Catastrophic camshaft and follower failure - any ideas?

Peter Holmes

Well Known and Active Forum User
VOC Member
Cams

I would find it very hard to imagine that you could have a sweetly running Vincent for 4000 mls if the valve collars were clouting all four valve guides at 3000rpm, my money is on poor quality parts, if the cams and followers had reached sufficient temparature to soften all those surfaces I would imagine the whole lot would have been blued and the failure even more catastrophic, if you can file and remove metal from an untouched surface on a cam follower I would think that you have found you problem, or at least some of it, did you acertain why the valve lifter failed, I only ask because it also points to poor quality parts or workmanship.

Good Luck Stuart, you seem to really enjoy Vincent ownership, I hope you fix it soon.

PS If it is any consolation everything is fixable, when I first got my Vincent in 1965 the timing chest and rockers were so knackered the previous owner had ground away the top half of the rocker thread to continue getting adjustment, having said that my cams and followers still looked in better nick than yours do right now!
 

BlackLightning998

Well Known and Active Forum User
VOC Member
Exhaust Valve Lifter

Peter,

We found the split pin (69) in the bottom of the timing chest (luckily). The operating rod for the front cylinder had then come adrift from the rear (ET166 had dropped out of ET69R). Once this has happened it had somehow got itself wedged and stuck - forcing the front exhaust valve open. The end had been snapped off the spring (ET129) but again luckily we found it in two pieces down at the bottom of the timing chest so I'm pretty confident we have no large pieces floating around - that's not mentioning where the "wear" off the cams and followers has gone though!

I had "felt" something strange in the exhaust valve lifter the last couple of times I had used it but couldn't quite put my finger on it, my starting method is as taught by my father, ease over compression using the lifter and then a positive downward stroke with no lifter in operation to fire.

And that's when I don't cheat and press the button to start....

I tend to use the lifter to stop the engine at tickover only less than 50% of the time (in petrol stations for instance) - usually I prefer to shut the fuel off and run the bowls dry.

I am now going to fit a "kill" switch into the circuit with the electronic igniton now that I have checked with Francois Grosset that this is an acceptable way to stop the bike with one of his electric starters fitted.

Yes - I am loving the bike to bits - it does most of my motorcycling miles now - I really enjoy riding it and am so looking forward to the Manx GP at the end of the month (so here's hoping I can get it all sorted and back together by a week on Friday - hence the rush).

Trying to look on the bright side (trying hard) at least it happened here rather than in the IOM - and within an hour of me diagnosing the stuck exhaust valve on Wednesday and reaslising it was beyond me to sort it I had two VOC members offering to fix it for me (both of them putting themselves out to do so), and within 24 hours it was in one of their garages, stripped, examined and spare parts (Godet manufactured cams, Maughan manufactured followers cause unfortunately Russ Kemp didn't have cams) were ordered and in parcels on their way - all with a bike almost 60 years old - now that's just a wonderful story in itself. It gets better - Patrick Godet sent me the bits cause I needed them in a hurry and then said we could sort the money out afterwards. He gets a Gold Star (not a BSA one) in my book.

The bike has always been noisy on the timing side from when I got it back from Australia after the owner had had the work done - with just 12 miles on the clock from an engine re-build - everything replaced on the timing side - my Dad noticed it and also the chap who is helping me fix it this time noticed it last year when he helped me with a couple of other bits when it had less than 1000 miles on it. The bloke who did the engine said that it might quieten down as the new steel idler ran in. I have often admired near silent bikes at the various meets though - have you listened to Colin Pearson's Shadowised Rapide - silent! Goodness knows what stress I've caused it, after 2500 miles I've had it up at the magic number once or twice.

However, again trying to look on the bright side (still difficult) I needed to take the kickstart cover off to re-grease the electric start sprag clutch (every year or 3500 miles) and was putting it off as it was a pain to remove the pipes - so I did it yesterday whilst it was all in bits. Reference your comments below - I also found a couple of loose bits inside the kickstart cover that should have been tight but weren't - perhaps that'll sort out the gearchange then!!!

