Worn PW3 cam

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Madnorton, re post [HASHTAG]#365[/HASHTAG]

I cannot remember any previous post on any topic that contained so much rubbish, but this one hits the jackpot !

I may have to get to the open day to see for myself just what kind of person it is that can come out with this stuff.

Four paragraphs of mostly off topic ramblings, but the last one is just impossible to believe.

I had to look at the calender after I first read this to satisfy myself that it was not April 1st


Your're welcome, and if you know anyone in the UK that knows how to heat treat the alloy rods I have had forged - a European first according to the material supplier, then please let me know, as two major facilities in the UK are not sure they can. As for the last paragraph, the steel I am interested in, some on here will have handled it, fitted it or even flown in military aircraft using it. It is hugely more expensive than S132. It has been used to replace gears and can be made two 3/4 the size of the gear it replaces and still handle the same power - it is now on sale to the public. Deep pockets though.

As for the rest, read the research papers that are a little more hidden on the web, most are independent and come from research facilities and Universities in the US, UK and the far east, most confirm what we as owners know, some are surprising, especially the those that deal with modern oil and surface finishes, machined, polished and coated, no wonder more oils are becoming so engine specific.
 
Few people jumping the gun here, suggest a good hard look at oil type, servicing/ change periods and most importantly what oil pressure is being run? for every 20-30 Nortons I see maybe one is fitted with an accurate guage so most owners/riders have no idea what the "HOT" operating temperature really is.My early hardbound Norton-Villiers workshop manual for 750,s, is one of the few publications that actually gives an actual figure[ Quote /at the timing-cover take-off point pressure should be 45-55PSI , when the oil is at normal running temperature end Quote.
 
Few people jumping the gun here, suggest a good hard look at oil type, servicing/ change periods and most importantly what oil pressure is being run? for every 20-30 Nortons I see maybe one is fitted with an accurate guage so most owners/riders have no idea what the "HOT" operating temperature really is.My early hardbound Norton-Villiers workshop manual for 750,s, is one of the few publications that actually gives an actual figure[ Quote /at the timing-cover take-off point pressure should be 45-55PSI , when the oil is at normal running temperature end Quote.

Would not the reading of 45-55 be related in an important way to the RPM number? My gauge will get those numbers only at higher rev's, but at idle, it drops dramatically. Many others have reported the same...
 
Madnorton,
do yourself a favor and have Fullauto's camshaft examined and tested for hardness and granular configuration by a qualified establishment that specialises in such proceedures.

Until that is done, the reason for the failure you have put forward is conjecture only.

Hardness testing should involve transverse sectioning of two lobes preferably, one where the failure occurred, and another which is still in serviceable condition. Properly prepared and setup, a series of tests can then be carried out, to record the core hardness, and then by using a transverse method, a line of staggered tests can be performed.
Finally the samples after preparation and etching can be microscopically examined to reveal the granular structure.

If you have such testing done, you may well learn something to your advantage, and quite possibly that Fullauto's concerns are well founded !

Do the job properly, and in the meantime re quarrantine your stock of PW3 camshafts.
 
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Err, missing something here, UKAS, GKN, SAFRAN, SAFED approved test facility used, and yes the above was done. I was not the only one that tested the cam, it was also tested in Australia, maybe you would like to tell them to get it tested correctly too. I think you have not read the posts, or have jumped the gun a bit here or you would have realised it was tested in Aus.
So yes, I have done myself a favour and if you have anything useful to add please post it, or email it to me and I will follow it up.
 
Err, missing something here, UKAS, GKN, SAFRAN, SAFED approved test facility used, and yes the above was done. I was not the only one that tested the cam, it was also tested in Australia, maybe you would like to tell them to get it tested correctly too. I think you have not read the posts, or have jumped the gun a bit here or you would have realised it was tested in Aus.
So yes, I have done myself a favour and if you have anything useful to add please post it, or email it to me and I will follow it up.

Yes I tried to read all the posts and noted reference by Fullauto to the tests he had done in Australia, but unless I missed a post, the results were not fully disclosed, neither were any photo's of the wear posted, or of the tests carried out, which left it somewhat untidy at his end.
You no doubt received a copy of his test report, also the cams for you to have tested too. Your test results have as yet also not been posted.

You can be open about this and provide all the test information, or keep it all under wraps 'in house', in which case members of this forum will undoubtedly form their own opinions - if they haven't already done so.
 
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My attention has ben drawn to a request by Fullauto that the results of the Australian matalurgical tests are not publically revealed.
The possibility that his engine builder might be somehow implicated in the failure is one of the reasons given.

