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Old 05-28-2006, 05:26 PM
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xntrik xntrik is offline
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Quote:
Originally Posted by al37ford
The initial cost of a roller retrofit can be cheaper than the standard flat. After THREE wiped out camshafts, 2 Crane & a Comp, we bench broke in the FOURTH rebuild and found the lifters spun properly using stock chevy springs but going back to the stock Edelbrock the lifters did NOT spin which translates to a quick lobe wipe out! Several reasons found , including the new environmental oil composition but the main reason apparently was that the lifter bores were not perfectly square with the cam surfaces. Likely a bad run at the factory! Worked ok with stock stuff but NOT with higher performance. I haven't read it yet but am told the June issue of HotRod mag. has an article addressing same.


Good article.

SBC are notorious for lifter bore wear and dumping oil pressure out the lifter bores. More than .0015 is asking for trouble. On race prep engines we rebored the lifter holes. New lifters are available that have lubrication holes in the lifter face. Chevy blocks of the 70s-90s were often horrible on lifter bore angles and even cylinder bore angles. I have seen 350 block cylinder bores that were more than .050 out of square with the crankshaft. Makes me wonder how they ran 100,000 miles. I did one that was so bad that it could not even be bored .060 over to correct the angle so it was junk.

Could be lifter face angles, too. CompCams has now adjusted its cam lobe face angle to allow for more lifter rotation with heavier springs, this to assist in the reduced lubricity of the modern oils. Use Rotella T, racing oil, or synthetic.
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