Worn PW3 cam

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Well my last oil change has 4800 on it. [mostly one trip]
My needlejet holder fell out a long time ago...;)
 
Dances with Shrapnel

Don't misunderstand me - I am not suggesting pumping more oil into the crank case and I am not encouraging pressurized oil to the cam. What I am saying is that since the oil is already draining down the pushrod tunnels from the rockers - then you might as well direct it to the center of the cam lobes. The stock setup drains it down the chamfered side/corner of the lifters and sort of misses the lobe center.

This is not adding to the total amount of oil - just re positioning where the rocker oil drains to. Its a feature of the bronze tappet blocks and radiused BSA lifters. Ken Canaga turned me on to this setup when I was racing. The factory Norton dirt track racers were doing it. Ken showed/told me about the longevity of radius lifter cams compared to flat tappet cams and I was impressed. Below is a photo after a 5000 mile inspection. You can see some dark stain on the left lobe tip but everything else is clean. There is 40,000 miles on it now but no new photos.

Worn PW3 cam


Surely you don't object to oil dripping onto onto the centers of the cam lobes instead of to the sides.

Good idea. I can't recall if my tappet blocks had that feature or not. Several sources over several builds.
 
the one lifter pad looks pitted. Maybe its just the pic. Do you feel anything on the cam using your fingernail across the lobe tops. Put a dial indicator on the lobes and give us the numbers. I had 24600 Miles when I had my 74 engine going over. There was a slight ridge on the stock cam on one of the lobes which made me decide to drop in a Megacycle cam. Reground the lifters. I was about the 7th owner of this bike so who knows what oil they used. My engine had many issues when I got it. Including the idler dowel was missing in my oil pump when I got into it. Glad I did.
Cheers,
Thomas
 
Yes it is lightly pitted and one cam does have a ridge.
so will be replacing it.
Can´t measure anything at the moment .
sitting in the airport ,and will be away for 8 weeks.
cheers
 
So Stock Cams are not immune to wear either, my 74 running close to Fullautos mileage on his PW3 when I needed the rebuild. I sent my old cam core plus some others a few years back to comnoz and got a couple of re-welded cams in 12 and 12a grinds. I haven't got a chance to install them yet. If my 74 gets a refresh, then something will go back in. I will post pics of my Megacycle cam and I will post you mileage:D I've got 65000+ and counting.
Cheers,
Thomas
 
So Stock Cams are not immune to wear either, my 74 running close to Fullautos mileage on his PW3 when I needed the rebuild. I sent my old cam core plus some others a few years back to comnoz and got a couple of re-welded cams in 12 and 12a grinds. I haven't got a chance to install them yet. If my 74 gets a refresh, then something will go back in. I will post pics of my Megacycle cam and I will post you mileage:D I've got 65000+ and counting.
Cheers,
Thomas
Which Megacycle option did you go for?
 
Which Megacycle option did you go for?

oldmikew,
I had a 560-NR which would be the one closest to stock performance with flat lifters. I bought the bike at 23000 miles. I think I was the 6 owner. No idea how the bike or engine was treated or who monkey wrenched it prior but like I said earlier the engine had many issues.

I pulled the 74 engine at 24658 on the clock and swapped out another 73 850 engine.

then when completed and rebuilt,(74) was swapped back in at 38151. My rebuilt engines is now running up to +65 K miles and counting. I lost about +600 miles on a 4-day trip to Upstate NY at a rally when my Speedo gearbox decided to loose all the worm gear teeth.

Honest mileage from rebuild is +27000 K miles to keep with the cam wear subject going with mileage.

Cheers,

Thomas
 
Well. Haven't heard anything back from AN yet. Neither has my engine man.Testing seems to be taking a while. Meanwhile, my Norton sits in pieces. I am very unhappy. My engine man is furious.
 
I guess I don't understand what you are waiting for.
Whatever AN has to say about the issue, or the test results, or anything else, you're gonna use a new one anyhow, yes?
 
I guess I don't understand what you are waiting for.
Whatever AN has to say about the issue, or the test results, or anything else, you're gonna use a new one anyhow, yes?

My thoughts exactly.

You’ve already decided on a new cam from a different source Ken. How / why is AN analysis holding you up?
 
There is a problem. I want to know exactly what the problem is, with all sides agreeing on what that problem is before spending thousands more on another rebuild.
Put it this way. Would you rebuild a Norton at the moment, using a new cam and followers without a resolution to this issue? I don't understand what it is about this that you don't understand, or do you just accept a cam life of 1500 to 4000 miles as being a normal part of Norton ownership? AN have had the cams and followers for some time now. I want some resolution of the issue. I am still waiting on my Webcam from Jim, so my rebuild is on hold anyway.

If this was a new Hyundai, you'd be screaming your guts out. I didn't realise that Nortons were somehow different.

My followers are being refaced with Stellite 6, which doesn't seem to exist if you believe some.
 
Fullauto
If you removed cams and followers from a new Hyundai and had them both coated, and they subsequently failed, Hyundai would throw any claims out because you would have deliberately altered the original production specification of the items.
I will be very surprised if AN do not take a similar view.
Your problem is not one of lubrication, but of material incompatibility, and you should be asking the firm who did the coatings for answers
 
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Ken, you are proceeding with a hard faced Webcam in your rebuild. So, the findings of what was wrong with your chilled iron PW3 cam are likely to be largely irrelevant to your future set up.

