Cam follower pitting

[Colin Wilks]

I had some newly reground cam followers (std 3/8") from a supplier. The one on the left is pitted as shown. The one on the right I consider good, although when I blow the photo up it too has one small pit.

I have had the camshaft refreshed by Paul Bonewell, so don't want to spoil the ship for a ha'porth of tar, but am I being too fussy?

Is it possible the grind has gone through the surface hardening? It is definitely a few thou shorter than its neighbour.

[Ruairidh Dunford]

I would not use those Colin - ask Paul to do you some that suit his cam work.

[Tony Betts]

Coming soon.

Early next year.

NEW cam followers.

standard 3/8 and sports 3/4

Picture shows a new one tested in the guide, new outside the guide. And a used one on the right.

   

[Ruairidh Dunford]

Very nice Tony!

[Colin Wilks]

Cheers Ruairidh. Do you consider the one on the left scrap, or is it worth a regrind? I am not sure if the followers are fully hardened or just surface hardened, if the latter is it practical to harden it again by heating and quenching? I am not aware of anyone making new ones.

PS Tony just answered my last point!

[Steve Jones]

Great news, Tony. Something that's been needed for some time. Picking 8 good ones from the pile of used ones has become more and more difficult as time's gone on.

Steve

[Paul N-M]

Bucket job. If used will wreck cam.

[Ruairidh Dunford]

Colin - go with Tony's.

[Chris KC]

I think the pocketing on the follower will cause lubrication problems and accelerated wear so yes please bin it or at least grind until the pitting disappears.

As for hardening, I have no clue what the original spec was but I'm not aware that anyone hardens (or re-hardens) after re-profiling?

p.s. Those look smart Tony!

[Tony Betts]

thank you all.

its a long process, cad drawings, metal quality checks.

this is the samples stage, which has been checked and OK`d

and now the final stage, whaiting for manufacturers and delivery.

notice we have also done new tappets and locking nut.

the tappets are machined from scratch, rather than cutting corners. machining down high tensil bolts.

strange one with colin`s followers.

i supplied them as good used, the pitting is under the surface. and has come through in grinding.

ive seen it before.

original parts are very high quality, but every now and again you find the incusions when reconditioning.

tony