knock-knock....

o0norton0o · May 13, 2016

Just came back from a short ride, and something is knocking down low.... I'm praying it's in the primary case, but I've heard 'chain slap' before and this new knock sound didn't sound like a loose chain slapping the primary case wall...

Oh well, I guess it's my turn to pull it apart and look...

Matt Spencer · May 14, 2016

KnAlternator Rotor , if there aint a W its not got welded magnets .

L.A.B. · May 14, 2016

Matt Spencer said:
if there aint a W its not got welded magnets .

The 'W' and welded magnets appear to be something of a myth.

http://www.britbike.com/forums/ubbthrea ... Post582074

For what seems for a lot of reasons you cannot "weld" magnets. Heat, and the effect of the magnets magnetic field on the actual welding process will cause all sorts of obstacles. It has been recommended that they might be laser welded, but laser welding didn't exist when the "welded" rotor was first marketed. I have seen many rotors that exploded and none of them were "welded!"

And As I mentioned above I have taken several of recent production apart and the only thing holding the magnets to the center was the magnetism. If these rotors are "welded" the process has nothing to do with attaching the magnets to the center.

gripper · May 14, 2016

I often wondered about welding magnets, doesn't seem feasible.

o0norton0o · May 14, 2016

....... and the answer is... The hardened face seperated from the body of the tappet. The seperated face was sitting right on top of the cam when I pulled the barrels. I wonder if it's repairable... ?

Everything else looked solid, I see zero damage on the bottom except for the tappet. The noise started in my driveway after a ride and I listened to it for about a minute and shut the bike off. It was loud enough for me to realize that I had to open it up and take a look....

Anyone know if the stellite face can be re-welded back on to the original tappet?? Anyone?

Danno · May 14, 2016

Don't bother. Just get a different tappet. And consider yourself lucky if it didn't do any other damage.

cjandme · May 14, 2016

Danno said:
Don't bother. Just get a different tappet. And consider yourself lucky if it didn't do any other damage.

ditto

Fast Eddie · May 15, 2016

Wow. You are A) very lucky to have caught it so early and B) very sensible in stripping it to check and not continuing to run it.

Did you fit the followers? Perhaps they are poor quality pattern parts?

I certainly would not try and repair it. Personally I'd buy a set of new genuine ones for peace of mind.

o0norton0o · May 15, 2016

It wasn't hard to make the decision to tear it down after having read swooshdave's thread where he had metalic particles in his oil, and then very soon afterward he blew a huge chunk of metal right out of his crankcase! In my case, I actually suspected that either one of my connecting rod cap nuts had come loose and the rod was slapping the journal, or the crankshaft bolts had loosened, and the crank was clapping together as it spun.

Either way, it was not a noise that anyone with any common sense would ignore. I never imagined it would be something like this... I'll add a picture later, once I pull the pair of tappets. It's a clean break. It makes me wonder how they weld the stellite to the body of the tappet, because the break looks so clean. At first, I theorized that the joint could be beveled and welded all the way around to re-attach it. It seems like that's how it has to be done when they are manufactured,... so why not repair it the same way...?

Anyway, Jim is gonna help me sort it out, so I'll be back on the road in a few weeks...

Danno · May 15, 2016

I would think the tips are induction-welded to the tappet bodies and there is probably some post-welding heat treatment to homogenize the assembly. In any case, it's not something that can be accomplished at an ordinary welding shop.

Fast Eddie · May 15, 2016

This was discussed a little while ago in another thread.

It was stated that these were furnace brazed by the factory. This is a process whereby a paste of flux and braze material is applied, the surfaces are placed together in some kind of jig, and trays full of such assemblies pass slowly through a large oven / furnace, coming out the other end brazed together. Its quite comon in the automotive industry to this day.

Personally, I would not attempt to repair such an item, especially when they are readily available.

o0norton0o · May 15, 2016

Fast Eddie said:
This was discussed a little while ago in another thread.

It was stated that these were furnace brazed by the factory. This is a process whereby a paste of flux and braze material is applied, the surfaces are placed together in some kind of jig, and trays full of such assemblies pass slowly through a large oven / furnace, coming out the other end brazed together. Its quite comon in the automotive industry to this day.

Personally, I would not attempt to repair such an item, especially when they are readily available.

