R56 Timing Issue

[jnhenderson]

I have a 2008 Cooper R56 Non s, i recently took on changing the cylinder head and a variety of other parts. Obviously the timing chain needed to come out for this so i got all the locking tools etc. and carried on. Today i got around to putting it all back together however when i went to check the timing i first found that the pistons had about an inch difference when the cams were facing up. So i kept cranking the engine to see if it would fall further out of time but it didn't. I randomly turned the crank backwards and i found that the crank would move about an quarter rotation before the timing chain would turn and just before the chain turned the timing was correct. I assumed that there was chain slack around the crank gear but the tensioner was in and then i notice that when i turned the crank the timing chain guide rail on the intake side would move with it causing the tensioner to be compressed and decompressed. Is this meant to happen with the tensioner? or have i simply got excess chain caught around the crank chain gear? or have i somehow got my guide rail caught between the crank bolt and the chain gear? (i assumed this would just break the plastic guide rail after turning it a couple of turns). Or am i just missing something obvious? Any help would be great!

[Elliot2000]

Firstly are you turning the engine the right way? Should be clockwise from the crank pully- it’s quite an obvious thing but I have seen people do worse.

And did you have the tensioner fully in before you tightened the cam sprockets? It sounds like cam sprockets were tightened before the tensioner was tbh and that you had too much slack on the tensioner side of the chain

You could loosen off the cam sprockets again and check if there is any slack in the chain anywhere with them loose - shouldn’t be any. The top chain that sits between the top of the cam sprockets should sit above the chain and not under it- again I’ve seen someone do this.

[jnhenderson]

Elliot2000 said:

Firstly are you turning the engine the right way? Should be clockwise from the crank pully- it’s quite an obvious thing but I have seen people do worse.

All i can say is that i am that foolish that i reset my timing 4 times before i read this post and then proceeded to kick myself... Thank you i may have been going for hours

[Elliot2000]

Well at least it’s sorted and it didn’t cost anything