BSA lifter cracked stellite ...

The BSA cam followers I have in my Commando appear to have suffered a little. There is a mark in the centre which demonstrates evidence of valve float I believe, they could be re-ground and I could add a shim or 2 under the spring to increase the tension.

But, under a magnifying glass, the faces of the stellite pads are cracked, its hard to describe, but looks almost Iike a snake skin pattern of very fine cracks.

Is this common?

Re: BSA lifter cracked satellite

Satellite ?

Good job you caught it in time, isn't it.
Sounds like they don't stand up too well to all that pounding.

Back to the drawing board - or find a better welder ?

Re: BSA lifter cracked satellite

Rohan said:

Satellite ?

Good job you caught it in time, isn't it.
Sounds like they don't stand up too well to all that pounding.

Back to the drawing board - or find a better welder ?

Click to expand...

Oops... Have now corrected the title!

Just to be clear, its the cam followers I'm referring to (BSA ones). The stellite welded cam (JS1) still looks like new, which is fortunate!

Yes we realise that.

What does Jim say about the stellite welding on the BSA lifters.
If it was applied too thinly, it might get a rough time.

Is it only one with a problem, or all of them ?

Just speculating but....... I know that quenching stellite can cause micro-cracks.
Maybe the issue is heat related instead of valve float.

is it just one follower or all of them?

Rohan said:

Yes we realise that.

What does Jim say about the stellite welding on the BSA lifters.
If it was applied too thinly, it might get a rough time.

Is it only one with a problem, or all of them ?

Click to expand...

I have seen that before - more often than you would think. Its weird but I have never seen it cause a problem. It shows up when resurfacing them and it appears to be imperfections in the stellite. Sometimes you see oil weep from them from what appears to be fine fractures. Sometimes you see oil weeping from sides between the stellite and the steel when it get hot during resurfacing. Even so I have never seen one fail and I have seen a lot of them. The integrity of the brazing between the stellite and the steel is what is most important (they are furnace brazed).

New BSA lifters are available now from SRM at a price and I have New original lifters available. But the new original old stock lifters are probably the same quality as the Original stock Norton lifters (same brazing process and materials). The BSA lifters I have heard of failing were in extremely High RRM ultra short stroke 500cc motors turning around 10,000 RPM when the stellite fell off. Of the various English bike lifters - the BSA A65 type are the most reliable.

The mark or line in the middle is common wear and you see it on BSA lifters with time on them. And I have seen the fine cracks on high mileage lifters that were worn but still going and going. But I recommend that you replace it - especially since you take it on the track.

Mark mentions above that quenching stellite can cause micro cracks. This is probably something that happened way back when BSA made them.

jseng1 said:

Rohan said:

Yes we realise that.

What does Jim say about the stellite welding on the BSA lifters.
If it was applied too thinly, it might get a rough time.

Is it only one with a problem, or all of them ?

Click to expand...

I have seen that before - more often than you would think. Its weird but I have never seen it cause a problem. It shows up when resurfacing them and it appears to be imperfections in the stellite. Sometimes you see oil weep from them from what appears to be fine fractures. Sometimes you see oil weeping from sides between the stellite and the steel when it get hot during resurfacing. Even so I have never seen one fail and I have seen a lot of them. The integrity of the brazing between the stellite and the steel is what is most important (they are furnace brazed).

New BSA lifters are available now from SRM at a price and I have New original lifters available. But the new original old stock lifters are probably the same quality as the Original stock Norton lifters (same brazing process and materials). The BSA lifters I have heard of failing were in extremely High RRM ultra short stroke 500cc motors turning around 10,000 RPM when the stellite fell off. Of the various English bike lifters - the BSA A65 type are the most reliable.

The mark or line in the middle is common wear and you see it on BSA lifters with time on them. And I have seen the fine cracks on high mileage lifters that were worn but still going and going. But I recommend that you replace it - especially since you take it on the track.

Click to expand...

Thanks Jim. I'll talk to SRM, have you seen their lifters? If so, any comments?

Any regarding the wear marks, I'm using Redline oil which should be amongst the best thing for such lifters.

What about moving to a modern castor based R? Would this be a step forwards... or backwards...?

Fast Eddie said:

jseng1 said:

Rohan said:

Yes we realise that.

What does Jim say about the stellite welding on the BSA lifters.
If it was applied too thinly, it might get a rough time.

Is it only one with a problem, or all of them ?

Click to expand...

I have seen that before - more often than you would think. Its weird but I have never seen it cause a problem. It shows up when resurfacing them and it appears to be imperfections in the stellite. Sometimes you see oil weep from them from what appears to be fine fractures. Sometimes you see oil weeping from sides between the stellite and the steel when it get hot during resurfacing. Even so I have never seen one fail and I have seen a lot of them. The integrity of the brazing between the stellite and the steel is what is most important (they are furnace brazed).

