Author Topic: New cam followers  (Read 1633 times)

Online ironhead

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Re: New cam followers
« Reply #30 on: 19.03. 2019 02:44 »
G'day,
Been pondering this cam follower hardness thing for a while now. :-\ Has anybody given an original un-molested follower the file test? I ask this because I have done this myself on 4 sets of original slightly worn ones on the un-worn part and all took a mark, not glass hard like the B&M engines as I expected. ( same with the cams)
I seem to remember reading somewhere that some cam & follower materials are not "glass hard" but made from a tough alloy steel. Does anyone know what material BSA made there A10/7 cam & followers from?
I know Notruns made there's from a low carbon case hardening steel & were very hard until someone re-ground them & didn't re-case harden properly (& subsequently only lasted a few weeks) .
SA

Offline Swarfcut

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Re: New cam followers
« Reply #31 on: 19.03. 2019 08:18 »
   Never had the courage to do this, but in the past have stoned small grooves and scuffs from cam lobes.
  Back in the day, Ford Pinto engines suffered from cam and follower wear. The followers always wore more, and if you were aware of a problem, it was an easy fix if you caught it early. The expensive cure was a new cam and followers, but for European Engines the cam came out through the back of the head, so it was head off, or engine out, or a hole in the bulkhead.  The cheapskate cure was a new set of  followers and removal of the wear ridges by hand stoning the cam in situ. A new, clean and free flowing oil supply rail completed the job, and you were back on the road for a good while. The design was different for US motors, the cam came out through the front.
 The performance difference after this codge was marginal, but the motors were restored to smooth unobtrusive running, even for a Ford. Remember these were real cheap clunkers, by the time I got them, and a noisy cam was a good bargaining chip when negotiating the deal.

   The metallurgy was fine, failure was all down to extended oil changes and blocking of the oil supply rail with carbonised oil. 

   Wear starts as straight line across the follower, as the greatest load is always concentrated in one place. Once through the hardening, its like a pothole....clunk clunk, getting bigger and deeper. On the cam, the contact load is spread over a larger area and maximum load only occurs on the toe for a short time in comparison, hence the differing rates of wear.

  I do not know if cams and followers are hardened to identical standards..any cam grinders on the forum?

 Swarfy

Offline bikerbob

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Re: New cam followers
« Reply #32 on: 19.03. 2019 19:15 »
Over 20 years ago when I restored my first 1957 A10  I polished out some marks on the cam followers but when I got the bike on the road they only lasted a few months I took them out and took them to a Guy who was giving me help and advice he said that what I had done was polish through the hardened layer on the surface of the followers thus exposing the softer metal underneath, he sent them away for me and they  were built up and reprofiled they were still on the bike when I sold it 16 years later.  So rather than buy new ones which could be sub standard if I was faced with worn followers I would look to having the originals rebuilt and reprofiled assuming that I coould find a company to do it.

Online berger

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Re: New cam followers
« Reply #33 on: 19.03. 2019 19:36 »
in the shed today- not the pub, so i got a smooth file and ran it over a ball race in several places , under a decent magnifying glass I could see little scratches but couldn't dig the file in. then I got some old followers  and did the same in several places including the inside slots. I got the same result, then on a part worn camshaft , by worn I mean about 4thou worn and could just dig the file in on the worn lobes using a lot of force but not on the shaft, only got scratches there. anyway if you've got cams or followers that a file doesn't glide over like on a ball race you might as well scream and throw them over your shoulder *pull hair out*

Offline chaterlea25

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Re: New cam followers
« Reply #34 on: 19.03. 2019 20:16 »
Hi All,
My SR has rebuilt stellite faced followers fitted , this was done back in 94/5 by SRM
They have been fine,
On the last A10 I built about 3 years ago I got some new followers, again they were stellite faced
I polished up the cam surfaces with a fine hone stone

A current engine on the bench is a BSA 350 from 1924, the followers are a bit manky *eek*
The plan is to regirind the profile and test for hardness, then make a decision as to "what to do next" if they are soft

Works for me
John
1961 Super Rocket
1963 RGS (ongoing)

Online berger

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Re: New cam followers
« Reply #35 on: 19.03. 2019 23:52 »
stellite is only the trade name but the mix of chrome alloys is a very good anti wear surface, just like platinum tipped points on spitfires , treated my maggy to a set of platinum tipped points, but going back to the dimple looking marked followers I don't think they are any good for any engine

