Current production Norton 961 Parts

OK , I don't remember that, He must have really lunched that engine ! I would like to hear from the NZ high performance guy. Just think all we could learn from him !
 
TonyA said:
The reason I bought the head was to replace mine if the valve guides get worn out like David C's did. David managed to get replacement guides somehow though so I would only be down for shorter while in that case. I don't like being down especially with this bike.
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Hello,

a new head is not necessary, Thiel Motorsport have improved valve guards and seats.
Ollie is overhauling a lot of heads every year.
A new head is not much better tha your old one. The seats are not 100% ok and the valve guards are to wide dor the valves. The seals are complete shit.

Kind Regards
Panetone
 
Got this response back today. When the time nears and if nobody is willing to send in a cylinder head, I’ll probably purchase a new one. At least there might be hope for power gains. Who would be a candidate to grind custom cams for the 961?
 

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Voodooo said:
Got this response back today. When the time nears and if nobody is willing to send in a cylinder head, I’ll probably purchase a new one. At least there might be hope for power gains. Who would be a candidate to grind custom cams for the 961?
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Talk to Ollie Thiel at Thiel Mortorsport in Germany, or if he doesn’t respond, talk to Panetone (above) and ask him to talk to Ollie !
 
OK , Thanks for checking. I will have a head , either a this new head or my removed original head after I install the new one.
 
TonyA said:
OK , Thanks for checking. I will have a head , either a this new head or my removed original head after I install the new one.
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Worth doing everything, upgrade wise, to the new head before fitting? Probably already in hand!
 
Voodooo said:
Got this response back today. When the time nears and if nobody is willing to send in a cylinder head, I’ll probably purchase a new one. At least there might be hope for power gains. Who would be a candidate to grind custom cams for the 961?
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OK , Thanks for checking. I will have a head , either a this new head or my removed original head after I install the new one.
 
Brilliant news and they won't have cash flow problems so very good news for all of us around the world. Another thing that really struck me on a friday factory tour at Norton Jan 2018, I asked Clem about ISO 9001:2015 quality standard and if the factory operated it. Was surprised that they had no formal system.

I hope they commit to suport for the 961's long term, means it is definately a keeper for me
 
AF1 doesn't really have much in their in-stock spares list, but here's hoping they work at stocking more. I bought $5K+ in parts from them in the past, and their service was great. At least they are still willing to order parts for customers.

Ken
 
speirmoor said:
In the latest Email from AF1
"Norton News: We are happy to report our first Norton spares order has been received!

Norton is officially back in business!!!

It'll be a long while before we see bikes imported to the US again, but we can support the existing owners with spare parts!"

AF1 Racing. Norton Motorcycles - Spare Parts

www.af1racing.com www.af1racing.com
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I am pretty happy right now , these cylinders and pistons measure right in service manual specs . I just got the head back from the machine shop and guides and stems are perfect .

Current production Norton 961 Parts


The valve lifter bores are mirror polished. I am including this because someone asked what the lifter keeper bolts were. You can see them at the bottom of the lifter bores , they stop the lifter from rotating in their bores .


Current production Norton 961 Parts


Cross hatch honing from Norton UK

Current production Norton 961 Parts



With a valve job from a trusted machine shop.

Current production Norton 961 Parts



Finally , A proper top end .
 
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TonyA said:
I am pretty happy right now , these cylinders and pistons measure right in service manual specs . I just got the head back from the machine shop and guides and stems are perfect .

Current production Norton 961 Parts


The valve lifter bores are mirror polished. I am including this because someone asked what the lifter keeper bolts were. You can see them at the bottom of the lifter bores , they stop the lifter from rotating in their bores .


Current production Norton 961 Parts


Cross hatch honing from Norton UK

Current production Norton 961 Parts



With a valve job from a trusted machine shop.

Current production Norton 961 Parts



Finally , A proper top end .
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Are the piston rings gapless or file fit?
Are the chambers CC measured by any chance?
 
TonyA said:
Not gapless rings. Norton OEM rings. Not CC’d. As they came from Norton .
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Is there a reason you’re replacing the cylinders, pistons, head etc?
Are you doing it for a rebuild and no performance gains?
 
Those parts all looks really nice. No signs of porosity etc, nice machining. Good to see.

I like the proper squish design of the bathtub combustion chamber. But I notice the step around the outside of the piston crown. That’s strange, it means that even if that step is gapped properly to the head to get a good squish, the rest of that squish area on the head is wasted. Ideally any recess in the piston should match the bathtub shape. Even more ideally, no recess is needed!

I’d look into what the CR would be with a flat top piston and a 0.040” gap. If you assume 1mm it makes it very easy to calculate the volume of that squish gap to add to the measured CCV to calculate CR.

As I’ve discovered on my 920 engine, a working squish allows a surprisingly high CR without issues. But you boys in the US who take long trips do have to factor in using low octane fuel when needed.
 
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Voodooo said:
Is there a reason you’re replacing the cylinders, pistons, head etc?
Are you doing it for a rebuild and no performance gains?
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Hello Voodoo , This was done to get to the bottom of my oil in air box issue . Lets use the 1oz. (30ml) per 1000 miles of riding as a minimum goal , and I will hope for better and I think that is achievable . My last test showed ~ (15 ml) in 300 miles at best . That is at a relatively steady 70 mph. As far as performance increase , if I get any I will take it . :)
 
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Fast Eddie said:
Those parts all looks really nice. No signs of porosity etc, nice machining. Good to see.

I like the proper squish design of the bathtub combustion chamber. But I notice the step around the outside of the piston crown. That’s strange, it means that even if that step is gapped properly to the head to get a good squish, the rest of that squish area on the head is wasted. Ideally any recess in the piston should match the bathtub shape. Even more ideally, no recess is needed!

I’d look into what the CR would be with a flat top piston and a 0.040” gap. If you assume 1mm it makes it very easy to calculated the volume of that squish gap to add to the measured CCV to calculate CR.

As I’ve discovered on my 920 engine, a working squish allows a surprisingly high CR without issues. But you boys in the US who take long trips do have to factor in using low octane fuel when needed.
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Hello FE , These are not high compression pistons , only what Norton UK supply me as OEM . Looking at Ollie Thiel's pistons , with no dish and what appear to be deeper valve pockets. Those would probably increase the CR hey ? Now that I have my cylinder bore measurment , I could email Ollie and discuss it suppose . I was worried about having the right setup for Nikasil cylinders .
 
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