Had this annoying little noise begin and sure enough it was coming from the rocker area, it isn't as light as a big clearance tappet 'tap' but a slightly deeper chatter.

I did notice upon reassembly some weeks ago that one or two of the arms had a hesitation but I didn't think it would have affected things as it was only slight.

Could the hesitation have worsened and started making this chattering noise due to all the friction?

Noise is not audible at idle rpm but it is most audible up the rev and down the rev (carbs get too loud to hear anything between the rev up and rev down).

Check that oilways clear.

Yeah oiling nicely, all along the rocker shaft.

That's why I'm sorta asking if the stubborn rocker arm would even make any noise if it's getting lubricated?

Or if there are any other noises that could be caused by another component?

One of the rocker assy bolts pulled it's thread out and the rocker shaft now flexing?

All studs are nice and tight and the threads were all good when I looked at the head.

It can't be the valve head sticking it to the piston crown because I did all my measurements and it was all good so I'm a little stumped.

Has to be a rocker arm, I'll try another assembly tomorrow and I'll check all the springs and retainers while I'm at it. Hopefully that'll sort it out.

Another thought, very highly unlikely but have seen it once before and it made the same sound - loose valve seat?

GL with the investigation..

#OOPS#. Yeah that might be true, funnily enough I have had an issue with the carbs that has started at the same time (could be to do with a loose intake valve seat) but I also found that the linkages had moved so I determined the out of sync carbs to be that issue. Too many variables. I was thinking the noise had coincided with the carbs playing up but like I said the linkages were loose on one and the performance was like the carbs were out of balance.

Will do a compression test as well to check how it's all going. Is there any other way to check the loose valve seat or should I just pull the head off.

Thanks for that Dean.

I would say you would need to pull the head off to find a loose seat but I wouldn't worry about it too much, much more likely to be anything else. Like I said, have only seen it once before and it was on a iron headed Toyota diesel that had done a billion k's.

Check everything out, make sure it is all adjusted OK etc. I reckon you are probably onto it with the rockers or maybe a spring?

Yeah I might be a bit paranoid too, but I can definitely hear something. I didn't check the spring pressures but they felt nice and tight when I was assembling the head. Will know by tomorrow, might even do a comp test tonight if the bloody rain stops.

Hasn't been the best day for my Datsuns. Just busted two blokes hanging round my other Datto reckoning they were just looking at it, but WTF were they doing looking at it in the dark? Had the cover off and everything but like I said it's pitch black....

is it by any chance bent valve stem/worn valve guide?