New BSA lifters are available now from SRM at a price and I have New original lifters available. But the new original old stock lifters are probably the same quality as the Original stock Norton lifters (same brazing process and materials). The BSA lifters I have heard of failing were in extremely High RRM ultra short stroke 500cc motors turning around 10,000 RPM when the stellite fell off. Of the various English bike lifters - the BSA A65 type are the most reliable.

The mark or line in the middle is common wear and you see it on BSA lifters with time on them. And I have seen the fine cracks on high mileage lifters that were worn but still going and going. But I recommend that you replace it - especially since you take it on the track.

Click to expand...

Thanks Jim. I'll talk to SRM, have you seen their lifters? If so, any comments?

Any regarding the wear marks, I'm using Redline oil which should be amongst the best thing for such lifters.

What about moving to a modern castor based R? Would this be a step forwards... or backwards...?

Click to expand...

I am keen on the SRM lifters but don't know anymore than you. I know they have done some testing. They tried DLC coated steel but that did not work for lifters. So they went back to the original material but I would think and hope that they are paying attention to quality for todays high expectations. They are expensive and I don't think they have cut any corners.

Yes I recommend Castor R. You see it used by the highly stressed speedway bikes. Minnovation uses it in their singles and many Manx Nortons use it. The HD XR750 dirt trackers use it and there have been reports of pistons scuffing with screaming dirt trackers using synthetic oil. The Dave Watson 1000 Norton ridden by Gary Thwaites dominated the UK classic racing scene in 2012 and showed no bore wear or cam wear ("no wear at all") after a season. And this is after they had "severe" bore wear with synthetic oil and heavier longer pistons. The problem is that you have to completely clean the motor, oil lines, oil tank, crank and everything that might have some leftover oil or it will gel (I don't know for sure about synthetic oil mixing with Castor R). Then you have to drain it often and its hard to remove from the cases at tear down (I heard that boiling in antifreeze works). But to have no wear after a season sounds hard to resist. You won't know for sure until you run your motor again the same amount of time and compare the lifters for wear between Redline and Castor R. Then tell us all about it.

Nigel, you mean like this?
Not a very clear picture sorry, we put it down to valve bounce, I changed from Redline oil to Joe Gibbs (Driven) to suit flat tappet motors
Regards Mike

Here's a well used one out of an old street BSA. You can see the wear line. You see the same line on flat lifters and it can be worse because flat lifter cams have pointier lobes. All sliding lifters have this problem. The only way to get away from this is to go to roller lifters.



I'm going to repeat what Mark said.

Mark said:

Just speculating but....... I know that quenching stellite can cause micro-cracks.
Maybe the issue is heat related instead of valve float....

Click to expand...

The snake skin pattern of stellite micro cracks Fast Eddie sees under magnification were probably there when they were first made by BSA. Even so - I've never saw one fail when I worked at a BSA shop in the late 1960s/early 1970s and none of my customers has ever reported a stellite pad coming loose.

I've seen the same snakeskin pattern on every stock Commando lifter I've resurfaced (on a valve refacing machine). It disappears immediately with a little bit of final finishing with fine grit paper on a surface plate. I've always wondered what causes it. Every lifter I've resurfaced has shown that pattern, so I think it is just some property of Stellite that shows up under grinding. I've never had any of the resurfaced lifters fail. I've only ever had one stock lifter fail, when the Stellite pad came off in a short stroke 750 race bike.

Ken

In the picture of one of the lifters the area that the cam has not run on doesn't seem to have the "snakeskin" pattern. It reminds me of the pattern you get on a surface grinder (normally because you are over doing it) is it possible that its just made by effect of cam rubbing the surface. Has one tried any form of crack detection on them?

Mark said:

Just speculating but....... I know that quenching stellite can cause micro-cracks.
Maybe the issue is heat related instead of valve float.

Click to expand...

I guess I should edit this post to read microstructures instead of micro-cracks.
The snake skin look is caused by the crystals growing as a result of hardening. (recrystallization)

FWIW:
I could be completely wrong...... I ain't no metallurgist but I kinda remember taking a couple of classes in college.

The surface of stellite when ground does look like it is covered with tiny cracks - this is normal, differing grades of stellite have slightly different patterns. Don't worry about it, as far as I'm aware the actual stellite tip has never cracked up and failed.

Madnorton said:

The surface of stellite when ground does look like it is covered with tiny cracks - this is normal, differing grades of stellite have slightly different patterns. Don't worry about it, as far as I'm aware the actual stellite tip has never cracked up and failed.

Click to expand...

The RVI parts I worked on required Stellite weld overlay on 304L SST, we would L.P. check for cracks. It may be of use in this case :idea:
http://www.dynaweld.com.au/flaw-detecti ... ystem.html

Yes, if built up of weld, but stellite can be cast. In this case other than a casting flaw which should be identified at an early stage and thus re-cycled in the melting pot, cast ones in use from my and jseng1 experience, never prematurely fail only suffer wear marks after some serious miles.

