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nissan
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Hi What nonsense, that's a 4-stroke after every two revolutions of the crankshaft, the camshaft markings must be correct again. the valve drive is offset by two teeth
Wrong. It depends on how many links there are in the chain compared to the number of teeth on the crank gear. If you look closely you will see that both those cam gears are out by two links compared to the chain markings. If you go to the trouble of taking off the timing cover you will see that the crank gear is also off by two links which will put it in correct phase with both the cams.

You will find there is something like 60 teeth on each of those cam gears and 30 on the crank gear Each link of the chain covers 2 teeth and there will be something like 88 links in the chain which means there is room for 176 teeth on the chain which isn't a nice multiple of 30 so once the chain does a full lap of the timing gears it will be 2 teeth out from the crank gear. If there were 90 links then there is room for 180 teeth which would mean that 6 turns of the crank for one lap of the chain which would make the marks line up again but with 88 links you will need 44 turns of the crank for them to line up.

Edit: just varied the maths a bit to illustrate a two link difference.
 
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