Quote:
Originally posted by speedkillz
When yours broke ...what kink of sound did your engine make?... any help ???
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I did not hear anything loud when it occurred, but afterward it had a ticking like a valve adjusted wrong to 150-200% of its designed clearance. It definitely came and went, even with the car sitting there idling. I was able to localize which valve area it was using careful ears, along with an automotive stethoscope; mine was #1 intake. I still feel lucky that it was exactly the one I thought I was hearing. with the rocker arm and shaft out the spring was clearly broken (seen with a mirror), the outer had broken all the way through and was in two pieces. I think you should try to listen carefully with a stethoscope to see where it is coming from, then pull that rocker and shaft.
Quote:
Originally posted by wholberg
My own opinion is that valve springs are subject to conflicting accelerations at high revs.
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I buy this whole argument, but I would think a stock SC cam at even 7300rpm would be relatively gentle, compared to people I know using RSR sprint cams with stock valve springs at 8000 or 8500. However, I can certainly see why an over-rev might cause this condition in a nasty way.
hopefully I just found a weaker spring than the rest of the lot (knock on wood). I'm sure oil temps of 250 or so don't help a lot.
Thank you, that is helpful, I should have searched for something like that.
Cheers,