Madnorton said:

Yes, if built up of weld, but stellite can be cast. In this case other than a casting flaw which should be identified at an early stage and thus re-cycled in the melting pot, cast ones in use from my and jseng1 experience, never prematurely fail only suffer wear marks after some serious miles.

Click to expand...

There have been several cases of the stock lifter, which has a cast Stellite pad brazed on, not a weld buildup, failing. I've had one of them fail and seriously damage an engine. It's possible some of the failures can be attributed to the braze join, not the Stellite material, failing, but in my case, part of the Stellite pad was still attached to the lifter, so I'm pretty sure the pad itself failed.

FWIW I've seen at least two lifters that had to be discarded after failing crack testing, but from cracks in the body, not the Stellite base. I've had dozens of lifters crack tested, and never seen a crack in the Stellite base.

Ken

BSA and Norton cam followers had the stellite working surfaces attached using a high frequency brazing technique. Only a few minutes ago whilst refreshing my memories talking to an ex BSA factory Gent he suddenly remembered the name of the person who ran the high frequency brazing department.....he then wondered why he should of had the name spring into his mind as he nad not thought of it since he was one of the last people to leave the factory after completing the last batch of B50s produced. Somewhere either in the loft or garage are a few new radiused 'lump' s of stellite used for Norton followers I must of picked up at one time somewhere in Birmingham thinking they might be useful one day.....40 plus years later and they still have not been useful......wonder where they are??

Now I can understand why people would think of using A65 cam followers in Nortons to save valve train weight / mass because an A65 follower weighs approx 39 grms and a Norton one (flat and radiused) approx 75grms but I cannot understand why anyone would do so. Mr Hele did not do so on his special 500 Domirace motors..he used lighter special Norton ones and did so because Norton cams require followers greater in working / contact length than A65 ones IF they are to work CORRECTLY. I even thought of (but didnt) using A65 followers in the late 80s when playing with a short stroke (68 x 68) 500 Dommy and that motor was pulling over 8,000 around the I.O.M without valve bounce occuring .....mind you the handlebars were apparently about 8 inches in diameter due to the vibes ...so the rider later told me upon his return.

A FEW FACTS.........
The radiused A65 followers were DESIGNED for use with the cams employed by BSA at the time. The total length of the face of an A65 follower is approx 0.650 inch and the length the cam works on(the wipe length) is shown to be approx 0.580 inch. Thus the cam does NOT contact the total length of the face of the follower. NOW LOOK AT THE FACES OF THE FOLLOWERS SHOWN IN THE POST........
I have two second hand Norton followers in front of me, one flat and one radiused. The length of the face of the flat follower is approx 0.940 inches and the cam has wiped a length of approx 0.840 inches leaving approx 50 odd thou unused at each end.The length of the face of the radiused follower is approx 0.890 inch and the wipe length made by the cam is approx 0.700 inch leaving 0.095 inch unused at each end.

I cannot possibly see how one can employ A65 followers with Norton cams..not unless you want the cam to be trying to dig into the side of the follower over part of its rotation probably putting a high side load on the follower........Oh I know people do it..a friend used to manufacture Norton alloy barrels using them and convert peoples std barrels to take them.... but I dont think he did it for long!!

As for the wear mark in the middle of the working area of the followers they all have it.....surely its the point where the only point of the cam in contact with the follower is the peak of the cam lobe and also the point where the valve spring is fully compressed putting the maximum load on to the follower.......small area and maximum load = most wear.

Another point possibly worth remembering is that BSA sensibly ran the cam behind the barrel allowing max cooling air to the barrel rather than masking part of the barrel AND they ran the cam in an oil bath ensuring good cooling lubrication which is something Mr Hopwood designed into his original Dommy motors to give good lubrication but which the exspurts later in charge totally removed resulting in premature cam failures...probably to increase dramatically sales of cams and followers!!

One day I will tell the tale of the first batch of brand new Commandos sent to the USA which when unpacked were found to have frames with broken mai n spines......Oh joy.....The proverbial hit the fan back in the factory but when you employ someone to design a frame with little of no experience of doing such things..... and who failed to FIRST seek advice from experts before doing so......If you want to see a picture of one see the book THE RACING MOTORCYCLE Volume 2 Page 147. John Bradbury. ISBN 0 9512929 3 5.
As for the tale of the Italian made Commando frames....

NO SPELL OR GRAMMER CHECKS DONE....

Another good read Mr Leadbeater, one point you might reflect on is that all conversation on this forum regarding the use of BSA cam followers in Nortons, is in the context of using them with specially made dedicated camshaft, made to suit the radius of the BSA followers. To my knowledge at least, no one has ever discussed using BSA followers with Norton cams.

J. M. Leadbeater said:

One day I will tell the tale of the first batch of brand new Commandos sent to the USA which when unpacked were found to have frames with broken mai n spines......
As for the tale of the Italian made Commando frames....

Click to expand...

The subject has cropped up in several previous discussions (some of which you have contributed to) so I think perhaps we can do without, thanks. That goes for Italian frames too.