Timing question

[Figoulu]

Hi gents

I did the valve adjustment on my 230SL
When turning the engine by hand from the crankshaft i felt a hard point

After some investigations i understood that one valve has gently kissed the 6th piston (smooth valve shape engraved on the soot on the top of the piston) while the alignment between the index of the crankshaft of the pulley didn’t match with the niple of the camshaft

I’m now in a process of opening the timing chain with the removable link and realign both index by turning the crankshaft independently from the camshaft.

Is that gonna be a correct move ?

Thanks

[Benz Dr.]

Which way did you turn the crankshaft? No way it should ever hit just by turning if it wasn't hitting before that point. Turn it backwards with a worn or loose chain? Yeah, it could hit.

[Figoulu]

Which way did you turn the crankshaft? No way it should ever hit just by turning if it wasn't hitting before that point. Turn it backwards with a worn or loose chain? Yeah, it could hit.

I turned it clockwise, but had to to do it backward once or twice and for a short magnitude to give me enough force to pass this hard point
It was so hard to pass that my wrench was totally stuck, I couldn't turn anymore and the feeling that something was blocking made me investigate

It seems to me very suprising too, so I wonder wether my chain is toasted, wether it's been timed wrong, or unsynchronised after a while, or do my valve adjustment could have caused issues, which I doubt. I must precise that none of the measurment were right and I proceeded to 0.08mm for the intake and 0.18mm for the exhaust

Could you tell me if I remove the chain link, realign both cranckshaft and camshaft, it will be correct ?

[Figoulu]

Additionally I removed the 6th cylinder rocker arms and everything turns smoothly. There is confirmation that something is wrong with this cylinder. In case of a misalignment why only on the 6th ?

[Figoulu]

The alignement pictures

[Figoulu]

Marks are not mine. It’s about 8deg before TDC

[Figoulu]

Here is the print of the valve over the piston head…

[Benz Dr.]

Your camshaft and crankshaft are not in time with each other. Turn your camshaft back one tooth and then you should be fine.

[Figoulu]

Your camshaft and crankshaft are not in time with each other. Turn your camshaft back one tooth and then you should be fine.

Thanks for your answer, this is what I thought.
What's the best way to achieve the correction ?
Using the removable link or remove the chain tensioner ?

[stickandrudderman]

1st, you should concentrate on the crankshaft marks first. Turn the crankshaft clockwise to "0" and then check the camshaft, not the other way around. Common practice is that the camshaft mark should either be aligned with the mark on the bearing or not quite reached it. If it has passed the marker then it is advanced and must be rectified. Slightly retarded is acceptable.
As Dan says, it looks like your cam timing is advanced one tooth so you'll need to remove the chain tensioner and adjust.
I prefer to remove the bolt that secures the sprocket to the cam rather than split the chain simply because if you drop the bolt you can simply pick it up again. If you drop the split link then there's the potential for disaster......

[Figoulu]

1st, you should concentrate on the crankshaft marks first. Turn the crankshaft clockwise to "0" and then check the camshaft, not the other way around. Common practice is that the camshaft mark should either be aligned with the mark on the bearing or not quite reached it. If it has passed the marker then it is advanced and must be rectified. Slightly retarded is acceptable.
As Dan says, it looks like your cam timing is advanced one tooth so you'll need to remove the chain tensioner and adjust.
I prefer to remove the bolt that secures the sprocket to the cam rather than split the chain simply because if you drop the bolt you can simply pick it up again. If you drop the split link then there's the potential for disaster......

Useful intervention 👍👍👍
Thanks
I anticipated the risk of dropping the chain’s removable link, however removing the chain tensioner means to re pressure it with oil which i need to understand the way it works…
I won’t go for removing the bolt of the camshaft although it’s a rather good idea👍👍👍

[Pawel66]

There was a good piece of advise to stick clothes in the openings of the bottom part of the chain galley to prevent small parts being dropped there.

Pre-tensioning of the tensioner is not difficult and was explained on the Forum: pour some oil in its little "basin" and press its arm with a large screwdriver till it becomes "stiff".

I think the good idea is to check if the chain should be replaced or not.

I would also use new clips for the chain - the two clips arrangement, not the one clip. Making sure their orientation is correct.

It may turn out your chain has pressed connecting link - then it becomes a bit of an issue...