I hope and imagine that if I make the Manx, then as I'm riding it round the Island the sheer shock and disappointment of what I found in the Timing Case will have abated, and I may even have got over the pain of the price of new cams (ouch!). I should have a pretty big grin back by then, but am still finding it pretty tough right now I have to say........and I've certainly learnt alot from looking over the shoulder of the chap stripping my engine yesterday, I even turned the odd spanner myself (under guidance).

Your bit about your bike caused me to laugh, when I got mine back with it came two large army ammunition boxes full off all the bits that had been taken off the bike and replaced - in there are 4 cams and 7 followers (haven't found the eighth yet) - every single piece looks like it would still do service to me.......ebay here I come to try and soften the expense of my repairs.

Cheers

Stuart

I would find it very hard to imagine that you could have a sweetly running Vincent for 4000 mls if the valve collars were clouting all four valve guides at 3000rpm, my money is on poor quality parts, if the cams and followers had reached sufficient temparature to soften all those surfaces I would imagine the whole lot would have been blued and the failure even more catastrophic, if you can file and remove metal from an untouched surface on a cam follower I would think that you have found you problem, or at least some of it, did you acertain why the valve lifter failed, I only ask because it also points to poor quality parts or workmanship.

Good Luck Stuart, you seem to really enjoy Vincent ownership, I hope you fix it soon.

PS If it is any consolation everything is fixable, when I first got my Vincent in 1965 the timing chest and rockers were so knackered the previous owner had ground away the top half of the rocker thread to continue getting adjustment, having said that my cams and followers still looked in better nick than yours do right now!
 
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andygbsmith

Forum User
Non-VOC Member
I would imagine that the most likely cause is the hardness of the cams and followers.
Due to the damage to them it would be pointless getting them tested and there appears to be enough oil floating around to discount a lack of lubrication.
I'm surprised you didn't have issue's with valve adjustment and performance as the problem worsend.
My real concern is all that material has been going around your engine.
You say that you changed the oil every 500 miles, was there no sign of debris? did you also change the filter? again any sign of metal.
If it was my bike I think I would pull the motor down and have a good look, it could end up cheaper in the long run.
Andy
 

Tom Gaynor

Well Known and Active Forum User
VOC Member
Worn cams and cam followers

Much time and money has been spent improving the lubrication on Sunbeam S7 and S8 motors because cams and rockers wore horrendously. Mine did. I replaced them, without altering the lubrication system, at about 13,000 miles. They're perfect, at over 33,000 miles. It's generally accepted now that (some of?) the original factory parts were deficient in the hardening department, and that BSA were a bit backwards at coming forwards to admit it. My guess is that yours are (were) too.
I bought "105" cams from Gary Robinson. I knew enough to send him the cam followers too. Last time I looked, about 3000 miles on, they were still perfect.
 

MartinRestorer

Forum User
Non-VOC Member
Hi Stuart
I would agree with Peter. If not insuficiant oil supply, the two faces of metal are eating each other, as mild steel.I had Gary Robinson from IOW
harden tip and reprofile my cams and followers to a mk3 profile he may be the man to send your worn cams and followers to for his assessment of the quality of metal and he could stalite tip and reprofile them as spare reserves.If fault is not first found.
Also a thought about your photos of your rocker bearing access to your valve looks tight and damaged do you have enough clearance for the rocker action. I ask this as I am fitting a new head to my comet engine
that needed extra material taken out for clearance?Hope you get the carrot [IOM] Im envious as my vincents are far from mobile.
Keep us posted Martin
Peter,

We found the split pin (69) in the bottom of the timing chest (luckily). The operating rod for the front cylinder had then come adrift from the rear (ET166 had dropped out of ET69R). Once this has happened it had somehow got itself wedged and stuck - forcing the front exhaust valve open. The end had been snapped off the spring (ET129) but again luckily we found it in two pieces down at the bottom of the timing chest so I'm pretty confident we have no large pieces floating around - that's not mentioning where the "wear" off the cams and followers has gone though!

