There is a gas station a couple miles from me that sells race gas. It's pricy, $9 something a gallon. Once wile I was there a guy filled his 427 mid 60's corevette. I bet he dropped $150 for a full tank. I hear too high of octane is not good for your motor. Any truth to that statement?
He probably had compression ratio of 12 or maybe even 13:1. (Unless he was a bafoon who didn't know what he was doing ...
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The higher the octane, the slower (and cooler) it burns. So you need to compress it more.
Lower octane fuel will burn quicker (and more easily) under less compression.
A car set-up for racing level octane (100+) and appropriate timing would run into more trouble with lower octane fuel - primarily, pre-detonation. Destructive detonation possibly.
A moderate compression ratio engine (9-10:1) timed for say 93 octane with 110+ race gas in it will not detonate all the fuel completely. Maybe 10-11:1 you could run 100 octane racing fuel.
Will it hurt it or is it not good? I'm not sure or knowledgeable enough. Not fully burning the fuel can't be great over a longer period of time.