Can you look at photos of my cam lobes and tell me if they are ok? Thanks

B+Bogus said:

I'm quite surprised by the range of replies - all the way from 'it's fine', to 'it's knackered'.
I've already said 'it's fine' on the basis that looking at the witness mark from where followers run there's no discernible step between the worn/unworn part of the cam.
Yes, it shows some signs of wear, but nothing which would impact performance or longevity IMHO, and entirely consistent with all the other 750 cams I've seen.
The late 850 cams I've changed have clearly worn through whatever surface treatment was (or wasn't) applied and they're unquestionably knackered.

I'm curious to know what pass/fail criteria others are applying.

Click to expand...

Stephen Hill said:

Whenever I see a cam lobe with a rough finish, as DennisMo shows in his photos, I wonder if the cam is redeemable.
For example, if the cam lobe is within specs in terms of lift, but only showing a rough surface finish, could it be made good with basic shop techniques?
Let's say it starts within .002 of specs at the tip of the lobe, and ends up smooth and blended at .005 below spec. Personally I don't see a problem with this. The difference could easily be covered by the variation in valve lash we all run.
And it aligns with my basic value set where I prefer to repair rather than toss and buy new, where it makes practical sense.

I'd rather not get into a discussion about going through a hard surfacing material, because as any cam grinder will tell you, that is mostly nonsense. And I am talking minimal amounts of material removal. So IMHO even lobe geometry is a bit of a red herring.

I appreciate that this is difficult to discuss without the actual cam in hand, or some agreement on specific skills and tools available to do the job.

Flame on.

Click to expand...