Dunstall 810 kit - really that bad?

Hello!

I have just joined this forum because I plan to fulfill my dream of a birth year Commando. I have been offered a nice ´71 which has been restored by the PO. He claims that the bike has a 810 kit from Dunstall as well as high performance valves, bronze valve guides, valve springs, copper head gasket, MK5 SS Street cam, etc from Dunstall. There are no invoices backing up this claim, but I do not expect he is lying. What concerns me more is all the bad mouthing i read about the 810 kits from Dunstall. Are they really that bad?

Performance is less important to me than reliability - I have too many bikes already and for outright power there are other options

Regards from Norway where the roads are getting slippery!

Morini

Easy to tell if they are 810 barrels they are alloy and not cast iron. They should have 810 stamped on the side; a magnet will confirm whether they are. 810 Piston rings are, I believe, v.difficult to obtain.
Bronze vale guides are not as durable as the original cast iron ones, it’s a don’t ask me how I know question, I tried them.
Dunstall cams are out on the lobe timing in my experience, as much as 11 degrees :!: – so if you time the lobes with the valves opening with a degree disc-don’t be surprised-but the odd good one was made.
Any engine can be made reliable; it’s just a matter of expertise and riding within its limits

morini said:

Hello!
Performance is less important to me than reliability - I have too many bikes already and for outright power there are other options

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If that is true, you might be better off to keep looking.
High performance (Dunstall / Combat), especially as executed (poorly) back in the day tends to have the opposite effect.
There are plenty of '71 Commandos out there that would be better starting points for a reliable, yet fun ride.

That being said, my Combat is a blast to ride and has been tweaked in various ways so that readability is now part of the equation too.

I thought that the Dunstall stuff was "top of the line" from "back in the day"

But this is coming from someone that just entered into the Britt bike hobby.

jaguar said:

I thought that the Dunstall stuff was "top of the line" from "back in the day"

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More "BLEEDING edge" than "LEADING edge", as they say.

There WERE highly competitive and one of very few (as typically the case) aftermarket high performance suppliers for Commando. Dunstall was actually considered a manufacturer, and GENUINE Dunstall bikes are titled as such (not Norton).

Over time, some of the big bore kits have shown their weak points. Some manifested themselves pretty early on, but that was in actual racing situations for the most part.

jaguar said:

I thought that the Dunstall stuff was "top of the line" from "back in the day"

But this is coming from someone that just entered into the Britt bike hobby.

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Dunstall did good work on race bikes, but their production items were sorely lacking quality.
From what I have read, their parts suppliers cut too many corners in order to make a profit.
I had original Dunstall pipes and mufflers on a '71 back in the day and I can remember them falling off at the most inopportune times.

grandpaul said:

snip
Dunstall was actually considered a manufacturer, and GENUINE Dunstall bikes are titled as such (not Norton).
snip

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Can you provide some legal back up for this statement?

I have often and ONLY heard that 1967 is the ONLY year that the British govt acknowledged Dunstall as a Marque. In 1968 the racing sanctioning body "allowed" dunstall prepped bikes to run as "dunstall".

Even my 1968 "dunstall" Atlas, which NOC records show factory delivery to the Dunstall dealership, was not titled as a dunstall. I'm the 5th owner and know the lineage and have met the 4th, 3rd and 2nd owners and talked to them all. It's a "NORTON" modified by dunstall by order for an American service man. Then imported to the USA.
http://atlanticgreen.com/dunstall.htm

dynodave said:

grandpaul said:

snip
Dunstall was actually considered a manufacturer, and GENUINE Dunstall bikes are titled as such (not Norton).
snip

Click to expand...

Can you provide some legal back up for this statement?

I have often and ONLY heard that 1967 is the ONLY year that the British govt acknowledged Dunstall as a Marque. In 1968 the racing sanctioning body "allowed" dunstall prepped bikes to run as "dunstall".

Even my 1968 "dunstall" Atlas, which NOC records show factory delivery to the Dunstall dealership, was not titled as a dunstall. I'm the 5th owner and know the lineage and have met the 4th, 3rd and 2nd owners and talked to them all. It's a "NORTON" modified by dunstall by order for an American service man. Then imported to the USA.
http://atlanticgreen.com/dunstall.htm

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I cannot provide legal backup for that claim, I read it in a Norton book somewhere and had never heard otherwise.

Thanx for clearing that up, Dave.

I had read a ref the UK allowing Dunstall to be recorded as a separate brand but it probably would only have counted within the UK, however if you use the Vehicle Search on the current DVLA site the drop down menu for selecting the manufacturer does not include Dunstall so it may have been only in the mind of Paul D. The drop down menu does have a lot of manufacturers listed including lot volume UK makers, ever heard of BRIT JEFFREY DIAMOND, neither have I and they are listed.

tomspro said:

morini said:

Hello!
Performance is less important to me than reliability - I have too many bikes already and for outright power there are other options

Click to expand...

If that is true, you might be better off to keep looking.
High performance (Dunstall / Combat), especially as executed (poorly) back in the day tends to have the opposite effect.
There are plenty of '71 Commandos out there that would be better starting points for a reliable, yet fun ride.

That being said, my Combat is a blast to ride and has been tweaked in various ways so that readability is now part of the equation too.

Click to expand...

I agree with this....keep looking for a standard Commando. Andover build quality and reliability is better than Dunstall.

