Norton Dunstall 810 head, NOS question. Is this head considered NOS?

[JACKYBOY]

I purchased complete dunstall 810 head from Alex McLean of motorcycles unlimited , Corte Madera CA. somewhere around 1978,79,80. The head was is in the parts showroom and was sold to me as new. complete with valves, springs. cups , keepers, spindles etc. I bought it for a project i had: A 1971 commando 750 that already had many dunstall parts minus the engine. The bike was stolen before i could complete it but I hung to this for all these years. So is this considered NOS?? Or technically aftermarket? Opinions would be appreciated, Im considering putting it on ebay.

 

[marshg246]

If never mounted on an engine, I would call it NOS, but not Norton NOS. Anything can be NOS. On eBay you should list it as New, Other and then give a full description in the details.

 

[L.A.B.]

So is this considered NOS?? Or technically aftermarket?

Unfortunately, you haven't posted any pictures of the underside of the head/combustion chambers.
What diameter are the inlet ports?

 

[L.A.B.]

Atlantic Green website: about 810 Dunstall head

Hi. The Atlantic Green/Dyno Dave web site says: “ 71 head with a "rotated away from exhaust" big intake valve Dunstall conversion. It has 32 mm intake ports. The squish band being completely machined away. It was for use with a Dunstall 810 barrel kit and the R3 cam which was very similar to...

www.accessnorton.com

 

[JACKYBOY]

Unfortunately, you haven't posted any pictures of the underside of the head/combustion chambers.
What diameter are the inlet ports?

The inlet ports are 1 1/4, inlet valves are 1 5/8.

 

[L.A.B.]

View attachment 101955View attachment 101956

The inlet ports are 1 1/4, inlet valves are 1 5/8.

That appears to be a Dunstall head (see the link in my previous message).
So it would be considered an 'Unused Dunstall head' then, I guess.

 

[JACKYBOY]

If never mounted on an engine, I would call it NOS, but not Norton NOS. Anything can be NOS. On eBay you should list it as New, Other and then give a full description in the details.

It's never been on an engine but I think listing it as "new" seems like the right way to go, Thanks for your imput.

 

[Schwany]

Appears to have been media blasted and surfaced to the max. Definitely bigger valves. It would get the job done for a high CR build. I sort of doubt it is new though. I see traces of black in pockets here and there. Dunstall modified, unused, and in perfect condition maybe. Somebody will buy it.

 

[Longtimegone]

Nice looking head. Are those transfer marks from washers around the head bolt holes, or were they cast that way?

 

[JACKYBOY]

Nice looking head. Are those transfer marks from washers around the head bolt holes, or were they cast that way?

I never noticed that. You have a keen eye. Without having a new head to compare they sure to appear to be transfer marks. Ive gone from Nos to: new, to like new! I never had it on my bike for sure but those look to be marks from a torqued bolt.

 

[Longtimegone]

Still a nice head. Here's the only one I've seen offered recently, and yours looks better to me.

NORTON COMMANDO MOTORCYCLE DUNSTALL CYLINDER HEAD 810 BIG BORE 1970S RACING | eBay

Paul Dunstall Cylinder Head to be used with the 810 Big Bore Cylinder Barrel. Suitable for use on 750cc Norton Commando models. Head has large inlet valves and inlet ports, bronze valve seats, squish band machined away, reshaped inlet valve angle and reshaped exhaust ports.

www.ebay.com

 

[JACKYBOY]

Still a nice head. Here's the only one I've seen offered recently, and yours looks better to me.