I had "felt" something strange in the exhaust valve lifter the last couple of times I had used it but couldn't quite put my finger on it, my starting method is as taught by my father, ease over compression using the lifter and then a positive downward stroke with no lifter in operation to fire.

And that's when I don't cheat and press the button to start....

I tend to use the lifter to stop the engine at tickover only less than 50% of the time (in petrol stations for instance) - usually I prefer to shut the fuel off and run the bowls dry.

I am now going to fit a "kill" switch into the circuit with the electronic igniton now that I have checked with Francois Grosset that this is an acceptable way to stop the bike with one of his electric starters fitted.

Yes - I am loving the bike to bits - it does most of my motorcycling miles now - I really enjoy riding it and am so looking forward to the Manx GP at the end of the month (so here's hoping I can get it all sorted and back together by a week on Friday - hence the rush).

Trying to look on the bright side (trying hard) at least it happened here rather than in the IOM - and within an hour of me diagnosing the stuck exhaust valve on Wednesday and reaslising it was beyond me to sort it I had two VOC members offering to fix it for me (both of them putting themselves out to do so), and within 24 hours it was in one of their garages, stripped, examined and spare parts (Godet manufactured cams, Maughan manufactured followers cause unfortunately Russ Kemp didn't have cams) were ordered and in parcels on their way - all with a bike almost 60 years old - now that's just a wonderful story in itself. It gets better - Patrick Godet sent me the bits cause I needed them in a hurry and then said we could sort the money out afterwards. He gets a Gold Star (not a BSA one) in my book.

The bike has always been noisy on the timing side from when I got it back from Australia after the owner had had the work done - with just 12 miles on the clock from an engine re-build - everything replaced on the timing side - my Dad noticed it and also the chap who is helping me fix it this time noticed it last year when he helped me with a couple of other bits when it had less than 1000 miles on it. The bloke who did the engine said that it might quieten down as the new steel idler ran in. I have often admired near silent bikes at the various meets though - have you listened to Colin Pearson's Shadowised Rapide - silent! Goodness knows what stress I've caused it, after 2500 miles I've had it up at the magic number once or twice.

However, again trying to look on the bright side (still difficult) I needed to take the kickstart cover off to re-grease the electric start sprag clutch (every year or 3500 miles) and was putting it off as it was a pain to remove the pipes - so I did it yesterday whilst it was all in bits. Reference your comments below - I also found a couple of loose bits inside the kickstart cover that should have been tight but weren't - perhaps that'll sort out the gearchange then!!!

I hope and imagine that if I make the Manx, then as I'm riding it round the Island the sheer shock and disappointment of what I found in the Timing Case will have abated, and I may even have got over the pain of the price of new cams (ouch!). I should have a pretty big grin back by then, but am still finding it pretty tough right now I have to say........and I've certainly learnt alot from looking over the shoulder of the chap stripping my engine yesterday, I even turned the odd spanner myself (under guidance).

Your bit about your bike caused me to laugh, when I got mine back with it came two large army ammunition boxes full off all the bits that had been taken off the bike and replaced - in there are 4 cams and 7 followers (haven't found the eighth yet) - every single piece looks like it would still do service to me.......ebay here I come to try and soften the expense of my repairs.

Cheers

Stuart
 

BlackLightning998

Well Known and Active Forum User
VOC Member
Latest update - any more thoughts?

Evening All,

To keep you posted here is an update:

1 - New cams, followers and exhaust valve lifter parts on their way (ouch!)

2 - Oil and Debris
Andy asked about it - there was a little bit on the end of the magnetic sump plug and a tiny bit of discolouration here and there in the oil on each change - but nothing that concerned me when it is an alloy engine with a load of new bearing/working/wearing parts all making friends inside. I have kept all the oil changes marked in sequence (anal) and the cartridge filters bagged and marked so I will take time tomorrow to sieve the oil and open up the cartridges to have a closer inspection. The oil dropped from the timing chest when we opened it up is smooth to the feel and no visible debris.

