cam chains with split links
- Thread starter Wardy 944
- Start date
Wardy 944
New member
You would'nt have to, it would be a simple case of splitting both chains, connecting the new to the old and rotating the cams clockwise to feed the new chain on.
My current chain has a split link [
]This I agree with, but shirly the least amount of disturbance to the cams the better.
red leader
New member
The chain is only as strong as it's weakest link.. Doesn't take long to do it right
VERY interesting.
I didn't look at every link on the chain on mine in detail, but wasn't aware that there was a split link anywhere in it - I've never heard it being mentioned.
Do you have any records of that chain being changed Darren? (I.E. Do you know if it is the original?)
Oli.
I didn't look at every link on the chain on mine in detail, but wasn't aware that there was a split link anywhere in it - I've never heard it being mentioned.
Do you have any records of that chain being changed Darren? (I.E. Do you know if it is the original?)
Oli.
Darren,
Interesting. I wonder where Nelson Porsche source their parts from?
I don't think that 13 years is a problem for a cam chain actually; there is nothing about it that will degrade with time (unlike the rubber cam belts), and as long as it doesn't corrode (which would suggest a load of other problems as well), I can't see why it shouldn't last indefinitely. The only thing that should mean they need changing is mileage.
(Others may see a good reason why age should matter for a cam chain ... I'm sure that they will post it here if they do.)
Oli.
Interesting. I wonder where Nelson Porsche source their parts from?
I don't think that 13 years is a problem for a cam chain actually; there is nothing about it that will degrade with time (unlike the rubber cam belts), and as long as it doesn't corrode (which would suggest a load of other problems as well), I can't see why it shouldn't last indefinitely. The only thing that should mean they need changing is mileage.
(Others may see a good reason why age should matter for a cam chain ... I'm sure that they will post it here if they do.)
Oli.
Its not the chain thats the problem but the white plastic guides top and bottom (the photo shows a nice pearly white new top one I believe). These are some form of plastic that degrades over time and goes a manky orange colour before fragmenting which then allows the chain to jump on the cam spockets. If you're lucky its 'just' 2 new camshafts. If you're unlucky (likely), its new head, shafts, valves etc. i.e worse scenario than a snapping cambelt. If you're doing the guides, seems only right to do the chain at the same time.
sawood12
New member
In all my time hanging around on this forum I don't recall ever reading anything that suggests an issue with the chain. I've read a few about there being possible issues with the cam sprockets (teeth breaking off, excessive wear etc.) on high mileage cars. I would have thought that it would be good practice to change the chain when/if you change your cam shafts due to cam shaft sprocket wear or cam wear/cracking.
vitesse
Active member
In high performance engines,it is always correct to fit fully rivetted chains-this eliminates risk of fatigue failure associated with split links where the loose plate cannot be an interference fit on the bearing pin shoulder-in fact there can't be a shoulder-the loose plate lets the 2 bearing pins spread & contract under load & can lead to the spring pin becoming loose with disasterous results.
vitesse
Active member
Sorry Khushy,but in normal engineering use,chains do not stretch,unless they experience loads above their yield point-what they do particularly in poorer quality products is wear too quickly through their gas carburised wearing layer,or case hardening & then more rapidly wear once they are operating in the softer underlying metal.
The normal extension allowance for a chain is around 2%,before it climbs too far on the sprocket teeth & starts to wear rapidly-with damage all round-so a 400mm length of timing chain,typically 3/8 " pitch could be 8mm longer than when new & that length contains 42 pitches of chain,each pitch or link having 2 bushes in which the bearing pins rotates-each having a case hardened surface,hopefully each wearing equally say 10 thou depth,ie a total of 20 thou a pitch would give an extension of over 21mm at which point it is way past it's useable normal life.Again ,it's fatigue free life is around 10 to the 6th million cycles reduced by the wear taking place.
Spring clips on bikes,lawnmowers etc are OK but rivetted joints will be more troublefree.[8|]
The normal extension allowance for a chain is around 2%,before it climbs too far on the sprocket teeth & starts to wear rapidly-with damage all round-so a 400mm length of timing chain,typically 3/8 " pitch could be 8mm longer than when new & that length contains 42 pitches of chain,each pitch or link having 2 bushes in which the bearing pins rotates-each having a case hardened surface,hopefully each wearing equally say 10 thou depth,ie a total of 20 thou a pitch would give an extension of over 21mm at which point it is way past it's useable normal life.Again ,it's fatigue free life is around 10 to the 6th million cycles reduced by the wear taking place.
Spring clips on bikes,lawnmowers etc are OK but rivetted joints will be more troublefree.[8|]
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