NORTON COMMANDO MOTORCYCLE DUNSTALL CYLINDER HEAD 810 BIG BORE 1970S RACING | eBay

Paul Dunstall Cylinder Head to be used with the 810 Big Bore Cylinder Barrel. Suitable for use on 750cc Norton Commando models. Head has large inlet valves and inlet ports, bronze valve seats, squish band machined away, reshaped inlet valve angle and reshaped exhaust ports.

www.ebay.com

Thanks, not sure if i should reassemble before listing. I disassembled for vapor blasting

 

[ILLF8ED]

I purchased complete dunstall 810 head from Alex Singleton of motorcycles unlimited , Corte Madera CA. somewhere around 1978,79,80. The head was is in the parts showroom and was sold to me as new. complete with valves, springs. cups , keepers, spindles etc. I bought it for a project i had: A 1971 commando 750 that already had many dunstall parts minus the engine. The bike was stolen before i could complete it but I hung to this for all these years. So is this considered NOS?? Or technically aftermarket? Opinions would be appreciated, Im considering putting it on ebay.

I’m unfamiliar with the modifications Dunstall did on heads for the 810. The photo you post of the rockers seem to be standard, not lightened and polished per Dunstall’s book.

 

[concours]

Looks like carbon in the spark plug holes to me.
Missed by the glass bead (or imported walnut shells, or...) blasting operation

I'd RUN away from someone claiming this is New Old Stock.

No offense intended O.P., just half a century of horse trading skills.

GLWS

 

[JACKYBOY]

Looks like carbon in the spark plug holes to me.
Missed by the glass bead (or imported walnut shells, or...) blasting operation

I'd RUN away from someone claiming this is New Old Stock.

No offense intended O.P., just half a century of horse trading skills.

GLWS
View attachment 101981View attachment 101983View attachment 101982

I would agree as far as new old stock. as I stated above "Ive gone from Nos to: new, to like new!" due to the mounting bolt indentations alone.
Looking into the spark plug holes my initial reaction was that.. its just shadow from the photo. But it does looks more like carbon.
I was nineteen at the time ( Im 62 now) when Alex sold me this. And quite honestly it looked very much as it does now, as was then . other than the vapor blast treatment .. https://carpyscaferacers.com/shop/shop-our-store/services/vapor-blasting/ highly reccomend these peeps. (walnut shell....um no)

No offense taken by the way. I came to this board to ask for opinions one and all for the experience of others who may have more insite than I. identifying and selling this part, for me, isnt just about money. really. Ive dragged this around for years, not able to let it go.

I for sure took Alex for his word but If I had to describe him it would be an .. intense.. salesman and Ill leave it at that.

I purchased my 1971 commando when i was 18 years old with a dunstall wet dream. At that time I already had (AND STILL DO) 1965 bsa lightning rocket, I later aquired a 1968 bonneville t120r when i was 20 (still have as well ) Ive had countless bikes in between. (all gone now). So what it sells for ..to me, Im a million miles past the money or misrepresenting.

How many of you have hung on to your bikes ( and parts) for 40 plus years? just curious. Horse salesman. ..no.

British bikes..In my blood man.

 

[concours]

 

[JACKYBOY]

View attachment 101993

Thanks for that. Well put.

 

[Fast Eddie]

I agree, selling this as NOS does not seem correct.

I think you have to label it as ‘used‘ and describe it something like: “purchased in the 70s, this head was refurbished and modified by Dunstall to his 810 spec and has not been fitted to a motorcycle since” followed by details of port sizes and other specs.

JMO.

 

[JACKYBOY]

I agree, selling this as NOS does not seem correct.

I think you have to label it as ‘used‘ and describe it something like: “purchased in the 70s, this head was refurbished and modified by Dunstall to his 810 spec and has not been fitted to a motorcycle since” followed by details of port sizes and other specs.

JMO.

Thanks, This seems like the best thing to do. I appreciate your thoughts.

 

[Bruce MacGregor]

Thanks, not sure if i should reassemble before listing. I disassembled for vapor blasting

Hi, If it is the big valve Dunstal head , It is was the best increase in power that I ever did with my Nortons ,except for modifying a a Drouin.
I ran an 11.2 1/4 mile @ New England Speed way! on an 810 back in The 90's with that head.
Not to shabby against the 1000 cc Kows.
Bruce PS: Valves from a certain BMW car fit right in, back in the day !
Bruce