To be fair, that may have been due to the availability of tetraethyl lead as a knock suppressant. No longer available.
Ethanol as a knock suppressant seems credible to me. The Offenhauser engines of auto racing fame had compression ratios of 15:1 and were fueled with methanol. Not the same, but chemically related. (Methanol vapor is 5 times more toxic than ethanol vapor, however.)
Well, my show car Cudas aren’t high compression, nor are they soft valve seats that need lead additive. They both run on ethanol free and are void of knocks.
You don't get knocks with low compression. But that was what the recommended octane ratings were all about (low-test and high-test). You couldn't make the higher octane ratings without tetraethyl lead. Now, with supercharged/turbocharged engines, the compression ratio is effectively high and some kind of knock suppression is required. (Lead plate-out on valve seats was a discovery after the fact.)
To be fair, that may have been due to the availability of tetraethyl lead as a knock suppressant. No longer available.
Ethanol as a knock suppressant seems credible to me. The Offenhauser engines of auto racing fame had compression ratios of 15:1 and were fueled with methanol. Not the same, but chemically related. (Methanol vapor is 5 times more toxic than ethanol vapor, however.)
Well, my show car Cudas aren’t high compression, nor are they soft valve seats that need lead additive. They both run on ethanol free and are void of knocks.
You don't get knocks with low compression. But that was what the recommended octane ratings were all about (low-test and high-test). You couldn't make the higher octane ratings without tetraethyl lead. Now, with supercharged/turbocharged engines, the compression ratio is effectively high and some kind of knock suppression is required. (Lead plate-out on valve seats was a discovery after the fact.)