Online Bsareg

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Re: New cam followers
« Reply #36 on: 20.03. 2019 00:36 »
I bought some rods marked Stellite and used one on my fury rockers. Seemed to flow like a braze using brazing flux. I was surprised how easy it was to profile (thought it would be much harder) and didn't have much hope of success, but in ten years have had to further problems. Perhaps Stellite work hardens in use ?
C11,B40,B44 Victor,A10,RGS,M21,Rocket3,REBSA

Online berger

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Re: New cam followers
« Reply #37 on: 20.03. 2019 01:27 »
never known of it work hardening like some stainless does, but it holds its properties at high temperature as in your welding , did you grind it for the finish off, it has a few properties like chromium and cobalt  including a bit of carbon and is very good anti wear material *good3* been around for donky's years and years and many more years

Offline BSA_54A10

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Re: New cam followers
« Reply #38 on: 20.03. 2019 09:10 »
Hi All,
My SR has rebuilt stellite faced followers fitted , this was done back in 94/5 by SRM
They have been fine,
On the last A10 I built about 3 years ago I got some new followers, again they were stellite faced
I polished up the cam surfaces with a fine hone stone

A current engine on the bench is a BSA 350 from 1924, the followers are a bit manky *eek*
The plan is to regirind the profile and test for hardness, then make a decision as to "what to do next" if they are soft

Works for me
John

So the next Cannonball attempt will be on a model L will it ?
OHV or SV ?
Bike Beesa
Trevor

Offline chaterlea25

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Re: New cam followers
« Reply #39 on: 20.03. 2019 13:04 »
Hi Trevor,
Its an ohv
I bought it as a rough runner a few years ago
Again it's been a long road to repair before restoring it
There's a couple in the Czech republic that make fantastic replica parts which has been a great help

As for the Cannonball 2020 ???
I do not know if my "sponsor" is up to trying it again

John
1961 Super Rocket
1963 RGS (ongoing)

Offline BSA_54A10

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Re: New cam followers
« Reply #40 on: 21.03. 2019 07:12 »
Hi Trevor,
Its an ohv
I bought it as a rough runner a few years ago
Again it's been a long road to repair before restoring it
There's a couple in the Czech republic that make fantastic replica parts which has been a great help

As for the Cannonball 2020 ???
I do not know if my "sponsor" is up to trying it again

John

That's interesting.
The landlord has a pair of L's one of each kind ( sloper excluded ) and is looking for a few parts, and a tank for the SV in particular.
Bike Beesa
Trevor

Offline chaterlea25

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Re: New cam followers
« Reply #41 on: 21.03. 2019 12:26 »
Hi Trevor,
There are at least 3 different types of
Flat tank for the L models
Jules Dassen in Holland has had a few replica tanks made, a friend bought one but it did  not fit his 24 at all!!!
And the 27 has a much more sloped back end
Again reference to the parts book needed

John
1961 Super Rocket
1963 RGS (ongoing)

Offline Scott and Jay

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Re: New cam followers
« Reply #42 on: 22.03. 2019 05:00 »
About the cam followers, all I can say is I bought a new set back in 2017 - because our engineer advised my old ones were too worn. I bought them from British Spares, Austria - because they said theirs were stellite-tipped. Our engineer said "they weren't" but did the hardness test - with his set of little files of different hardness. They passed. That's about 3.5k miles ago. No sign of wearing. My tappets don't get looser (more the reverse, occasionally). I just hope I've been lucky with these followers, then.  They were too tight at first, and he fettled them to a good sliding fit, also. I also use Penrite Enduro - because of its high zinc content. Our engineer was particular about the zinc, necessary for preventing cam-follower wear..

Offline BSA_54A10

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Re: New cam followers
« Reply #43 on: 22.03. 2019 07:36 »
Hi Trevor,
There are at least 3 different types of
Flat tank for the L models
Jules Dassen in Holland has had a few replica tanks made, a friend bought one but it did  not fit his 24 at all!!!
And the 27 has a much more sloped back end
Again reference to the parts book needed

John

Yes have already found that one out.
One thank s good the other is a blob of fiberglass with some original fittings in almost the right places.
Bike Beesa
Trevor

Online barry2

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Re: New cam followers
« Reply #44 on: 23.03. 2019 01:45 »
Hi Brit
I'm going w/- Swarf on this one, about  50 years ago we did an engine up (S/rocket) and were given the wrong head parts at the motorbike parts shop, I think it was the valves , they had the collet grooves in a different ( lower ) position and springs were binding and that wore the follower's out in about a week
Barry
WA