Dunstall: Performance Guru or marketing genius...?

ando said:

Well I can speak from experience as a long term owner of an 810 Dunstall.

The Dunstall cam is original and is still in good condition, or it was at the last rebuild. I have memories of Honda camshafts, particularly the smaller engine Hondas wearing the lobes off the cam at very low mileages.
Ando

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I went to his shop sale at Dunstall Well Hall Road before he shut down, and in there was at least 2 full race cams that looked as if the lobes were not hardened- the amount of wear on those lobes had to be seen to believe. There was also a full Norton full race cam where the high lobes were acquired by grinding a flat every 5 degrees, not done on any cam grinding machine at all :!: :shock:
All these were for sale at £30.
The street came that I purchased in the post from Paul Dunstall has the lobes out 5, 6 , and 11 degrees, only one was correct when I finally got round to checking with a degree disc, this cam was effetely making my bike SLOWER :!:
Normal service was resumed when I replaced with the SS Norton that I originally came with the bike –mini wheelies from the traffic light Grand Prix as well as accelerating better
Sorry, but in my opinion a lot of this stuff is JUNK :!:

Bernhard

No disrespect but when shops close all the junk from the back room is usually sold for whatever they can get for it

the full race cams you refer to were most likely reject items included in the sale

don`t forget Genuine factory Commando cams had issues with hardness when Norton were cost cutting in the 1970`s

Dunstall was very good at making contacts that others could not be bothered with. Blair is a case in point. But the execution of mine was terrible - perhaps it was from a bad batch .And he pioneered Disk brakes. Cams are a bit of a thorny subject what many do not realise is that a rebuilt engine with a new cam should never be allowed to idle. Again twice when I was in Well Hall customers had issues with the 810 kit ,maybe some batches were better than others and its possible they had been badly fitted. But the quality of the body parts was very variable some by design. The Jubilee clips used to secure the front Mudguard that was tacky , and from an engineering point of view not good. Forks need bracing.It was however possible to buy after market kit that was well made and I do not see why Dunstall could not have found better suppliers. Its all a question of attitude. And to be candid it was not always good. Gus Kuhn's sold similar stuff and of much better quality.

oldmikew said:

Dunstall was very good at making contacts that others could not be bothered with. Blair is a case in point. But the execution of mine was terrible - perhaps it was from a bad batch .And he pioneered Disk brakes. Cams are a bit of a thorny subject what many do not realise is that a rebuilt engine with a new cam should never be allowed to idle. Again twice when I was in Well Hall customers had issues with the 810 kit ,maybe some batches were better than others and its possible they had been badly fitted. But the quality of the body parts was very variable some by design. The Jubilee clips used to secure the front Mudguard that was tacky , and from an engineering point of view not good. Forks need bracing.It was however possible to buy after market kit that was well made and I do not see why Dunstall could not have found better suppliers. Its all a question of attitude. And to be candid it was not always good. Gus Kuhn's sold similar stuff and of much better quality.

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err,,, no, Rickmann did that. they first came out on the Rickman metisse ridden by Alan Barrnet of Iver on the Tom Kirby Metisse;

http://www.bing.com/images/search?q=ala ... ajaxhist=0

http://www.bing.com/images/search?q=ric ... ajaxhist=0

The twin discs that you might be referring to was developed by Robinson –who later sold the Patent rights of it to a Japanese firm for a 5 figure sum :!:

Bernhard said:

oldmikew said:

Dunstall was very good at making contacts that others could not be bothered with. Blair is a case in point. But the execution of mine was terrible - perhaps it was from a bad batch .And he pioneered Disk brakes. Cams are a bit of a thorny subject what many do not realise is that a rebuilt engine with a new cam should never be allowed to idle. Again twice when I was in Well Hall customers had issues with the 810 kit ,maybe some batches were better than others and its possible they had been badly fitted. But the quality of the body parts was very variable some by design. The Jubilee clips used to secure the front Mudguard that was tacky , and from an engineering point of view not good. Forks need bracing.It was however possible to buy after market kit that was well made and I do not see why Dunstall could not have found better suppliers. Its all a question of attitude. And to be candid it was not always good. Gus Kuhn's sold similar stuff and of much better quality.

