Swift_Striker

After my old engine failed its rod bearings, I got a replacement lower mileage engine and ran it for a season of autocross. I was short on time so I just popped it in and ran it. I was told it had the retainers updated before I ran it for the season and I trusted in that.

This year I popped off the valve cover to do my valve adjustment and noticed the cam looks to have some wear. I can't catch my fingernails on anything but I can feel a slight roughness. most of the valves were within spec, a couple were slightly loose

and a couple were slightly tight.

When I compare it to the cam lobes on my blown engine, it looks as though my old cam was wearing better. I'm now debating whether I should put my old cam in this engine, though with the rod bearing failure, I'm not sure how the cam journals look yet. Another note is I had some silver mush stuck to the oil pan magnet when doing the oil change which I believe seems like wear from the cam lobes.

I forgot to inspect the retainers to see if they are new or if they are failed, that's my first step tonight.

Old Cams from spun bearing engine

Cams from engine in car

Worst Lobe, can't feel the mark though. Exhaust low lift lobe.




Metal from magnetic drain plug

Second opinions? Leave well enough alone, run it, re-check wear next season?

B serious

Check to make sure the retainers aren't cracked. Use an inspection mirror or camera to look at the valve facing side.

noodels

What oil is being used,looks like they are getting too hot.

aaronyuri

And how often is it being changed? It should be quite often if you are doing any kind of circuit usage - every visit or at least every other.

Billman250

Nothing wrong there, they are normal.

Slowcrash_101

The dark marks are indicative of burnishing. Like Billman said you're fine. The burnishing is caused by the metal folding at a microscopic level in one direction only. Since the cams only rotate in one direction some burnishing is normal, especially on the exhaust side.

Burnishing (metal) - Wikipedia

Swift_Striker

Thanks for the extra opinions all.

I run Castrol Edge10W30 Full Synthetic. I don't lap it, just 8 autocross days per year. It's changed once per year (about 2000mi)

I checked the retainers and confirmed the intakes are AP2 retainers and the exhaust are all fine. (all look like below)




Valves adjusted and ready for another year!

AaronCompNetSys

Just in case you didn't know, these photos are of the wrong side, if you are looking for cracks.
https://www.s2ki.com/forums/californ...ainers-847563/

Swift_Striker

Appreciate it, but the non invasive procedure is to check if the keepers had recessed into the retainers on AP1 retainers (Mine are all flush as seen on the blue spring exhaust). AP2 keepers sit a bit lower due to their design, which I was able to confirm the intake side had been swapped in my car with the mirror as well.

windhund116

Maybe, looking for dropped retainer locks, due to cracked retainers?