It could be a flat spot on cam lobe or some wear in the bits above as in pic below
Round roller , the tappet guide steel ( this is located by bolts in block seen in second pic ) if bolt was loose it could move when not supposed to
The the brass sliding part where the bottom of push rod sits could be damaged
Are you sure no head leaks around cylinder head joint
I bought a new rocker from turners on my rebuild and that had discolouration , I think this will be due to the heat treatment for hardening the rocker
I wonder, could it be the rocker shaft itself in trouble? The series engine has a good strong pedestal for the rocker, but there are clamp bolts to tighten the shaft.
Pop the rocker cover off again, and check the 5 pedestals. Make sure the shaft isn't broken or loose.
Depending how far you want to go the shaft could be dismantled carefully to check for wear
May be possible to detect smoothness of cams with finger on end of pushrod while rotating engine by hand
good afternoon,the componant with the evidence of past removed corrosion is the 'Rocker shaft support bracket',the front one,
The corrosion was where it meets the head casting.
Thanks
Ryn
Good morning,
It went into the garage for a safety check on monday and the good news was that the servo 11" tls brakes, parabolic suspension,steering and the rest are all working as they should,
Thanks to all for the advice,
Ryn.