Camshaft ID

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Are you certain they we combat cams. Many of the combat engines were rebuilt with standard Commando cams which would have scrolled bearing area. The original combat cams shown in the parts book dwg as not scrolled and all the manuals warn not to use unscrolled camshafts with unscrolled bushes. The lobes on a combat when side by side with a standard Commando camshaft are very appearent.

Parts books were made before production commences. Same with advertising. Things changes between prototypes and production.

It seems there are both scrolled and plain 2S cams out there. And even aftermarket ones. Anyone want to sleuth and find out the truth?
 
Looks like it'll be a while before you're sweating a search for parts.
 
Early 750 on the left, and late 750 on the right, not 850 as the DS scroll is not correct for '70's made 850 cam.

What might this cam be ?

No wonder when I push it into the 850 D/S cam bush there is a pressure build up enough to make it want to pop out with the pressure.

It has that machined section between the lobes and not sure where I got it, I did buy the con rods and camshaft from a '200 mile Combat some years ago but do not remember if this is that camshaft.

Camshaft ID


Camshaft ID
 
If it has not been drilled internally to a depth where breather ring is then, 06.2608 prior to Drg Amend 6 at least, as this is when the scroll changed to break the end.
 
What might this cam be ?

No wonder when I push it into the 850 D/S cam bush there is a pressure build up enough to make it want to pop out with the pressure.

It has that machined section between the lobes and not sure where I got it, I did buy the con rods and camshaft from a '200 mile Combat some years ago but do not remember if this is that camshaft.

View attachment 10527

View attachment 10528

TW I would say yours is like a 06-1084 from an 73-74 850 if it has a 1S grind. Definitely not MKIII because the DS scrolling does not break out beyond the bush. The fully machined shaft is a modification as production cams were not like that. Also the intake and exhaust lobes have the same width makes it early. It may not be stock or old.
Camshaft ID

If you look at my pix anyone can see the wear from the split MKIII TS bushes on the bottom four 06-2808. Next those 06-2608 all have wider intake lobes. no sling ring or any prep for cam end breather.

Note the 5th up cam has no evidence of MKIII type cam bush wear, has the narrower intake lobes like early cams. no sling ring or any prep for cam end breather. This may be a earlier 06-2608 or regular 850? It is roughly fully machined. It does have DS oiler groove break out.

6th cam up has no DS oiler groove break out , or split cam bush wear evidence, or sling ring or timed breather prep.

Top cam is earliest in this pix, is a later 200000 cam, 1S grind, typical residual sling ring, early narrow intake lobes, but no further timing breather preparation i.e. disc drive notches or gun drilling/cross drilling in sling ring .

I think intelligent people should see the foolishness of call the 200000 series a "combat" without adding "tune" or "breather" (or both).

Sorry that I don't have a pile of papers/drawings, but the actual hardware I pulled out of the over 35 engines starting in 1988 tells volumes...I have this habit that eventually the parts get examined. It was part of both my professional career and hobby.

Aftershock:
Taking a further peek at the 5th cam up...the lobes are ex 1.22" and in 1.263"(corrected typo). This would hint at a 2S grind. with fully(rough) machined shaft and break out DS oiler groove is a new one for me... aftermarket? I will fully profile this cam and report back.
 
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TW I would say yours is like a 06-1084 from an 73-74 850 if it has a 1S grind. Definitely not MKIII because the DS scrolling does not break out beyond the bush. The fully machined shaft is a modification as production cams were not like that. Also the intake and exhaust lobes have the same width makes it early. It may not be stock or old.
Camshaft ID

If you look at my pix anyone can see the wear from the split MKIII TS bushes on the bottom five 06-2808. Next those 06-2608 all have wider intake lobes. no sling ring or any prep for cam end breather.

Note the 6th up cam has no evidence of MKIII type cam bush wear, has the narrower intake lobes like early cams. no sling ring or any prep for cam end breather. NO DS break out oil groove typical of all pre MKIII.

Top cam is earliest in this pix, is a later 200000 cam, 1S grind, typical residual sling ring, early narrow intake lobes, but no further timing breather preparation i.e. disc drive notches or gun drilling/cross drilling in sling ring .

I think intelligent people should see the foolishness of call the 200000 series a "combat" without adding "tune" or "breather" (or both).

Sorry that I don't have a pile of papers/drawings but the actual hardware I pulled out of the over 35 engines starting in 1988 tells volumes...I have this habit that eventually the parts get examined. It was part of both my professional career and hobby.

Camshaft ID



Do you have any information or examples of '850' or '850 Mk3' drive-side bushes, as, according to the parts books, 06-5425 is the later (850 Mk2 and Mk3) drive-side bush. The early '850' D/S bush is part 06-3021 and which appears to have been superseded by 065425.