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err,,, no, Rickmann did that. they first came out on the Rickman metisse ridden by Alan Barrnet of Iver on the Tom Kirby Metisse;

http://www.bing.com/images/search?q=ala ... ajaxhist=0

http://www.bing.com/images/search?q=ric ... ajaxhist=0

The twin discs that you might be referring to was developed by Robinson –who later sold the Patent rights of it to a Japanese firm for a 5 figure sum :!:

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Yes you are right I was thinking of the twin disc set up - had not realised that it was designed by Robinson. He was selling 4 and 8 leading shoe drum brakes of his own
manufacture certainly as late as 74. A five figure sum was an enormous amount of money then. Thanks for the links

Re “A five figure sum was an enormous amount of money then.”
I cannot recall where I heard this, it was either a magazine article on Robinson or a Channel 24 ( I think :!: ) program on bikes. Either way …. He was laughing all the way to the bank and booking a family cruise to the Caribbean :!:

Not aware that Robinson ever did the 8 Leading shoe front brake, But Dave Dregens of Dresda
did make a couple of batches.

http://www.britbike.com/forums/ubbthrea ... ber=198371

Degens did indeed design the 8 leader and set up the guy who was CMA to machine them. Said guy later went into producing cast wheels and was famous for the 3 spoke CMA. Sadly, one of them came out of the lathe and killed him!

Robinson made a 4 leading shoe brake, very popular with the café crowd but no good for racing. They faded badly. Degens told me he thought they were cast from the wrong alloy and it expanded too much. I don't know if this is true, but it matches my own experience, I raced one and had to make up an adjuster that I could adjust during the race, after the race when cool, the brake would be on solid as the drum had clearly shrunk so much!

I replaced the stock Interstate mutes in the late 70's after they both rotted out. I've had a pair of Dunstalls on her ever since. Maybe I just happened to get a good pair when the chrome bath was running true... That's my sole experience with Dunstall goods.

Nathan

Bernhard said:

err,,, no, Rickmann did that. they first came out on the Rickman metisse ridden by Alan Barrnet of Iver on the Tom Kirby Metisse;

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The first race win with a disc front brake is attributed to Bill Ivy, on a Tom Kirby G50 Metisse, in March of 1966 at Mallory Park. Ivy had other race commitments so was replaced on Tom Kirby's bikes by John Hartle, Alan Barnett was riding Metisse in '66 but didn't replace John as 'development rider' until after John was killed at Scraborough in August 1968. By then the major development effort will have been around the Triumph based 700 8 valve Metisse, that development formed the basis of the Weslakes of later years.

Griff Jenkins raced Rickman Norton's through this period, he was fielded by Paul Dunstall, who moved all of his engines into Rickman frames working with Rickman, including of course the 750 Atlas versions, the design of this frame remained in production for around 10 years and my own Rickman Norton uses a frame from the last batch of 5, produced in October '75. My order of a full chassis gave them the 5 they needed to actually produce the batch and I dropped in a trick 850 motor in around 3 months. (although I sold the bike in 1980 the frame is the one in my current race bike, now in it's first season of racing after a 6 year build, and now running a 750 short stroke using a Maney bottom end and Fullauto head)

I was not really aware years ago of Dunstall's involvment with Rickman, but he clearly saw a good product when he saw one, apart from upgrading his racers his plan was to sell race and cafe racer bikes based on the Rickman frame/Atlas engine, which I don't think really got off the ground before he was messing with his own low boys.

I have only ever owned/used one Dunstall product, a 2 into 1 into 2 exhaust I got of a crashed '72 road bike I bought one Monday evening after a Sunday blow up and pulled the engine out of in a desperate attempt to finish a race season, running Saturday racing again Sunday but got T boned whilst running 2nd!).

My own ex Thruxton short stroke head had Thrixton made exhaust stubs used when the fitted engines into the space frames. so I needed pipes to fit in the standard type threaded rose head. I hacked the donor exhaust to create a short primary 2 into 1 which worked surprisingly well the one (short) time I used it.

Fast Eddie said:

Degens did indeed design the 8 leader and set up the guy who was CMA to machine them. Said guy later went into producing cast wheels and was famous for the 3 spoke CMA. Sadly, one of them came out of the lathe and killed him!

Robinson made a 4 leading shoe brake, very popular with the café crowd but no good for racing. They faded badly. Degens told me he thought they were cast from the wrong alloy and it expanded too much. I don't know if this is true, but it matches my own experience, I raced one and had to make up an adjuster that I could adjust during the race, after the race when cool, the brake would be on solid as the drum had clearly shrunk so much!

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I understood the Seeley 2 x SLS drum brake was made by Robinson!

Hi Steve

Think I have told you this but its worth telling others. I picked up a couple of the Rutter developement back plates, unfortunately my Hub turned out to be cracked. However I asked Colin Seeley about the rairity of the braking parts & he laughed & said they were G50 rear brake shoes
Good business man.
Steve great to see you out on the bike, hopefully get to see you ride at Lydden.

Nige, please such unkind words again about such a beautiful brake as the Robinson 4 leader The key is to set it up like I do!
It drags to begin with Cant push it up the hill from the paddock at Cadwell, however by the second lap its grand.

