Reply to "Toluene as an Octane Enhancement"

jd3Member

I've got a '71 911 with a hi compression AL head 327 SBC. Not sure what the CR is, but it detonates and overheats on pump 93 octane here near sea level.

It takes 2 gallons of toluene per tankful to stop detonation. 1 gallon of AV gas (or leaded race gas) stops detonation, and makes better power. The last time I bought toluene, the cost was similar to AV gas, so using AV gas in my situation is a no brainer.

If you want to buy toluene, the best price I found was buying 5 gal at a time at a big paint store.

Note that even "low lead" AV gas has a decent amount of lead in it, which really helps octane and lubricates valves. However, my car is carbureted, and lead would damage O2 sensors in an EFI application. Good luck.

Jack

P.S. The cheapest price I just found in an online search for 5 gal toluene is $10 a gallon. That is a lot higher than the ~$5 a gallon for 100LL AV gas right now.
Also note, what I wrote above is just my experience, with this car only, etc. YMMV.

11/19/162:34 PM

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