OEM Cam Follower Pad Separation Question

For those of us still running OEM (non-spigotted) cam followers there is a decision to be made as to whether or not to spend 417 USD on a new set. This doesn't include getting them tested for hardness, nor does it factor in the possibility that you might have to buy another pair if one is found lacking.

Is it possible that once a certain mileage is reached that the majority of failures will have occurred if the fault was a poor brazing joint? If so, how do we determine what that number/mileage is?

Just wondering,

Russ

"The luck of the draw"

I have owned my Norton since new has well over 160k miles and was a everyday ride till about 5 years ago, I am still running the stock lifters, yes they have been reground but they are still good, like GrandPaul has said its the luck of the draw, some have had problems and others haven't, my last motor I rebuilt for a mate one of his lifters had a big deep gouge in it and was beyond repair, so a new set was brought, bloody expensive fuc...., when I see used ones at swap meets or evilbay and if they are cheap I buy them have 4 sets now and they only have a few wear marks on them and be easy to resurface them.
So knowing how long they will last, how long is a piece of string, its anyones guess.

Ashley

Jim, your work is both meaningful and fascinating. It really looks like you're onto something with your asymmetrical cam design. I have to wonder if you've done or have considered working on other motorcycle and automotive applications. (Not that I or anyone on this forum would want to see your Norton efforts diluted!!!) I'm just thinking your eventual solution could be licensed for other applications and you could move up from McDonald's to Olive Garden.

Atlas,
I think you need to re-post this into Jim's thread here. https://www.accessnorton.com/NortonCommando/cam-and-follower-tests.25859/

Atlas Commando said:

Jim, your work is both meaningful and fascinating. It really looks like you're onto something with your asymmetrical cam design. I have to wonder if you've done or have considered working on other motorcycle and automotive applications. (Not that I or anyone on this forum would want to see your Norton efforts diluted!!!) I'm just thinking your eventual solution could be licensed for other applications and you could move up from McDonald's to Olive Garden.

Click to expand...

Regards,
Thomas

Atlas Commando said:

Jim, your work is both meaningful and fascinating. It really looks like you're onto something with your asymmetrical cam design. I have to wonder if you've done or have considered working on other motorcycle and automotive applications. (Not that I or anyone on this forum would want to see your Norton efforts diluted!!!) I'm just thinking your eventual solution could be licensed for other applications and you could move up from McDonald's to Olive Garden.

Click to expand...

Thanks, I have done a few high end projects for other bike concerns in the past.
I am more or less retired now and just having fun. More of a Coors tavern kind of guy...Jim

I started this thread because we were asked not to discuss this in the other cam follower thread.

So my question is serious. I realize it is the luck of the draw as to whether or not you got good stock followers. But doesn't it make some sense that if Ashman's followers were going to fail from a bad brazing job that they would have done it by now? So maybe at 160,000 miles they fail for another reason but I bet it isn't from the pad falling off. There must be a number somewhere lower than 160,000 at which we might consider our followers as good ones.

If the pad stays intact, what other failures are there that are associated with the part failing and not as collateral damage to some other catastrophe?

Russ,
Well knowing now, what we have recently discovered with hardness variations between Jim Comstock's thread and Fullauto's PW3 failure Thread. If I am going to rebuild an engine, then locate a hardness tester source. That would be my first test on both used and new followers. If I discovered one lobe going south, I would target that follower as suspect. I would then do a NDT using liquid Die penitrant. This would highlight and pull out any pinholes along the edges as well as incomplete bonding areas in the joint between the braze and stellite pad. If it bleeds then treat it as suspect. Not a perfect method but takes out some weeds. I will ask at work in our Metallurgical department what other cheap and dirty NDT method are available. An inspection microscope comes to mind.
https://ae01.alicdn.com/kf/HTB1obMQ...ion-Microscope-10MP-Camera-Windows-Mac-OS.jpg
Radiography testing is kind of going over the top and not cost effective for your new fresh rebuild. We just want a few tests to prevent a premature cam failure 20,000 miles down the open road.
Cheers,
Thomas

Loosing the follower pad on a Norton, BSA or Triumph has been a fairly rare happening as far back as I remember, but it does happen.

I ran the original followers for many years in my bike and never had one come apart.

Then I "upgraded" to BSA followers and lost a pad. It was actually a follower that had been used in my racebike for a long time. I resurfaced them and turned them around when I put them in my streetbike so they would wear on the other side. If I had not turned it around the unsupported half of the pad may have never cracked off.

Then I went to new followers and the luck of the draw got me again -this time with a soft pad.

