Who can re - grind/coat/repair - damaged S3 Cams

[trypcil]

I've, in my possession a set of S3 cams. They are marked up at the journals and I don't really want to put them on my Cal Sprint like that. The argument is to just buy new of course. That is an option but not the point of this thread. I explored this earlier and found someone in Norcal(when I was living there) that advised against welding and machining and was saying his nickel something or other process was better! Anyway I was wondering what the options were to get these cams serviceable again, maybe what to look out for even - and then what is the journal diameter and does that matter and then perhaps, if it does, in what way? ***, I know nowt about cams, anyone?!

[LaneSplitter]

Just a thought, but have you tried talking to a place that grinds/regrinds cams? I've heard of cams being ground or rebuilt for cars and I would think that the process would be the same.

Glenn

[Roden]

The journal diameter not only matters but is critical! When they are installed into the head and the caps are torqued down, the diameter of the journals and the bore diameter of the bearings is going to determine the clearance through which oil circulates. Too tight and no lube gets through and you have a seizure and wreckage on your hands. Too loose and the cams will rattle around, and damage will again be the result.

From the book, journal diameter (except outrigger) is 22.90-22.93mm.
Outrigger journal (cam chain end) 22.923-22.936mm.
Bearing bore diameter 23.000-23.021mm.
Oil Clearance 0.12mm maximum.

The oil clearance can be checked with Plastigauge but really, if your cams and bearing bores are within those specs, you should be fine.

Journals can be repaired by a good machine shop by welding or better still, a metal spraying technique such as nickel and re-machined to size.

After any such operation, they would also check the cams for true, i.e. no run out.

We should be able to find these people with good old google!

Cheers,

Roden