I don’t think anyone is questioning your frustration or your persistence in getting to the root of the problem, on the contrary in fact, I think many of us are following this with great interest.

It was just your comment that AN are holding up your build that confused some of us... especially as you don’t yet have your new Webcam! Come on, just admit it, you were laying it on a bit thick there!

In your shoes, I would proceed with the build as soon as my new cam arrived. IMHO the AN analysis can happen in parrellel to your engine build. And, FWIW, I would be very surprised if their analysis declares any fault with the cam.

I think we all have to make our own choices, but often based on very little hard evidence, so hopefully your findings will helps many others. Personally, I decided long ago that hard welded cams and good oil with high zinc content where the way I would go.
 
Fullauto
If you removed cams and followers from a new Hyundai and had them both coated, and they subsequently failed, Hyundai would throw any claims out because you would have deliberately altered the original production specification of the items.
I will be very surprised if AN do not take a similar view.
Your problem is not one of lubrication, but of material incompatibility, and you should be asking the firm who did the coatings for answers

There is nothing wrong with the coating. It was the only thing keeping it all together, as confirmed by the metallurgist. I agree with you about the incompatibility of the materials. Personally, I am of the opinion that in the last few years, the hard facing of the lifters has changed, causing the problem. I have asked this question several times, and not received an answer.
 
Ken, you are proceeding with a hard faced Webcam in your rebuild. So, the findings of what was wrong with your chilled iron PW3 cam are likely to be largely irrelevant to your future set up.

I don’t think anyone is questioning your frustration or your persistence in getting to the root of the problem, on the contrary in fact, I think many of us are following this with great interest.

It was just your comment that AN are holding up your build that confused some of us... especially as you don’t yet have your new Webcam! Come on, just admit it, you were laying it on a bit thick there!

In your shoes, I would proceed with the build as soon as my new cam arrived. IMHO the AN analysis can happen in parrellel to your engine build. And, FWIW, I would be very surprised if their analysis declares any fault with the cam.

I think we all have to make our own choices, but often based on very little hard evidence, so hopefully your findings will helps many others. Personally, I decided long ago that hard welded cams and good oil with high zinc content where the way I would go.

I wish people would read posts a bit more carefully. I am not proceeding with the rebuild until I have a definitive answer. My cam is in transit. Again, would you rebuild an engine when there was a cloud over the components used? If you would, and risk another rebuild, then some people are more fith than I thought!
The rebuild is held up until AN come up with the goods, ergo, therefore, and amongst other things, my rebuild will be held up until I know the answer, agreed by all parties. This is really simple. Then, the Commando riders can get on with riding, and the rest can go back to their 27 page posts on what colour you should be painting your battery box.

I am extremely frustrated by this, because I am getting stuff criticising what I used, how I ride, that the colour of my bike is the cause of all this, and shit like, "do you run any oil in it?" FFS!

I just want a straight answer!

Which I am not getting. I'm told that the report is due shortly.
 
I just want a straight answer!
Good luck with that!
so far in this thread the cause for cam wear is either:
Stiff springs
or
Weak springs
or
Metallurgy
or
Coatings
or
Flat lifters
or
Pointy lobes
or
Not enough oil
or
Wrong zinc content in oil
or
Paint color
or
any combination of the above.

I think that if this group can't figure it out, nobody's going to.
 
I apologize that this post might not add anything to determining the cause of this particular failure, but I include it to make the point about how critical it is to have compatible materials in cam lobes and lifter surface. Back when CR Axtell first started grinding his own cams for Nortons he experimented a lot with different hard facing rods, and settled on one of the Stoody brand alloys (sorry, I don't remember which one) which worked very well with the Stellite (or whatever it really was) pad on the Commando lifters. This was back in the late '60s or early '70s, and that's the alloy that he used for a lot of years, with no real problems. Fast forward to a few decades later, roughly at a time just before the PW3 cam became available through Mick Hemmings and Norman White. Ax had made a batch of Commando cams, which were sold in lots to dealers in England, like Mick, for resale, as well as some to individual customers. Axtell started getting reports of failures in the cams, with severe lobe wear, and several of the damaged cams were returned to him. Axtell was always very careful about his reputation for quality, and was really disturbed about the failures. After metallurgical tests, he discovered that his welding supply shop had substituted another Stoody hard facing alloy, thinking it would work just as well. It was not compatible with the material on the lifter foot, and that was the cause of the disaster. Axtell lost a lump of money making good all the cams, and stopped selling Norton cams to retailers after that. For the rest of his career, at least as far as I know, he went back to only selling them to individual customers. This was all a long time ago now, and my memory isn't so hot anymore, but I think I've got all the essential details right.

Again, this may not have anything to do with Ken's camshaft problems, but it at least offers some food for thought.

As an aside, I got involved in this when I agreed to help avoid the customs fees by smuggling in a batch of 20 cams in my luggage on a business trip to England. Probably not one of my smartest moves, but exciting at the time.

Ken
 
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