Keep in mind that I went through a bucket full of beat up followers to find three that I could break off with a 3 foot bar and a good whack. Even though the welding was obviously not very good I would guess only one or two of them would have failed in use.

I used an ultrasonic tester to check cylinder liner thickness when I was doing diesel builds some years back. I would find it hard to imagine that it could find a lifter with a void in the weld -but I haven't tried it.

Radiography? Maybe, but it would take a pretty specialized unit I would think.

I always do a tap test. I know it's definitely not 100% sure, but it's a useful indication. Tap with a small steel bar on top of the stellite pad of each follower. The one with a loose or bad brazed pad will sound more dull.

Just to summarize for anyone searching for information on stock OEM followers when these discussions have been forgotten. Like next week.

All followers should be tested for hardness. High 50's to low 60's (58-62?) seems to be a good range as reported from the Comstock laboratory. A few degrees harder than the cam is desired. (Testing continues as of this date and more detailed information may emerge)

Spigotted followers have been reported to be a big improvement over the original flat brazed joint. (Spigots where introduced in the 1980's, some verification needed as to date)

Flat brazed joint followers should be examined for poor fit. A good brazing job leaves nothing but a fine line at the interface.

Road tested followers do apparently have an advantage over low mile followers in that they have proven themselves as far as the braze joint. The number of miles required to vet these followers is unkown/subjective.

Here is a quote from Comnoz in another thread: "So if the followers have significant miles on them and the cam has not failed because they were soft and they have not fallen apart -then I would not worry about them."

So it would seem that we can buy spigoted followers and test them for hardness, or verify the originals to the best of our abilities (including testing for hardness). This is my understanding of the current situation and may not reflect current thinking or philosophies of the Norton community, nor does it presume to offer information regarding other follower systems such as BSA or radiused followers of any kind, offer void where prohibited, may result in blindness, death or injury. If you have thoughts of suicide stop working on your Commando immediately and seek the advice of a bartender.

Nice summary rvich - have you considered a career in family counseling? All kidding aside, nice summary.

A quick and dirty way to a partial check for the bond quality interface between the tappet body and the hard face is to use a jewelers loop or geologist magnifier to closely examine the perimeter for partings.

rvich said:

Road tested followers do apparently have an advantage over low mile followers in that they have proven themselves as far as the braze joint. The number of miles required to vet these followers is unkown/subjective.

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The susceptibility of the brace joint to fatigue stress has not been clarified as yet. I would be careful fitting well used tappets just because they look nice and haven't failed yet.
Unfortunately these are highly loaded parts with a somewhat fragile composition.

-Knut

mdt-son said:

The susceptibility of the brace joint to fatigue stress has not been clarified as yet. I would be careful fitting well used tappets just because they look nice and haven't failed yet.
Unfortunately these are highly loaded parts with a somewhat fragile composition.

-Knut

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To illustrate....I lost the stellite on a '75 made follower....in '78! After the best part of 3 season racing. It had been out and inspected at least twice!

On the upside, the cam survived the experience and new followers dropped straight in!

proper oil filtration a factor?

ashman said:

I have owned my Norton since new has well over 160k miles and was a everyday ride till about 5 years ago, I am still running the stock lifters, yes they have been reground but they are still good, like GrandPaul has said its the luck of the draw, some have had problems and others haven't, my last motor I rebuilt for a mate one of his lifters had a big deep gouge in it and was beyond repair, so a new set was brought, bloody expensive fuc...., when I see used ones at swap meets or evilbay and if they are cheap I buy them have 4 sets now and they only have a few wear marks on them and be easy to resurface them.
So knowing how long they will last, how long is a piece of string, its anyones guess.

Ashley

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i was about to ask u to post your experience tx

Well my experience is I have had no problems with my stock lifters at all and I have owned my Norton for over 43 years now, when I rebuilt my motor back in the early 80s when I converted it to the Featherbed frame I got my stock cam built up and reground to Combat specs (2S profile) the lifters had wear marks on 2 lifters, I been lucky as I worked at a Tec College and had access to a full machine shop, we made a jig to hold 2 lifter and used a surface grider to reface them, to this day I am still using them, last rebuild 6 years ago they were still good, I am no longer working but still have the jig.
On my mate's Norton 1 lifter was so badly gouged was not worth machining but we decided was best to replace with new lifters, I have only rebuilt the bottom end as the head is still away getting a rebuild but I no longer have the motor as I got other projects on and got sick of waiting for my mate to get the parts, I installed the new lifters and was ready to put the cylinders back on, thats as far as I got with his motor, but he also replaced the cam with a new stock one.

Ashley