Cams

lwmcd1 · Nov 24, 2019

I've heard that there was a bad batch of cam produced that were improperly heat treated.
Is there a way to determine if the one I have aquired is one of those?
The only markings I see are
T22/9
sa inside circle then a 2.
I believe it came out of a 750 Atlas.
It's going in my 74 850.
Thanks,
Larry

ILLF8ED · Nov 24, 2019

lwmcd1 said:
I've heard that there was a bad batch of cam produced that were improperly heat treated.
Is there a way to determine if the one I have aquired is one of those?
The only markings I see are
T22/9
sa inside circle then a 2.
I believe it came out of a 750 Atlas.
It's going in my 74 850.
Thanks,
Larry

Hi Larry,

The soft cams came in 850 Commandos. By the way an Atlas camshaft will not work in a ‘74 Commando as the tachometer drive is different.

lwmcd1 · Nov 25, 2019

Yep,
I just noticed that there is no tac drive on the one I have.
I've never had a tac that worked more than a few 1000 miles
so I don't bother with them anymore.
that being the case, can I use one without the tac drive or are there other issues?

comnoz · Nov 25, 2019

lwmcd1 said:
Yep,
I just noticed that there is no tac drive on the one I have.
I've never had a tac that worked more than a few 1000 miles
so I don't bother with them anymore.
that being the case, can I use one without the tac drive or are there other issues?

No place for an ignition

lwmcd1 · Nov 25, 2019

Oh well,
I'll just have to get the right one.
Thanks.

lwmcd1 · Nov 25, 2019

comnoz said:
No place for an ignition

YooHoo!
I bought a set of 4 for $45 off of eBay.
They looked to be in very good condition.
I only need one.
Anybody needing one should let me know.
I'll be happy to share. the good fortune

lazyeye6 · Nov 25, 2019

I'd like to hear how this turns out.

lwmcd1 · Nov 25, 2019

lazyeye6 said:
I'd like to hear how this turns out.

I'll let you know.
The photos seemed to indicate they were in good shape.
I'll know for sure when I get them.

lwmcd1 · Nov 25, 2019

illf8ed said:
Hi Larry,

The soft cams came in 850 Commandos. By the way an Atlas camshaft will not work in a ‘74 Commando as the tachometer drive is different.

All 850s or only certain ones?

maylar · Nov 25, 2019

lwmcd1 said:
All 850s or only certain ones?

August '74 MKII - about 35,000 miles:

lwmcd1 · Nov 25, 2019

Mine looks way worse than that.
I still don't understand why it was running so good.

comnoz · Nov 25, 2019

maylar said:
August '74 MKII - about 35,000 miles:

I would bet the follower was soft and caused that damage -not the cam.

If you still have it I will buy it and test it for hardness. Jim

comnoz · Nov 25, 2019

lwmcd1 said:
I'll let you know.
The photos seemed to indicate they were in good shape.
I'll know for sure when I get them.

If you would like to sell the extras I will buy them. They can have any amount of lobe damage but the bearing journals need to be good. I will use them as cores for rebuilding. Jim

lwmcd1 · Nov 27, 2019

comnoz said:
If you would like to sell the extras I will buy them. They can have any amount of lobe damage but the bearing journals need to be good. I will use them as cores for rebuilding. Jim

Sure,
I'll look at them when they arrive and let you know the condition.
They look very good in the photos but
I don't trust photos very much.
I would not try to sell anybody junk.
Especially fellow Norton enthusiasts.
They should be in in a couple of more days.

lwmcd1 · Nov 27, 2019

Jim,
I also have a boatload of other Norton parts.
Also, 3 sets of BSA cases A10.
And a few Misc Triumph parts.
At's all just taking up space that
I don't have.
I'll try to upload some photos if I can figure out how.
Well shoot, I can't figure out how to upload photos.

comnoz · Nov 27, 2019

You would need a photo hosting site to upload photos unless you are a paid member here.

lwmcd1 · Nov 28, 2019

comnoz said:
You would need a photo hosting site to upload photos unless you are a paid member here.

I'll look into a hosting site though it may be beyond my skills with a pc.
By the way, what would it cost to have one of these cams properly hardened for my use?
Also, I have the one from the atlas if you think you can use it also.

Bernhard · Nov 28, 2019

9

lwmcd1 said:
I've heard that there was a bad batch of cam produced that were improperly heat treated. I believe it came out of a 750 Atlas.
It's going in my 74 850.
Thanks, Larry

You should have been in Paul Dunstalls shop in Well Hall Rd when he was having a clear out, there were at least race cams there that had the cam lobes completely worn away much worse than in p 9 – they were just scrap.

I would advise you to get the cams hardness treated, but this will not give you any information as to if it has been double hardness treated.

lwmcd1 · Nov 28, 2019

I don't know if this worked or not.
If it did this is just some of what I have.
I'm not so good at this.
https://ibb.co/hLc3rcz
https://ibb.co/thSCXpv
https://ibb.co/ckzXy44
https://ibb.co/02zZxhZ
https://ibb.co/M2vVgXS
https://ibb.co/FBQ41YV
https://ibb.co/syYW5qF
https://ibb.co/LQ0sdJ2
https://ibb.co/dpQ6Cnj
https://ibb.co/2dPDDrr
https://ibb.co/0KXbB4x
https://ibb.co/LnGFHqS
https://ibb.co/6WV2nw9
https://ibb.co/1mtvxBz
https://ibb.co/yFsJSLs
https://ibb.co/tPRZDGn
https://ibb.co/n67DwjV
https://ibb.co/8skFn5d

MexicoMike · Nov 28, 2019

TBH, I've always attributed cam wear to improper break-in though I admit I've seen plenty of statements about "soft cams," including those from cam suppliers so clearly, it happens. But I still wonder if cam break-in doesn't play the major role, caused by wrong assembly lube and/or incorrect break-in after the engine is running.

I've often wondered what the factory "break-in" method was - if any.

If there was none, just engine assembly, then the cam break-in was just 'however' the purchaser first rode the bike! The "break-in" specified in an owners manual is not what is needed for proper cam break-in.

Cams

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