w00t692

Exactly what i thought when i saw s2000maniacs pictures.

I see absolutely no abnormal cam wear in his pictures, i don't see how you guys can mistake how it looks. smooth polished look = normal, rough appearance = NOT normal

Now the other guys cams, they're effed, ground down from contact with retainers as said.

starchland

I agree cams look fine, except one cam in the first picture post, but that could just be light playing tricks.

hrpfg2

hey, you seems pretty smart about this. can you point out the differences between s2000maniacs and mine?
and cams aren't in contact with retainers btw. no body said anything about cams being in contact with retainers.
"as said" by billman250 "The retainer is rubbing on the roller rocker, and the hardened metal powder is etching the camshaft."


I am sorry but if you are only posting to make yourself seems knowledgeable, please don't post.
you are only misleading people.
Thank you for trying to help.

Billman250

left lobe=High lift lobe in perfect condition. the lobe on the right has been etched. note the grey sandblasted appearance in the middle of the lobe.

You will also likely need a roller rocker. They are purchased as a 3 piece matched set and cannot be split up. When you look at the bottom of the rocker, you will see two triangle shaped impressions due to contact with the retainer.

Billman250

90% of the time, you will not find an etched camshaft. So it CANNOT be used as a way to check for broken retainers. But if the cam is etched, you can be sure the retainer has been broken for a very long time (up to 30k miles).

So if you over-rev, then pull your cover and find an etched cam, it was not caused by the over-rev you just made. It was likely cause years ago or by a previous owner.

This is the stage where the contacting rocker levers the retainer and keepers sideways until it snaps the head of the valve off, dropping the valve into the cylinder. The valve and keepers never have a chance to pull completely THROUGH the retainer.

Keep in mind at this stage of damage, with a grinding roller and destruction around the corner, NO SYMPTOMS WILL SHOW. Not even the slightest noise.

hrpfg2 you are lucky man

speedjunky01

wow pulled the cover just in time

take the cam to a machine shop they might just be able to micropolish it out, even though its base circle will be a tad smaller you will be able to compensate when you do a valve lash adjustment.

JohnsS2000

What Billman says you can engrave in rock and call it LAW.

I drove my car after a slight overrev(downshifting off the interstate).. What happened was;
getting off the interstate, downshifted and began letting off the clutch, as the RPMs began to climb, I realized I was going too fast for a 2nd gear downshift and reengaged the clutch. The momentum the engine had already had bounced it over 9K for 1/4 a second. It only took a super breif over rev. No CEL, no missing, car ran perfect for 18 months before the CEL came on. about 18 months & 9000 miles later and the CEL came on. Took the car to as local shop(in Tampa/St Pete) for repair. Before taking it to the shop the compression was fine in all 4 cylinders, leakdown was good in all 4 also. CEL was a miss fire in multiple cylinders. Since the only issue I ever encountdered was this over rev from 18 months before, thats what I figured was the culprit. Sure enough, pulled the head to find 6 bent valves. Bent very very slightly but bent none the less. Valves have been replaced with new SS ones and the retainers upgraded to AP2 and the car has been running flawlessly. 1775 miles to and from the dragon as well as the driving before and during(hard miles in the Smokies) with no issues.

hrpfg2

thank you for sharing that picture with us billman250.
and all the helpful info.

indeed I do feel very lucky to find out before a valve is dropped.

s2000maniac

Dammit now I think I might have some bent valves

: cry:

w00t692

hey, you seems pretty smart about this. can you point out the differences between s2000maniacs and mine?
and cams aren't in contact with retainers btw. no body said anything about cams being in contact with retainers.
"as said" by billman250 "The retainer is rubbing on the roller rocker, and the hardened metal powder is etching the camshaft."


I am sorry but if you are only posting to make yourself seems knowledgeable, please don't post.
you are only misleading people.
Thank you for trying to help.
[/quote]

Sorry, i didn't mean that they were contacting the retainers, even my dumb ass should've known better than to say this. But you should be able to tell the difference between a properly wearing camshaft... and one that is not. I've seen pitted aftermarket camshafts and they look similar to this, except sometimes it is so extreme that the hardened rocker roller grinds the lobe down to nothing with the help of the camshaft material grinding away due to an improperly heat treated camshaft.

normal = smooth polished appearance
abnormal = pitted "sandblasted" effect as billman said.