BSA lifter cracked stellite ...

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Hi mr Leadbeater, as Fast Eddie pointed out, you need specially made camshaft with A 65 lifter.
The radius on the lifter itself change the lift curve.
Those specially made camshaft have more radius to restore the lift curve and also not to digging in.
Obvious to me and it has been discussed here alot in this forum

Sten
 
Chaps,

I contacted SRM (UK based BSA specialist) who now make and sell new A65 cam followers (as used on JS kits).

Interestingly, the stelleite pads on original cam followes were attached via induction braising, and as we know, pads have been known to come off of various makes of OEM follower.

The new SRM followers are made slighty differently as the stellite is built up by welding rather than relying on seperate braised on pads. This is the same process used to build up stellite faced cams, and as far as I am aware, provides a very robust finished product.

So I think I'll try some SRM followers and let y'all know how it goes!
 
Fast Eddie - thanks for the informative post. I hope you don't mind me saying though, but 'braising' is a cooking operation, whereas 'brazing' involves melting braze rods to join two or more pieces of metal together!
 
The Gentleman who ran the high frequency brazing dept at BSA was I believe one George Mills. A friend who was one of the last to leave BSA after helping machine and build the last batch of B50s suddenly remembered the Gents name and then spent the rest of the day wondering why the name should pop up in his brain after all that passage of time...... I told him it is a sign of serious old age......
I made a phone call yeaterday and learnt that for many years the stellite pads on Norton followers have been attached by a hearth copper brazing technique.
 
Paddy_SP said:
Fast Eddie - thanks for the informative post. I hope you don't mind me saying though, but 'braising' is a cooking operation, whereas 'brazing' involves melting braze rods to join two or more pieces of metal together!
Click to expand...

Indeed, I think they may have been 'brazed' !
 
Paddy_SP said:
... 'braising' is a cooking operation, whereas 'brazing' involves melting braze rods to join two or more pieces of metal together!
Click to expand...
True, but braising allows everyone to enjoy the fruits of your labor...
 
Nater_Potater said:
Paddy_SP said:
... 'braising' is a cooking operation, whereas 'brazing' involves melting braze rods to join two or more pieces of metal together!
Click to expand...
True, but braising allows everyone to enjoy the fruits of your labor...
Click to expand...

Only if you're a good cook! :mrgreen:
 
Bean oil is hydroscopic too so internal rust becomes a possibility.
Don't ask me how I know.
 
Hearth copper brazing is very old hat and has many problems associated with it some of which are replicated using induction brazing as the components are open to the atmosphere, though ideal for many applications where the final shape is not critical or there are no further machine processes to be conducted. Even in controlled environments, the braze process and atmosphere can be controlled much better, but if the components were suspect before brazing you just get a nicely brazed suspect component on completion, sometimes you can't identify the part until it fails in use.

Sadly and frustratingly, even with modern technology we still can not overcome or totally eliminate some of the problems that have more than likely been around from the start of the iron age.
 
Fast Eddie said:
Chaps,

I contacted SRM (UK based BSA specialist) who now make and sell new A65 cam followers (as used on JS kits).

Interestingly, the stelleite pads on original cam followes were attached via induction braising, and as we know, pads have been known to come off of various makes of OEM follower.

The new SRM followers are made slighty differently as the stellite is built up by welding rather than relying on seperate braised on pads. This is the same process used to build up stellite faced cams, and as far as I am aware, provides a very robust finished product.

So I think I'll try some SRM followers and let y'all know how it goes!
Click to expand...

I've tried the "Hero 60" hardface welding on a cam. Very good stuff and if SRM is doing something similar then we can expect high quality reliable lifters. Thanks Nigel for the push in this direction. It should boost business for SRM a little and give an option for those going to the lightweight lifter setup for Nortons with special radius cam lobes. Makes it easier for me too since new lifters are readily available (for those who can afford them). I'll probably put them on my website soon but you can always get them direct from SRM.

BSA lifter cracked stellite ...
 
I doubt if the OEM and any other manufacturer, BSA, Triumph etc have used or would use induction brazing for the attachment of stellite tips as it would be very slow, expensive and poor way for them to do it. There are and have been many more economical and better methods around long before Commando's were made.
 
Madnorton said:
I doubt if the OEM and any other manufacturer, BSA, Triumph etc have used or would use induction brazing for the attachment of stellite tips as it would be very slow, expensive and poor way for them to do it. There are and have been many more economical and better methods around long before Commando's were made.
Click to expand...

A way I have seen in use recently for large scale operations is to paint on a kind of 'paste' between the two surfaces then put them through an oven. Not sure whether this is brazing or soldering of some kind though?
 
Fast Eddie said:
Madnorton said:
I doubt if the OEM and any other manufacturer, BSA, Triumph etc have used or would use induction brazing for the attachment of stellite tips as it would be very slow, expensive and poor way for them to do it. There are and have been many more economical and better methods around long before Commando's were made.
Click to expand...