3 - Valve Springs
Peter asked about these, and funnily enough Patrick Godet's first thoughts were of valve springs when I rang him to order the new cams - and sure enough his measurements are spot on (thanks Patrick) - the outer springs actually fitted in my engine are 0.160" and KTB says standards are 0.150" - or 04.06mm versus 03.75mm for the younger chaps, so it looks like I have stronger than standard springs in the bike and perhaps this has been a contributing factor to the problem? What do people think (before I change them please)?

4 - So more parts....
So the heads are coming off and all the necesary parts to replace the springs back to standard are ordered.....(ouch again!!)

So, looks like I might just make the Manx GP, but you'll all have to excuse me the Annual Rally as I think I won't have anything left for the £8 B-B-Q now!!!!!!

Oh - and Peter asked if I still like Vincents, I love them, and particularly this machine and this experience is not going to put me off yet - but I am not too happy at the moment.

Regards and thanks to all - grateful for any further thoughts and advice.

Stuart
 
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clevtrev

Well Known and Active Forum User
VOC Member
Evening All,

To keep you posted here is an update:

1 - New cams, followers and exhaust valve lifter parts on their way (ouch!)

2 - Oil and Debris
Andy asked about it - there was a little bit on the end of the magnetic sump plug and a tiny bit of discolouration here and there in the oil on each change - but nothing that concerned me when it is an alloy engine with a load of new bearing/working/wearing parts all making friends inside. I have kept all the oil changes marked in sequence (anal) and the cartridge filters bagged and marked so I will take time tomorrow to sieve the oil and open up the cartridges to have a closer inspection. The oil dropped from the timing chest when we opened it up is smooth to the feel and no visible debris.

3 - Valve Springs
Peter asked about these, and funnily enough Patrick Godet's first thoughts were of valve springs when I rang him to order the new cams - and sure enough his measurements are spot on (thanks Patrick) - the outer springs actually fitted in my engine are 0.160" and KTB says standards are 0.150" - or 04.06mm versus 03.75mm for the younger chaps, so it looks like I have stronger than standard springs in the bike and perhaps this has been a contributing factor to the problem? What do people think (before I change them please)?

4 - So more parts....
So the heads are coming off and all the necesary parts to replace the springs back to standard are ordered.....(ouch again!!)

So, looks like I might just make the Manx GP, but you'll all have to excuse me the Annual Rally as I think I won't have anything left for the £8 B-B-Q now!!!!!!

Oh - and Peter asked if I still like Vincents, I love them, and particularly this machine and this experience is not going to put me off yet - but I am not too happy at the moment.

Regards and thanks to all - grateful for any further thoughts and advice.

Stuart
If you get your decimal points in the right place, the younger elements might get it.
 
Last edited by a moderator:

greg burt

Well Known and Active Forum User
Non-VOC Member
cams

Stuart
A few questions if I may.
1 What oil(Brand) were you running before you changed to (Procycle oil) ?
2 How many miles has this Procycle oil been in use ?
3 You would have changed the oil and filter at least 7 times in 4000 mls ( the oil would have to be metallic if the wear started 4000 mls ago)?
4 How many times have you adjusted the tappets ?(Looking at your photos you would have been chasing the tappet adjustment from the start)
5 one of your recent threads stated you had a pushrod stuck in a follower and did you have the timing cover off to rectify this problem ?( If so you would have seen the Problem occuring )
6 I "presume" the cams in question are Mk3s ?(Not high Lift)
7 Looking at your photos, I get the impression the cams are Blue from Heat ?
Look forward to hearing from you.
Greg
 

BlackLightning998

Well Known and Active Forum User
VOC Member
Hi Greg, here's the reply:

Hi Greg,

1 - Oil
15/40 mineral oil throughout except for whatever was in the bike when I bought it - I ran than for 500 miles and changed it. No metallic oil - as I said, I have saved every change and filter - tomorrow I will sieve the oil and open up the filters to check. 9 out of 10 times Procycle and once Halfords own brand ( a car accessory shop in the UK ).
2 - Miles
2500 miles. One fill with whatever was in it when I bought it, one fill with Halfords as above and 1 litre of what was in the petrol station when I went to the Riders Rally and it ran low after 400 miles on the way home having been on the motorway at 70 MPH for a couple of hours. Still loads visible in the oil tank and returning through the tank though - just low below the filler neck.
3 - Metallic
See my earlier note reference what I found and felt in the oil when I drained it each time - I looked and studied it meticulously.
4 - Valve Clearances
There aren't any tappets in a Vincent - but I have done the valve clearances twice - first time after I torqued the heads down properly after running in as instructed and then the second time about 800 miles ago - both times took up a little adjustment - but nothing exorbitant - I was told it as a little unusual to have to do it a second time though.
5 - Pushrod stuck
I lifted it out of the tube having removed the tank - and polished it and replaced it spinning fine - it spins fine now - of course I now suspect that the particular cam follower getting hot had contributed or caused that particular problem.
6 - Cams
They are described in the invoice for the engine work as Mk 3 105 degree. I know you know who did the engine work and they are his cams. The profile looks nothing like an original mark 3 that I have put alongside it though as a matter of interest.
7 - Blue from heat
The cams are not blue - but the followers certainly are - but with that level of friction taking place I guess you'd expect to see that. I suspect that the heat in the followers is what has caused the stuck pushrod and I now know that Russ Kemp was right when he suggested that I open the timing side and find out what was causing the stuck pushrod earlier on. Interestingly a completely opposite view was taken by some pretty experienced Vincent engine guys which was to leave it alone completely. If I had opened the timing case I may have found the wear problem earlier, or even the fault being caused with the exhaust lifter which has probably excerarbated the problem.

Hope that helps - look forward to your views Greg as I have watched your comments being pretty much on the money.

Regards

Stuart
Stuart
A few questions if I may.
1 What oil(Brand) were you running before you changed to (Procycle oil) ?
2 How many miles has this Procycle oil been in use ?
3 You would have changed the oil and filter at least 7 times in 4000 mls ( the oil would have to be metallic if the wear started 4000 mls ago)?
4 How many times have you adjusted the tappets ?(Looking at your photos you would have been chasing the tappet adjustment from the start)
5 one of your recent threads stated you had a pushrod stuck in a follower and did you have the timing cover off to rectify this problem ?( If so you would have seen the Problem occuring )
6 I "presume" the cams in question are Mk3s ?(Not high Lift)
7 Looking at your photos, I get the impression the cams are Blue from Heat ?
Look forward to hearing from you.
Greg
 

greg burt

Well Known and Active Forum User
Non-VOC Member
cams

Stuart
On the face of it I would be getting the oil checked(chemist)
There is a few of us running these cams,( 4 of us in my area) and to my Knowledge No Problems .
My Mk2s have had one adjustment in 10500 mls and that was at 500mls( sorry for using the term tappets)(I also use 10w-60 full synthetic)that is just my choice, another word use a good quality and Brand oil castrol ,Valveline etc
I had an experience with a Mazda 3500 Deisel some years ago,it ran out of go ,on stripping, the cam shaft , followers and oil pump were (well like yours)the rest of the Engine was ok . I figured the oil pump was the problem with all the hardening off the teeth and pump shaft , rebuilt the problem area , filled it with Mobil Delvac and No problems for 5000 ks , the owner did his own oil change with his own oil , 1200ks later same problem, had the oil tested, the chemists report read may be used externally for warding off moister (Low grade)similar to WD40. I know this doesnt soften the blow for you it just had a similar ring to it ( thats why I was asking so many Questions).
Stuart I have NO affiliation with the said supplier.
Will be very interested with the out come . GOOD LUCK
Greg
 
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