This being the case I can but wonder why Fullauto started the thread in the first place.

For myself, I regret having wasted so much time and effort on what originally appeared to be a very interesting problem.
 
My attention has ben drawn to a request by Fullauto that the results of the Australian matalurgical tests are not publically revealed.
The possibility that his engine builder might be somehow implicated in the failure is one of the reasons given.

This being the case I can but wonder why Fullauto started the thread in the first place.

For myself, I regret having wasted so much time and effort on what originally appeared to be a very interesting problem.

I did not say that at all. I said it was up to the engine builder to release the report. He is not a forum member and diesn't see this stuff. I will see him tomorrow and see if we can release it.
 
How is oil pressure related to cam wear when the cam is lubed by splash ?
Refer to section C21 and Fig C29 of your genuine Norton manual , shows how the return oil from the topend plays a vital part in lubing the cam/ followers, a low oil pressure setting reduces the amount of oil that gets to the topend, thus reducing the amount that runs down the rocker drains onto the cam, hence increasing the chance/ risk of inadequate lubing of the cam and followers. most of the very small amount[ 250-300ML] of oil that is in the sump/ crankcases gets pelted up the bores,not forward to the cam so this supplementary lubing of the cam via the rocker returns is vital to ensure long life of the cam/ followers.
 
You are correct in theory sir. But IMHO, if you run an engine that’s oil pressure is so low that it isn’t feeding the rockers the small amount that they get, cam wear will be the least of your problems.

Really, the cams main lubrication is from oil mist within the crank cases being thrashed around.

Of course, I wouldn’t argue against the need for good oil pressure! But I still maintain it is not a significant factor in cam wear.
 
The surface fatigue on the cam lobe nose is a result of spring pressure - it can't be anything else. The problem is there is over 5 different manufacture types of springs being fitted, of which two have been tested. There is nothing anywhere to suggest that any real testing of actual spring rates, configuration, fitted heights, lobe nose pressures etc that enables anyone to say that 'this configuration will enable the cam to last x thousand miles' very few Norton owners record this data.
The feedback so far is that the for those that want high spring rates for performance cams then standard springs will easily fill this role but you need to check for coil binding. But many in the cam design and manufacture world are saying these pressures are way over the top, but can't suggest any figures that would be suitable.
This is further compounded by the fact that many may have felt what they believe to be valve lofting (bounce) at high rpm, has anyone actually physically seen this and recorded it with a camera. I suggest it could also be resonance which would give the same affect but is different in how it occurs.
Fitted height is important as it determines max lift pressure, so to keep the max pressure down you may need to go to a weaker spring rate, determine the max pressure you are aiming for, work out your valve lift, use the spring rate and work back to find your fitted height and at the same time making sure you do not get coil bound. We believe that those who have made changes to avoid coil binding have actually lowered their max pressures to a lower level.
I have just fitted and currently running a new cam, it has 11.24mm of valve lift and uses radiused followers with the cam ground to suit, predictions on paper using a standard head, with 1mm modified valve stems is that fitted pressure would have been 89 lbs, max 246 lbs, when fitted with the FA head I had fitted 59 lbs, a surprise, and max pressure 199 lbs as my fitted heights were different to a standard head, It is running nicely and will hopefully be dyno'd on the 31st. It will also be ridden to Austria if it survives the dyno.
The standard springs have not changed since 1961 when they were changed to to suit a performance cam at the time which went on to become the 06.1084. in that day and age, the idea was 'that should be about right' and a 'add a little more to be sure' were most probably the norm. Currently with a standard cam and springs you are looking at around 104 lbs fitted and 226 lbs max. If you only changed the cam to a higher lift version ie PW3 and did not change anything else you are now at 246 lbs max lift. This for an engine that max revs at 8K is considered way to much pressure these days, with some suggesting that this is where they would want to be with stock racer at 10,000rpm and above.
Some have also found that too much and lift and the thought process that more spring pressure to control the vale gear have found it costs rpm and saps power, some automotive cams have been modified to lower the lift and re-tested and the engine has been found to rev higher and not have a reduction in power, the customers requirements were still exceeded by using less lift.

Sadly we have established some knowledge, but still don't have any concrete answers or solutions.

Tappets - some like them to just drop in, OK with a new barrel, but what if they drop in a used barrel - how much clearance do you have? Some can wield a spanner and that's it, they do not know or can't be bothered to fit a crucial part like a tappet. Yes, it is time consuming, but not hard and it is worthwhile.
Being cast iron they are a pig to grind and the stress in the material will take charge when released from the mandrel and thus the little high spots. Of all the people in the Norton world, and many who worked for Norton in Wolverhampton and Andover in the past cannot remember how they were made then to avoid the high spots.