A way I have seen in use recently for large scale operations is to paint on a kind of 'paste' between the two surfaces then put them through an oven. Not sure whether this is brazing or soldering of some kind though?
Click to expand...
You are describing furnace brazing (as Jseng1 mentioned previously), where all the necessary materials and components are present, i.e., parts are racked or fixtured with flux and brazing alloy present and run through a heating process to activate the flux, melt the brazing alloy and complete the bonding process. Rather than have someone brazing each part, furnace brazing allows racks of parts to be pre-assembled and all bonded simultaneously.

Not quite sure what Leadbeater's "hearth copper brazing technique" is, but suspect he was likely also referring to furnace brazing. I'm sure he'll amplify on the subject if this is not the case.

Similar process for surface mount circuit board manufacture, where all materials and components are present (except solder, rather than brass in this case) on the board and the board is conveyed through an appropriate temperature inert solvent vapor to accomplish same. Provides a very clean extremely well controlled process.
 
So, I ordered a set of SRM cam followers, their stellite faces are built up with weld rather than relying on brazed on pads (as discussed earlier) so I'll let y'all know how's these work out in due course.
 
Could you show us a close-up picture of the welded interface between the lifter body and Stellite pad on the SRM lfter? Would be interesting to see what it looks like since most of us are used to seeing the brazed line.
 
So were those followers being employed with special radius cams or simply Norton cams?? The wipe length shown looks to my old eyes like it is accress the whole length of the follower which suggests they were used with a Norton cam.
I bet there have been over the years a great many owners who have simply changed followers to A65 ones without realising they had to buy a special cam to go with them.
Anyway what was wrong in modifying Norton followers as per Mr Heles Domirace ones? It isnt as if one is going to rev a Norton to 8,000 plus and believe me they will rev to such rpm even with std followers especiallly when clutch slip occurs when already at 7,000 in third trying to get to ones marshaling post up on the mountain section of the TT course before road closure at about 6 A.M. in a gale with horizontal rain and sleet on the rise from Brandish to The Creg!! Of course when in position and freezing ones proverbials off early morning practice was cancelled!! Its a hell of a way to spend ones holiday!!! I notice in the lartest bumph from the TT marshals association that there is still a serious shortage on the mountain section so IF you go over there for the racing enroll for the mountain section either the sections Ramsey to Black Hut or Bungalow Bridge to The Creg....it gives great views of the racing and in my young days (many decades ago) we were given free tickets for the prize giving.
 
J. M. Leadbeater said:
So were those followers being employed with special radius cams or simply Norton cams?? The wipe length shown looks to my old eyes like it is accress the whole length of the follower which suggests they were used with a Norton cam.
I bet there have been over the years a great many owners who have simply changed followers to A65 ones without realising they had to buy a special cam to go with them.
Anyway what was wrong in modifying Norton followers as per Mr Heles Domirace ones? It isnt as if one is going to rev a Norton to 8,000 plus and believe me they will rev to such rpm even with std followers especiallly when clutch slip occurs when already at 7,000 in third trying to get to ones marshaling post up on the mountain section of the TT course before road closure at about 6 A.M. in a gale with horizontal rain and sleet on the rise from Brandish to The Creg!! Of course when in position and freezing ones proverbials off early morning practice was cancelled!! Its a hell of a way to spend ones holiday!!! I notice in the lartest bumph from the TT marshals association that there is still a serious shortage on the mountain section so IF you go over there for the racing enroll for the mountain section either the sections Ramsey to Black Hut or Bungalow Bridge to The Creg....it gives great views of the racing and in my young days (many decades ago) we were given free tickets for the prize giving.
Click to expand...

As stated in reply to your identical comment half way down the previous page... They were used with special cams.

If you want to read up further, check out JS Motorsports web site. I am running his stage one cam.
 
WZ507 said:
Could you show us a close-up picture of the welded interface between the lifter body and Stellite pad on the SRM lfter? Would be interesting to see what it looks like since most of us are used to seeing the brazed line.
Click to expand...

Here you go:


BSA lifter cracked stellite ...


BSA lifter cracked stellite ...


BSA lifter cracked stellite ...
 
From what i've read it looks like an oil with a fairly high zinc content is good for flat lifters/followers .

Not saying this is a cure for your problem, but maybe help ?.
 
chilly said:
From what i've read it looks like an oil with a fairly high zinc content is good for flat lifters/followers .

Not saying this is a cure for your problem, but maybe help ?.
Click to expand...

My 'problem' here is a strange 'crazy paving' style micro cracking appearance upon the stellite pads.

Upon further investigation, it seems that this may be 'normal', others have said this, and I checked an old box full of used Triumph and Nourish followers and they are ALL showing similar effects to a greater or lesser extent.

However, as these new welded versions were available, I thought I'd try them.

I strongly agree with your zinc comment and am using Red Line oil which has one of the highest levels of zinc additive of any oils.
 
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