were finishing the Triumph twin ports on a drill press. Doug Hele told him not to mention it because the operator had been doing it that way for many years.
By May 1971 BSA was looking at a loss of 1m GBP so was hardly in the position to make any changes to the design.
I think the A70 was the only one with steel capped rods but not sure.
The 350 was a disaster because it was "designed" by Turner (who checked valve springs by stepping on them with his heel). Two broken crankshafts and one valve gear failure in 1500 miles. The cutaway picture of the engine shows the characteristic Turner sharp angle between the port and valve. Also, by '71 you think they would have figured out it was a bad idea to put the output sprocket between the clutch and gearbox.


BSA MOTOORCYCLES were loosing money.
The other divisions were making money, enough to pay down the motorcycle divisions debt . Why do you think the corperate criminal Dennis Poore quietly transferred these non motorcycling assets into his own company Manganese Bronze ?
The killer was the way the money morons had taken advantage of the post WWII British tax system to avoid paying any tax by debt financing every years production, a risky financial system that requires you to turn a profit each & every year.
As for not having the money to make last minute changes, steel capped rods, cast iron oil pumps, they were working away but the flagship fast bike was the A75 and making the A65 better & faster than the A 75 which was winning races & getting good publicity was never going to happen.

As for Mr Turners engineering, the less said about it the better.
What is oft overlooked that he was the persons who had resurrected Ariel a company that was bankrupt when he became the chief engineer but the real engineers at Ariel made his ideas work
He then went on to do the same thing to the again bankrupt Triumph, again because the real engineers made his designs work.
So to the uninformed & engineering illiterate members of the board Turner was a God that could fix anything and nothing he said could be questioned by anyone.
The problem was Sangster knew he was really only a stylist and allowed the real engineers under him to fix his short comings . The board did not and gave him absolute authority so they were on the road to dissaster.

Last edited by BSA_WM20; 08/22/19 8:55 am.

Bike Beesa
Trevor
Re: The what if A65 67hp challenge. [Re: Allan Gill] #782211 08/22/19 9:13 am
Joined: May 2004
Posts: 4,130
B
BSA_WM20 Offline
BritBike Forum member
Offline
BritBike Forum member
B
Joined: May 2004
Posts: 4,130
Originally Posted by Allan Gill
Originally Posted by DavidP
And if BSA had actually done this to every production model they would have had to charge how much for each bike? They had enough trouble selling them at the price they charged.
Looks like a fun project though.


Costs just as much to make something properly as it does it make something incorrect.

Be interested to know what the difference in the blueprint head and the other heads. theres 2 casting/part numbers for the OIF 2 carbs heads, a few suttle differences between them, but never measured the ports..... too late now as both of them are modified.



20:20 hindsight is a wonderful thing Allan.
What we know in 2019 was not known in 1962.
We forget that all BEESAS were designed with slide rules.
It would be another 20 years before reliable computer modelling became available.
Port design changes had to be made in metal by hand then tested to failure a very slow & expensive process.
Look at the bore to stroke ratios, once they found one that worked it never got changed. you can trace most of them back to the 20's. A 65 sort of excluded.
We also have to remember that to the BSA board, their competition was Enfield, Norton and the failing AMC.
Untill the Honda 4 appeared there was no competition to the superiority of the British motorcycle because they were British and the Japanese will never be able to make a real mans motorcycle.
This was the attitude of the board, in fact it appears several times in minutes of board meetings.
So if you can sell all that you can make, why spend money to make it better ? , another attitude that appears in board minutes for decades .


Bike Beesa
Trevor
Re: The what if A65 67hp challenge. [Re: Mark Parker] #782212 08/22/19 9:26 am
Joined: Apr 2005
Posts: 2,559
Mark Parker Online Content OP
BritBike Forum member
OP Online Content
BritBike Forum member
Joined: Apr 2005
Posts: 2,559
How long would it last with 67hp is an interesting question. For a manufacturer you want indestructability as a high priority, right along side the priority of finding the best hp.

Did you know what Rolls Royce did with the Merlin engine? 33 prototypes, before the first production model with 1035hp was used in Hurricanes and Fairey Battles, and then, it was very unreliable. But Rolls Royce started taking random engines from the production line and ran them at full power on the test bed until they failed, then when they could find the cause, they redesigned until they fixed it, and the Merlin became one of the most reliable aero engines ever, even with power boosted to 2030hp in some Spitfires. In 1944 they had a Merlin on the test bed with 2,640hp. From around 50hp per liter to almost 100hp per liter. Rolls Royce didn't even think that sort of output was remotely possible and were developing the bigger Griffin engine.

My 883 is putting out almost 110hp per liter.

I don't want to run my engines for hours on a dyno at full noise, but factories need to do it and make sure they are up to it, because customers somewhere are going to do it. Why modern cars and bikes have rev limiters. Reminds me of the framed poster in the Toyota workshop with a picture of a mechanic and a car, listing some of the things experienced technicians would carefully check on the pre-delivery of your new vehicle, the apprentice had crossed them all out and written in 'Rev Limiter'. You can actually beat a rev limiter by throwing things back a gear or two. We had a Corolla come in that had spat most of the valve actuating gear out, the lady had changed back to a lower gear to pass a truck, possibly from 5th to 2nd or 4th to 1st at a guess.


mark
Re: The what if A65 67hp challenge. [Re: Mark Parker] #782215 08/22/19 10:54 am
Joined: Oct 2012
Posts: 4,680
Hillbilly bike Online Content
BritBike Forum member
Online Content
BritBike Forum member
Joined: Oct 2012
Posts: 4,680
Originally Posted by Mark Parker
I think the non-return valve thing is often the pumps leaking at the joint. Dave's comment is interesting heads being ported with a drill press frown and confirming that an A65 with more hp than a T120 was not wanted let alone one to out perform the flagship threes.

The thing is, a well made hemi head motor can be a great thing. Chrysler still make brilliant Hemi V8s, they have a different power delivery to multivalve V8s, enormous bottom end midrange and then they scream in a very Don Garlits sort of way, Toyota make a multivalve V8 petrol it's smaller than the Hemis but very bland in comparison to the massively more powerful psycho nature of the hemi. The base version is 470hp Toyota's multivalve feels like 180hp.

The new Chrysler Hemi is not a true hemi but more like an oval using twin spark plugs...And The Chevy LS V8 can match or exceed a new Hemi in power using a wedge head combustion chamber with two inline valves..And the Chevy engine is less weight and more compact...

The A65 has a better head design than a Triumph ...Jim Rice in the 70's did ok on flat track racing with his 750 BSA until the XR750 Harleys got better tuned...At that time a Triumph 750 built by CR Axtell made about 72 HP. I don't know is that was crank or RWHP So the 750 BSA was making the same or a bit more..I don't know if flat track bikes were tuned to get every possible bit of power like drag race engines..


79 T140D, 96 900M Ducati ....On a bike you can out run the demons..
Page 1 of 9 1 2 3 4 5 6 7 8 9

Moderated by  Allan Gill, Jon W. Whitley 

Home | Sponsors | Newsletter | Regalia | Calendar | Bike Project | BritBike Museum | Spiders Cartoons | DVD- Manuals & Parts books
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
Powered by UBB.threads™ PHP Forum Software 7.7.3