Evening All,
Oh dear - isn't Vincent ownership fun......
I wondered if any members have any ideas on what caused pretty catastrophic camshaft and follower failure on my 4000 mile old engine. Pictures embedded below.
The story is that I came to re-start the bike after re-fitting my refurbished dynamo, only to find it fire on the rear cylinder and not on the front. I traced it to a stuck open exhaust valve and suspected the valve lifter mechanism.
On stripping the timing side today, sure enough the front and rear linkage had become seperated and the front had stuck open the exhaust valve.
However, then things get worse. On checking for other damage/issues we found that all four cam lobes were heavily worn/scored and all four followers were deeply scored and worn - see the pictures.
Everything was invoiced as new in the top end and timing side before I bought the bike. More new parts than would sink a Battleship.
The work was done in Australia - I don't yet know the origin of the new parts which were fitted, but we have narrowed down the problem to one of three causes, I'd be very grateful for any other ideas, comments or advice from members on what to check/look for in advance of fitting the new parts I ordered today (ouch!):
1 - Parts failure
Perhaps the cams or followers weren't properly hardened
2 - Oil Failure
I have been meticulous in checking the oil return immediately on firing the bike, changing oil and cartridge filter at 500 mile intervals including priming the cartridge and keeping to recommended running in speeds and loads. The timing case is lovely and oily throughout, the valve caps have always had a good covering of oil in them when I have removed them and the new stainless rocker feed bolts are all clear and running through when you blow them - no metering wires fitted. So whilst of course it is always a possibility - I just can't see it myself.
3 - High Lift Cams
The lower valve guide is visible in the picture attached - we were wondering whether such damage could have been caused by a mechanical problem, perhaps the valve collar is bottoming out on the top of the lower guide before full cam lift and this is causing the damage. The cams which have come out are stamped "3" but the profile does not look anything like some spare old "3"'s I've compared them to.
Have we missed something?
Regards
Stuart
Oh dear - isn't Vincent ownership fun......
I wondered if any members have any ideas on what caused pretty catastrophic camshaft and follower failure on my 4000 mile old engine. Pictures embedded below.
The story is that I came to re-start the bike after re-fitting my refurbished dynamo, only to find it fire on the rear cylinder and not on the front. I traced it to a stuck open exhaust valve and suspected the valve lifter mechanism.
On stripping the timing side today, sure enough the front and rear linkage had become seperated and the front had stuck open the exhaust valve.
However, then things get worse. On checking for other damage/issues we found that all four cam lobes were heavily worn/scored and all four followers were deeply scored and worn - see the pictures.
Everything was invoiced as new in the top end and timing side before I bought the bike. More new parts than would sink a Battleship.
The work was done in Australia - I don't yet know the origin of the new parts which were fitted, but we have narrowed down the problem to one of three causes, I'd be very grateful for any other ideas, comments or advice from members on what to check/look for in advance of fitting the new parts I ordered today (ouch!):
1 - Parts failure
Perhaps the cams or followers weren't properly hardened
2 - Oil Failure
I have been meticulous in checking the oil return immediately on firing the bike, changing oil and cartridge filter at 500 mile intervals including priming the cartridge and keeping to recommended running in speeds and loads. The timing case is lovely and oily throughout, the valve caps have always had a good covering of oil in them when I have removed them and the new stainless rocker feed bolts are all clear and running through when you blow them - no metering wires fitted. So whilst of course it is always a possibility - I just can't see it myself.
3 - High Lift Cams
The lower valve guide is visible in the picture attached - we were wondering whether such damage could have been caused by a mechanical problem, perhaps the valve collar is bottoming out on the top of the lower guide before full cam lift and this is causing the damage. The cams which have come out are stamped "3" but the profile does not look anything like some spare old "3"'s I've compared them to.
Have we missed something?
Regards
Stuart