I have had a few Dunstall bits. Could not give his breadbin fibreglass wideline tank away for love nor money.
My first set of pipes were excellent, after that they fell to bits & sounded awful as they did so. Lots of rearsets, they turned out to be made by a man in Devon! Liked the road based race fairing with the instrument panel inside it. I think he did really well for the period. Not saying I would buy anything now days cos I wouldnt.

all the best Chris

Chris said:

Hi Steve

Think I have told you this but its worth telling others. I picked up a couple of the Rutter developement back plates, unfortunately my Hub turned out to be cracked. However I asked Colin Seeley about the rairity of the braking parts & he laughed & said they were G50 rear brake shoes
Good business man.
Steve great to see you out on the bike, hopefully get to see you ride at Lydden.

Nige, please such unkind words again about such a beautiful brake as the Robinson 4 leader The key is to set it up like I do!
It drags to begin with Cant push it up the hill from the paddock at Cadwell, however by the second lap its grand.

I have had a few Dunstall bits. Could not give his breadbin fibreglass wideline tank away for love nor money.
My first set of pipes were excellent, after that they fell to bits & sounded awful as they did so. Lots of rearsets, they turned out to be made by a man in Devon! Liked the road based race fairing with the instrument panel inside it. I think he did really well for the period. Not saying I would buy anything now days cos I wouldnt.

all the best Chris

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Didn't realise you'd got one Chris...

Maybe you misread my post...

I was trying to say how good I thought they were...

Honest.

SteveA said:

Bernhard said:

err,,, no, Rickmann did that. they first came out on the Rickman metisse ridden by Alan Barrnet of Iver on the Tom Kirby Metisse;

Click to expand...

The first race win with a disc front brake is attributed to Bill Ivy, on a Tom Kirby G50 Metisse, in March of 1966 at Mallory Park. Ivy had other race commitments so was replaced on Tom Kirby's bikes by John Hartle, Alan Barnett
I was not really aware years ago of Dunstall's involvment with Rickman, but he clearly saw a good product when he saw one, apart from upgrading his racers his plan was to sell race and cafe racer bikes based on the Rickman frame/Atlas engine, which I don't think really got off the ground before he was messing with his own low boys.

Click to expand...

You are quite right, gosh, I had forgotten about Bill Ivy, who can remember him throwing the 500 about at Brands Hatch, and his “two wheel drift” into Kidney Bend going onto Clearways on the Indy short circuit had to be seen to be believed.

You are quite right, gosh I had forgotten about Bill Ivy, who can remember him throwing the 500 about at Brands Hatch, and his “two wheel drift” into kidney bend going onto Clearways on the Indy short circuit had to be seen to be believed.
As you said Dunstall did use other manufactures here’s an early version of his much later spine frame Norton 750 ridden by Lance Weil;

http://2.bp.blogspot.com/-leY5_SZz8vw/T ... l+domi.jpg

There was an early version of the 1967 MV Agusta 600-4 –the brakes were operated by cable :!:

http://www.bing.com/images/search?q=m+v ... ajaxhist=0

also;
http://www.bing.com/images/search?q=m+v ... ay&first=1

also;
http://www.vintagemotorcyclesonline.com ... usta-600-4

Bernhard said:

As you said Dunstall did use other manufactures here’s an early version of his much later spine frame Norton 750 ridden by Lance Weil;

http://2.bp.blogspot.com/-leY5_SZz8vw/T ... l+domi.jpg

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Now that is a Lyster frame. Lyster was also an early adopter on disc brakes.

The Low Boy had no front down tubes, with the fuel tank fitted it looked a bit like a Seeley MkIII with a vertical drain pipe section for the oil tank.

A name that ought to be mentioned in the context of Dunstall , is the late Jim Boughen formerly of the AMC race shop where he worked with Jack Williams . He was responsible for the big valve heads that Dunstall marketed , and may well have built some of the engines for Dunstall' race bikes. Certainly he built the Gus Kuhn Nortons and these were faster than the factory racers of the early 70s. He died a couple of years ago age 97 his passing not even noticed by the Norton Owners club here in the UK

Jim Boughen gets a couple of mentions here and there for his work with the AMC Race Shop and Gus Kuhn racers.
eg
http://www.guskuhn.net/GKMLtd/Racing/1996TrackTest.htm

Thank you for the excellent link.. Wonder what the 'heavy metal' from Harwell was - used to balance the crank on the Kuhn
engines?

oldmikew said:

Thank you for the excellent link.. Wonder what the 'heavy metal' from Harwell was - used to balance the crank on the Kuhn
engines?

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Tungsten I think... Happy to stand corrected on this though...

Good article, I have read it before.....having decided to remain firmly with standard valves in my Fullauto for use on UK shorts circuits I loved this bii of wisdom....

'"We used standard valve springs and inlet valves when I did the engines," recalled Boughen. "The big valves affected traction on short circuits and only showed up well on fast circuits like the Isle of Man, but I'd stopped doing Kuhn's engines by '73 and they probably fitted the big valve head for Imola, which was a very fast track in those days".

And having ridden a rigidly mounted motor with standard Carillo rods I totally understand how Cathcart felt about the vibes....