Thread: SR20 Camshaft Issue: Looking for some input

So I got all of my head stuff back today, and I noticed something I've missed when I took everything apart. On the #4 lobe of my exhaust cam, one edge seems to be slightly higher (.001"-.002" is the best I can measure atm) as if the rest of the lobe was worn down but not that edge maybe? These cams have at most 3k miles on them between two failed motor builds (sad I know). They haven't been run since I sent them out for WPC treatment and they were used for adjusting the lash between the rocker and cam by Port Flow Design.








Here you can see that the rocker arm (if sitting in the middle) rides right on the edge. If you slide the rocker arm across the lobe, it does catch on the lip of the groove.



I'm not sure if I should run the cam or not. Part of me thinks that if the rocker arm doesn't hit it, I should be fine. I'm mainly worried about rocker arm tilt. Any constructive input would be greatly appreciated!

That's a pretty common wear pattern, but usually at much higher miles. If you're seeing that at 3k I'd be concerned.

but on second thought I'd probably just run them.

I had premature wear due to rocker tilt and bad valve guides, which is all fixed now, but yeah... lol

Pop the valve cover when you put in fresh oil and make sure you dump it in that area

It definitely didn't have an oiling issue. It was coated with oil every time I popped the cover off.

The acceptable wear limit for cams from the FSM is 0.2mm. It is hard to tell, but yours look to be within spec. I'd run them. I've seen much worse, although I wouldn't run cams much worse than that.

Let me find a link for you...

Edit: More info. http://www.sr20-forum.com/members-rides/554-benfenner-s-1994-black-se-r-13.html#post284484

Those cams in that link were damaged over a long period of time with not enough lubrication. The ridge went all the way around the lobe so you have to double the amount of wear you think you see, and look to have about four times the wear yours have. They were in rough shape. Not only was the wear an issue but the lobe surface was rough all over. Not terrible, but not something I would run. Yours aren't great, but look to be acceptable.

Are those stock cams? What year engine?

Thanks for the info! The cam is a Tomei Procam 260/12mm lift that's been WPC treated. Which is why i don't want to just polish it down or anything, because then I'd have to spend another $100 getting it re-treated, lol. It's between .02mm and .05mm in height. And the ridge is only on the peak and trailing corner next to the peak of the lobe. On the ramps and constant radius bearing faces, it's fine. The engine is a 93 V.2 Redtop S13 SR20 (same as S13 blacktop head). Solid lifters, supertech springs, ferrea valves, etc etc. Motor will be seeing a lot of boost and a lot of RPM.

I'd run it. Worst than can happen is you get more uneven wear.