See you at the open day on the 28th at Andover Norton, come down and we can discuss further.
 
The surface fatigue on the cam lobe nose is a result of spring pressure - it can't be anything else. The problem is there is over 5 different manufacture types of springs being fitted, of which two have been tested. There is nothing anywhere to suggest that any real testing of actual spring rates, configuration, fitted heights, lobe nose pressures etc that enables anyone to say that 'this configuration will enable the cam to last x thousand miles' very few Norton owners record this data.

See you at the open day on the 28th at Andover Norton, come down and we can discuss further.

The AN web site gives the open day date as the 29th.
Is this just another instance of 'the left hand doesn't know what the right hand is doing', and typical of the present day
Andover Norton ?

I would very much like to attend the open day, but would appreciate to be assured which is the correct date.
 
It’s definitely on the Saturday as confirmed in their last newsletter.

Worn PW3 cam
 
You are correct in theory sir. But IMHO, if you run an engine that’s oil pressure is so low that it isn’t feeding the rockers the small amount that they get, cam wear will be the least of your problems.

Really, the cams main lubrication is from oil mist within the crank cases being thrashed around.

Of course, I wouldn’t argue against the need for good oil pressure! But I still maintain it is not a significant factor in cam wear.
Correct in practise also , I have repaired literally dozens of norton motors that have succumbed to a lethal combination of wrong choice of oil, too long/ extended periods of oil change and low oil pressure, resulting in worn cams and followers. As I understand it the machine in question was ridden across the infamous Nullabor from perth to melbourne in some of the hottest weather of our summer{ a ride that I have done myself} a ride that will destroy the ability of some oils to adequately to protect the hard- working, high load area,s of cams and followers. Most riders don,t know what is happening to their oil under these conditions, they don,t have an oil gauge fitted to monitor the oil pressure and temperature[ yes you can maintain a check on both with just a pressure guage]so after a couple of days of hard riding[ lets say 400-500 mile days@70mph]if you are crossing the Nullabor that,s what you will be doing, there ain,t that much too see out there, believe me, the damage is done. I note that Paul Dunstall was a believer in providing his famous endurance racers/ record setters with an improved oiling supply to the camlobes/ followers, I wonder why?
 
Correct in practise also , I have repaired literally dozens of norton motors that have succumbed to a lethal combination of wrong choice of oil, too long/ extended periods of oil change and low oil pressure, resulting in worn cams and followers. As I understand it the machine in question was ridden across the infamous Nullabor from perth to melbourne in some of the hottest weather of our summer{ a ride that I have done myself} a ride that will destroy the ability of some oils to adequately to protect the hard- working, high load area,s of cams and followers. Most riders don,t know what is happening to their oil under these conditions, they don,t have an oil gauge fitted to monitor the oil pressure and temperature[ yes you can maintain a check on both with just a pressure guage]so after a couple of days of hard riding[ lets say 400-500 mile days@70mph]if you are crossing the Nullabor that,s what you will be doing, there ain,t that much too see out there, believe me, the damage is done. I note that Paul Dunstall was a believer in providing his famous endurance racers/ record setters with an improved oiling supply to the camlobes/ followers, I wonder why?

Factually incorrect.
 
Correct in practise also , I have repaired literally dozens of norton motors that have succumbed to a lethal combination of wrong choice of oil, too long/ extended periods of oil change and low oil pressure, resulting in worn cams and followers. As I understand it the machine in question was ridden across the infamous Nullabor from perth to melbourne in some of the hottest weather of our summer{ a ride that I have done myself} a ride that will destroy the ability of some oils to adequately to protect the hard- working, high load area,s of cams and followers. Most riders don,t know what is happening to their oil under these conditions, they don,t have an oil gauge fitted to monitor the oil pressure and temperature[ yes you can maintain a check on both with just a pressure guage]so after a couple of days of hard riding[ lets say 400-500 mile days@70mph]if you are crossing the Nullabor that,s what you will be doing, there ain,t that much too see out there, believe me, the damage is done. I note that Paul Dunstall was a believer in providing his famous endurance racers/ record setters with an improved oiling supply to the camlobes/ followers, I wonder why?

That’s a lot of contributory factors.

I still argue that, in an otherwise good engine with good oil etc, loss of pressure (not flow) will result on other catastrophic failures before cam wear becomes catastrophic.

If I understand correctly, Ken’s engine was in good shape apart from cams and folllwers. That, I believe, indicates that lack of pressure was not his root cause.

If it was, his big ends would show it.
 
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