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I'm looking to inspect and potentially swap out my AP1 intake retainers/cotters this weekend. In doing so I came across a thread (https://www.s2ki.com/forums/s2000-un...1077005/page4/) in which devildust had to replace his intake cam because it was etched because his retainers were so bad.
I can't inspect just yet because I don't have access to a garage until the weekend. In case I do have etched/scored cams, a couple questions:
1. If i replace the intake and/or exhaust cam, do i need to replace the cam caps ?
2. If I find a used cam in good condition is that OK or should I stick to new cams?
I'm looking to inspect and potentially swap out my AP1 intake retainers/cotters this weekend. In doing so I came across a thread (https://www.s2ki.com/forums/s2000-un...1077005/page4/) in which devildust had to replace his intake cam because it was etched because his retainers were so bad.
I can't inspect just yet because I don't have access to a garage until the weekend. In case I do have etched/scored cams, a couple questions:
1. If i replace the intake and/or exhaust cam, do i need to replace the cam caps ?
2. If I find a used cam in good condition is that OK or should I stick to new cams?
thanks!
1. Depends, you will probably have to inspect the cam caps for damage. In the thread you linked it was suggested to replace the cam caps.
2. Used cams should be fine as long as the cam caps were removed properly.
For what its worth I have never seen the cams damaged like that in any car that I've worked on.
-It is rare to find camshaft etching damage (retainer raises up on the keepers enough to contact the roller rocker) but it can happen. Even at this catastrophic state, there are no symptoms. Etching damage only occurs during extended use with cracked retainers (upwards of 10k miles)
In over 95% of cases, etching damage occurs at the intake cam lobe, second one from the firewall. You can view it quickly through the oil cap hole
-broken retainers can go undetected for 30k miles with 0 symptoms, then let go instantly (roller rocker will lever the retainer back and forth, until the retainer/cotters/valve tip break off as one solid wedged piece)
-currently at 145k on the track car, original AP1 retainers
-AP2 retainers and cotters will raise the "over-rev damage RPM" to 10700, 1000 RPM over the current retailer split RPM of 9700.