When I were a lad, the Dunstall Suzuki was the fastest bike on the road, classed as a manufacturer therefore as far as I recall.

Anyway, I don't think we should rely on the DVLA site, Dresda, Egli, Seeley, Healey, even Rickman were all manufacturers and are not on that list.

tomspro said:

I had original Dunstall pipes and mufflers on a '71 back in the day and I can remember them falling off at the most inopportune times.

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I see that sentiment so often in this forum, I wonder how I managed on my mufflers. The stock Interstates rotted out around 5000 miles (late 70's), when I swapped for a pair of Dunstalls. 12,000 miles later with no sign of failure. ???

tomspro said:

...their parts suppliers cut too many corners in order to make a profit.
I had original Dunstall pipes and mufflers on a '71 back in the day and I can remember them falling off at the most inopportune times.

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That's my recollection as well. They certainly were also hampered by sketchy quality on some of their products that was definitely down to the farmed-out work and not being able to get hardly anything made properly out of Britain in the early-mid 70's due to the difficulty with labour relations and many negative attitudes that were rampant at the time.

FWIW, my Dunstall 2-1-2 exhaust and mufflers that I bought in 1974 for my 73 850 never let go or gave any problems other than being extremely fiddly to fit properly. It took a great deal of loose fit maneuvering to snug things up properly, but it worked. I have heard of other that were built too far out-of-spec to fit properly and like your situation, they were a PIA.

Fast Eddie said:

When I were a lad, the Dunstall Suzuki was the fastest bike on the road, classed as a manufacturer therefore as far as I recall.

Anyway, I don't think we should rely on the DVLA site, Dresda, Egli, Seeley, Healey, even Rickman were all manufacturers and are not on that list.

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Agreed.

I don't think you'll easily find "legal" documentation to that effect, and it really doesn't matter. If one has a Dunstall VIN'd bike it is a Dunstall, based on the British Government's making it so. I'm not going to troll through UK government legislation for something that has already been widely reported in the press of the day and subsequently, doesn't make sense to me.

I recall from my Commando days in the early-mid 70's that Dunstall was considered a manufacturer in Canada and , IIRC, by the US motorcycle magazines of the time. What will naturally cause plenty of confusion and difficulty is that like Rickman, etc., they had an even bigger presence in aftermarket parts than complete bikes.

Broken link removed

As the owner of a high mileage 810 Dunstall I can say that my experience with the bike is no worse than I would expect from Norton Factory parts.
My bike is fitted with a Dunstall cam. The lobes are not out of sync and the cam is in good condition after more miles than most Norton factory cams are capable of. The cam also performs exceptionally well.
The only problem that I had with engine parts was the studs pulling out of the cylinders which happened at less than 30,000 miles. The cylinder was fitted with threaded bushes or thread inserts and I have not had any further problems.
The fibreglass parts were the poorest quality Dunstall parts but were comparative with similar parts from other manufacturers of the time.
Most of the critics have not and do not own a Dunstall, just as most Norton critics do not own a Norton
ando

jaguar said:

I thought that the Dunstall stuff was "top of the line" from "back in the day"

But this is coming from someone that just entered into the Britt bike hobby.

Click to expand...

Perhaps you would care to read an earlier discussion brought up by Fast Eddie on this website;

dunstall-performance-guru-marketing-genius-t22930.html?hilit=Was dunstall parts that bad?

Fast Eddie said:

When I were a lad, the Dunstall Suzuki was the fastest bike on the road, classed as a manufacturer therefore as far as I recall.

Anyway, I don't think we should rely on the DVLA site, Dresda, Egli, Seeley, Healey, even Rickman were all manufacturers and are not on that list.

Click to expand...

Way back in the 1970s the D.O.T. might have given Dunstall his own brand for a short period, but apart from road racing and the like, Dunstall did not as a rule make his own chassis which is where the DOT gives a log book for registration. Dunstall closed up shop when he quit motorcycles for the building trade, either the DOT made the rules stricter or he quit bikes, whichever came first.
Firms like Dresda e.t.c do make their own chassis even if they use other manufactures engines and are classed as a motorcycle company in their own eternity

Hi
Back in the day, I traded in my 1968 Firebird scrambler for a 1971 Norton roadster.
I first bought the 810 kit & high performance street cam. It was faster than stock!
A couple of years later I added the 2 into one into 2 exhaust & Decible silencers. It got a little faster.
Then I added the Dunstal big valve head.
The bike became very fast for its day, beating the 750 triple Kows. And ate Harleys for lunch!

I had 2 timing slips for 11.7 quarter miles At New England dragway. It was ridden every day! ( New England riding days) until about 1987 with out any problems other than the exhaust port threads.

I sold it to make a few mortgage payments on my new house.
So after doing the Hop up thing once, I went the supercharger route, the next time around.
Now we have great people making better Norton parts, Heads, Cylinders, cams Etc. using much better technology, but back in the day Dunstal was the only game in town.

If you have the 810 kit, then it should be able to work just fine! If nothing else , it will save about 20 pounds ( Weight)

Bruce MacGregor

'Dunstall cams are out on the lobe timing in my experience, as much as 11 degrees :!: – so if you time the lobes with the valves opening with a degree disc-don’t be surprised-but the odd good one was made. '

Would you ever time it any other way ?