Eddie, Thanks for that info. I am always curious about how things are manufactured. Sometimes my curiousity gets me into trouble and sometimes it gets me out of trouble.... (Last week a hole rusted in my 69 ford's transmission cooling line, I couldn't find replacement lines, so I decided to buy the generic tubes and bend it up myself.... and was sucessful!) I had a half assed idea to bevel both sides of the joint where the body of the tappet meets the stellite face and weld them back together. Then all I would have to do is grind off the excess... This way I would have a repaired part that already fits in it's tunnel. (I guess I am crazy, but that's how I think)

anyway, someone asked me to post a picture, so... here it is.

Madnorton · May 15, 2016

Here is what I see, a piece of 'stellite' tip detached from the tappet and the remainder of a considerable piece of stellite on the body, surely no one would have put an additional piece on top of the original tip!

o0norton0o · May 15, 2016

it's not a second piece of stellite, it's just the grind mark on the body of the tappet where the tip was ground back so it wouldn't pertrude over the edge of the body. The photo is misleading you... I'm sending it to Jim Comstock, so if there's anything out of the ordinary, I 'm sure Jim will say something....

comnoz · May 15, 2016

yes, that is just the bevel on the edge, nothing unusual there.

I do have the powder, the flux and the furnace to furnace braze the stelite -but I have never tried it on a lifter.
Maybe I will try it and see how it works in the spintron....

Bernhard · May 16, 2016

o0norton0o said:
....... and the answer is... The hardened face seperated from the body of the tappet. The seperated face was sitting right on top of the cam when I pulled the barrels. I wonder if it's repairable... ?
Everything else looked solid, I see zero damage on the bottom except for the tappet. The noise started in my driveway after a ride and I listened to it for about a minute and shut the bike off. It was loud enough for me to realize that I had to open it up and take a look....
Anyone know if the stellite face can be re-welded back on to the original tappet?? Anyone?

Unlike me you are extremely lucky with your cam follower, my stellite tip disintegrated before I heard the sound of the engine -the whole tip disappeared destroying the hole where the cam followers went, but strangely enough, not the cam.
I would not attempt to repair this, for peace of mind listen to the other guys on the webpage –but if you insist- it is not widely known but you can get sheet brazing (sheet ) in different thickness don’t ask me where, I haven’t used/worked with any for over 40 years, then you will have to get the tip to sit accurately while it is still red hot, and when cool grind the whole sides of the tip and the face accurately-not worth the hassle-unless you are a skinflint :shock:

Madnorton · May 16, 2016

If you braze it with flame, belt feed furnace braze methods, induction etc then it will very likely fail. There is still a large piece of stellite on that body - the tip is not a flat piece of stellite, it has a shouldered portion that fits inside the end of the cast body - dissect and you will see, there is also another mark on that body that indicates to me that it was not made prior to the 90's. I am certain Jim will also be able to see what I can see and tell you the same, I imagine he has seen enough them in various broken states.

o0norton0o · May 16, 2016

Madnorton said:
there is also another mark on that body that indicates to me that it was not made prior to the 90's.

There's ZERO chance of that being true because.... I've owned this bike since I was 19 years old. I am 57 now. The tappets were not replaced when I rebuilt this engine 25 years ago, so unless someone sent some tappets back in a time machine to be installed in my engine sometime in the 70's, the tappet you see in the picture has been inside my bike since at least 1977.

So, ... What's your point? I don't see where you're going with this?

comnoz · May 16, 2016

Madnorton said:
If you braze it with flame, belt feed furnace braze methods, induction etc then it will very likely fail. There is still a large piece of stellite on that body - the tip is not a flat piece of stellite, it has a shouldered portion that fits inside the end of the cast body - dissect and you will see, there is also another mark on that body that indicates to me that it was not made prior to the 90's. I am certain Jim will also be able to see what I can see and tell you the same, I imagine he has seen enough them in various broken states.

This is an OEM lifter. It is not a later design spiggoted lifter , so there is no shoulder and no part of the Stelite still in the body.
The OEM lifter of that vintage simply had a flat piece of Stelite furnace brazed to the closed bottom of a cast steel body.
Later "spiggoted" lifters had a body with an open bottom and a shoulder on the Stelite that fit up into the lifter body. On the later lifters the weld is visible if you look inside the lifter through the side hole. Jim

gripper · May 20, 2016

The latest Tappet / cam followers from Andover Norton are an improved design I believe, where the stellite foot is shaped to engage in a slot in the cast iron body prior to brazing

knock-knock....

o0norton0o

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