Although not visible, presumably AN's 06.5425 bush has the oil hole?
https://andover-norton.co.uk/en/shop-details/16513/camshaft-bush-d-s-06-3021-
"06.5425 CAMSHAFT BUSH D/S (06.3021)".
 
Camshaft ID



Do you have any information or examples of '850' or '850 Mk3' drive-side bushes, as, according to the parts books, 06-5425 is the later (850 Mk2 and Mk3) drive-side bush. The early '850' D/S bush is part 06-3021 and which appears to have been superseded by 065425.

Although not visible, presumably AN's 06.5425 bush has the oil hole?
https://andover-norton.co.uk/en/shop-details/16513/camshaft-bush-d-s-06-3021-
"06.5425 CAMSHAFT BUSH D/S (06.3021)".

See this pix:
http://atlanticgreen.com/images/camID.jpg
Cam Bush from left to right is the
1. 20M3S thick wall bushes from I bought new at both Shenstone AN & BSA Regal AN . 06-7538/39
2. NOS from ex norton dealer 06-2600/01 and some take-outs/ I'll never use these except for wall of shame.
3. 1 new 1 take out 06-3021 w/hole 850 DS, source unk, Might have been fairspares/norvil before the war. You could spec real AN parts if desired, which I did on many occasions.
4. 2 NOS MKIII DS bushes 06-5425 with no holes. (will add them if used in regular 850) or as is for MKIII. Source unknown. Maybe from mid/late 90's
5. three 06-3020 TS 850 bush
6. Not seen- 06-5428 half TS bush MKIII- used several sets in various engines but currently out of inventory.

Will redo the cam ID's when enough time and add to my cam web page
 
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3. 1 new 1 take out 06-3021 w/hole 850 DS, source unk, Might have been fairspares/norvil before the war. You could spec real AN parts if desired, which I did on many occasions.
4. 2 NOS MKIII DS bushes 06-5425 with no holes. (will add them if used in regular 850) or as is for MKIII. Source unknown. Maybe from mid/late 90's

Thanks.
So 06-5425 (with hole) in the OldBritts line-up is in fact 06-3021 but which is now apparently sold as 06-5425.

Edit: Some of the 06-5425/06-3021 items offered for sale without hole appear to be Oilite. Is that normal (at least for 06-5425)?

https://boaspares.com/products/norton-camshaft-bush-nos
https://www.britbikes.co.uk/camshaf...o-850-mk2mk3---driveside---06-5425-1336-p.asp
 
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All the ones I do have, but not MKIII TS half bush, won't snap/tear if crushed in a vice like oillite sintered bronze.
I would have obsoleted 06-5425 and made that one NLA, and only kept 06-3021 w/hole in production.
One step forward two steps back.....
both of the listed urls show items I would not care to get.
 
I take it these undrilled D/S bushes are oil feed hole drilled after fitment.

I used the AN 06-5425 bush which is pre drilled with quite a large hole compared to the case drilling but maybe that is to have a small reservoir and for some leeway when pressing it home.

I only threw it away the other week but the bush I installed looked to be the same as what I had removed (Dec73 VIN)
The oddity (or not) was the cam lobes (Mk2a) were all fine but the T/S cam journal and cam bush were heavily corrugated.

Thanks for the reply DD.
 
I take it these undrilled D/S bushes are oil feed hole drilled after fitment.

As dynodave said, the undrilled D/S bush is for the 850 Mk3 (because the oil feed hole connects to the chamber at the outer end of the camshaft journal) therefore, the Mk3 bush had no oil hole and this was the original 06-5425 part.

I used the AN 06-5425 bush which is pre drilled with quite a large hole compared to the case drilling but maybe that is to have a small reservoir and for some leeway when pressing it home.

The original drilled 850 D/S bush appears to have been 06-3021 but is now sold under both 06-3021 and 06-5425 part numbers.
 
I see, more AN shenanigans.
You can be assured if they are one and the same bush the hole is hidden on the AN picture for whatever reason regarding both or either ( Mk1 2 3 850)

Without sounding to pedantic, if the two bushes are the same dimension but hole and no hole and had different part numbers they should have been left that way..... No doubt a generic AN part now to cover both model even if the added hole cost more money at production.

Why does AN for all their rabbiting on about the drawings keep trying to rewrite history.

Make sure to chamfer the back of the hole to avoid galling the bore in the engine case is all I can add.
 
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I see, more AN shenanigans.
You can be assured if it is the same bush the hole is hidden on the AN picture for whatever reason.

Also, 06-5425 (no hole) is the D/S bush listed in the 850 Mk2/2A supplement, so either it's wrong or the bush oil drilling was changed sometime during Mk2/2A production but early enough to be included in the parts supplement?

