oil feed to cams ???

redbloke1956

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Non-VOC Member
Hi all, I have been looking at my new cams, old cams, new and old cam spindle.....I noticed (on the old cam and spindle) that at a certain point in the cam rotation, the hole in each of the cam faces lines up with its respective oil feed hole in the cam spindle.
With the new spindle and the new or old cam, at no time do the holes align and with one of them it is not even close.
I was therefore given to thinking could this be the cause of premature wear of the cam and/or followers as noted by some members.
I understand that some oil will reach the cams by various other means but is that enough?
My apologies If this has been covered elsewhere in the forums but I have not yet found it.

Kevin
 

timetraveller

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VOC Member
The oil feed to the cams does not rely upon holes lining up. I normally put the spindles in so that the outlet hole in the spindle are pointing down wards, away from the thrust of the cams and followers. That way if there is any clearance the oil can get between the spindle and the cam bushes. The oil feed to the cams then goes from that 'reservoir' through the holes to the cams so it is important that there are holes all the way through from the cams and bushes down to this 'reservoir'. Put a fine drill through the holes in the cams to ensure that there is a hole all the way through to the centre.
 

deejay499

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VOC Member
Worth also checking all oilways in the timing chest. We just did one that had at least one oilway blocked as well as the jet in the top of the timing cover. We also found that the pressure release valve was solid with dirt and not moving.
 

clevtrev

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VOC Member
Worth also checking all oilways in the timing chest. We just did one that had at least one oilway blocked as well as the jet in the top of the timing cover. We also found that the pressure release valve was solid with dirt and not moving.

Tell us why the release valve needs to be moving , and what moves it ?
 

deejay499

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VOC Member
HI Trev. I always presumed it would move against the spring if pressure built up as in a blockage, but I am open to your wiser thoughts and experience, cheers.
 

Howard

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VOC Member
Always trust Trev to ask a pertinent question, then sit back and let us suffer!

I always thought the same as Deejay, but now I wonder if the pump is actually good emough to compress the spring, and if it did, do we want to run the engine with the main oil feed bypassing the main wear parts?

H
 

nkt267

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VOC Member
Personally I think that the quill would have to be blocked to get the release valve to lift,and possibly the cam and cylider feeds as well. Now standing by to be told I'm wrong :(..John
 

Len Matthews

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VOC Member
What you have consider is the effect of the pressure releif valve being stuck open. Oil will escape through the two holes in the timing cover instead of being forced into the big end quill and up the gallery that feeds the cam spindles and cylinder bores.
 

nkt267

Well Known and Active Forum User
VOC Member
I agree with you Len, sticking shut is not really a problem in my view as the working pressure on a Vincent appears to be very low maybe 3 to 10 psi.
Looking at my Comet though, if the valve stuck open the timing case would end up half filled with oil, the timing gear might get enough oil to operate satisfactorily. It would be anybodies guess to how long the bigend would last with just the splash from the crankcase reservoir, though I would think that cylinder lubrication would be ok. Still I freed my relief valve when I built the engine 'cos that was how it was made..john
 
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