Quote:
Originally Posted by '68OrangeSunshine
Step'67: what caused the lobe wiping of your cam?
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The #8 exhaust lifter began chattering. Upon disassembly, the lifter was dished while the cam lobe had rounded and began to grind off. From other's experience, it doesn't seem typical that a cam lobe fails a couple years after initial break-in due to material defects. After digging into Amzoil's product data sheets, and user posted Blackstone lab reports, I'm leaning towards it being caused by my oil choice. According to the lab analysis, the Amzoil Premium Protection line I was using carries a zinc concentration of approximately 1000ppm (around 200ppm more than the current oils on the market). However, for a hotter than stock cam with fast lift rates and high lift/duration, an oil with 1200-1400ppm is recommended by Amzoil. This is where their ZRod and higher race oils fall, and why I'm switching to it to hopefully prevent it from happening again.