Something else of interest in the 2/2A supplement is that the timing side "camshaft bush" is the short 850 Mk3 part 06-5428 (x2).
 
Also, 06-5425 (no hole) is the D/S bush listed in the 850 Mk2/2A supplement, so either it's wrong or the bush oil drilling was changed sometime during Mk2/2A production but early enough to be included in the parts supplement?

Something else of interest in the 2/2A supplement is that the timing side "camshaft bush" is the short 850 Mk3 part 06-5428 (x2).

My Mk2a is probably to early in the piece (Dec73) to have any of those internal changes especially if the D/S oil feed hole position was moved further toward the primary.

My T/S was the one piece 3020? iirc but did get two of the Mk3 bushes which now sit unused (Post them to DD perhaps ?) as I replaced with what was removed as there were postings of the short bushes moving even though a thrust face on both sides seems like a good idea, no doubt why they were introduced.

#
The 850 bushes that are drilled look to have a large hole compared to what is in the engine case but that would aid alignment and also add a reservoir of sorts at the journal/scroll although a bevel at the inner ID might be better but hard to do in production. (Like a crank journal feed reversed)

I do not see what the problem was with the 750 cam bushes, the OD has a groove for the oil hole to feed in theory giving full circumference oil to the journal (perhaps intended for non scrolled journals originally) , the only down side is the contact area of the bush OD to engine case bore is reduced but they are wide bushes anyway... Change for changes sake ?

Edit.
Perhaps that 750 set up was for non scrolled journals (I do not know the history of the Atlas range) and with a scrolled cam the groove was drained to quickly verses the small feed hole in the case, when I put oil in the 850 feed hole and rotated the cam, the scroll drew the oil in very quickly,repeatedly. (Which made me wonder how my T/S bush was so worn beyond some form of oil starvation).. I admit to drilling the case feed holes slightly bigger along with a bigger bevel at the inlet side.

Camshaft ID
 
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My two 316xxx engines have 06-3021 in the DS and the bush and case drilled hole position is as expected: mid bush.

Engines out for an airing minus at least 6 more that are in bikes:
Camshaft ID


"I do not see what the problem was with the 750 cam bushes, the OD has a groove for the oil hole to feed in theory giving full circumference oil to the journal (perhaps intended for non scrolled journals originally) , the only down side is the contact area of the bush OD to engine case bore is reduced but they are wide bushes anyway... Change for changes sake ?"

Certainly not easy to figure why 1949 through the end of 20M3S they had thick wall bushes, then changed @ 200k with more changes to follow?
Certainly the thick wall bushes were easier to install and remove and probably never needed to be reamed.
I have yet to need to ream a cam bush...even the thin wall ones. But I don't use a sledge hammer technique to install them.

AGAIN... AN wake up: I would have obsoleted 06-5425 and made that one NLA, and only kept 06-3021 w/hole in production.
 
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https://www.rgmnorton.co.uk/dept/camshaft-followers_d0147.htm

which one do you prefer about the timing side oil lite or not....(065428 or 064997)....those I have the oil lite are closer in the tolerance and will not need reaming , the other one needs reaming , I had noticed that in the CBS part list they supply a ball to fit in the TS bush to size it , before using their tool for reaming the DS bush ........??

https://www.classicbritishspares.co...er-tool-set-cbs-0296-6t-5t-t120-t140-tr7-t110
 
AGAIN... AN wake up: I would have obsoleted 06-5425 and made that one NLA, and only kept 06-3021 w/hole in production.

That would certainly be the logical thing to do, or offer both bushes under the correct part numbers, but if the factory drawings and amendments don't match what was actually being produced at the time then no wonder it's a muddle.
 
Lab has it spot on.

06.3021 was drawn Sept '71 and has a hole it, by July '74 (3 amendments later the hole was removed, but it does not say which amendment removed the hole, due to the Norton love of tipex.

06.5425 was drawn Aug '73 and has always had the hole from the original drawing date.

It seems that by 1973, they forgot they had actually produced a bush with a hole in it and raised another drawing. The supersession and amendment list from NT has 06.3201 superseeded by 06.5425 - lets not confuse the picture anymore!!
 
06.3021 was drawn Sept '71 and has a hole it, by July '74 (3 amendments later the hole was removed, but it does not say which amendment removed the hole, due to the Norton love of tipex.

It seems that by 1973, they forgot they had actually produced a bush with a hole in it and raised another drawing. The supersession and amendment list from NT has 06.3201 superseeded by 06.5425 - lets not confuse the picture anymore!!

It still doesn't quite make sense if, as dynodave claims, the 850 Mk3 D/S bush didn't have the hole as bushes without a hole can't be 06-5425 (or 06-3201).
 
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