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Old Jun 11, 2019 | 09:11 PM
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Old Geezer
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Joined: Mar 2019
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From: france
Default Alignment of camshafts

Hi all..another question please.
I have seen some query on the forum previously about setting up the camshafts for belt replacement and difficulty with alignment of the pulleys in accordance with the manual.
My 4wd Cosworth head has been skimmed, valves ground in and a new set of Burton hydraulic lifters fitted. The car has vernier type camshaft pulleys fitted which I have set to centre to simulate the original pulleys. The exhaust cam can be set so that the 'arrow ' lines up with the top of the head casting no problem although it tends to creep back.
The inlet cam however springs past this point by a tooth or so and can only be aligned by turning it back with a wrench and holding it against quite considerable pressure . The turning moment past the book set point seems to be caused by the spring pressure of the opening of the valves on no3 cylinder as the camshaft lobe slips off the edge of the tappet and the cam cannot rest at the correct set point. The situation occurs at every 90 degree turn of the camshaft so that it is not due to any one pair of valves or can lobes.
Previous comment seems to say that the belt can be installed by holding the pulleys in the correctly aligned position with a wrench but this doesn't seem to be right somehow and I am worried about getting the cam timing right.
Do others have experience of this problem and know what causes it?
Thanks
Many thanks.
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