Is 93 octane enough?
Melting Slicks
Joined: Dec 2000
Posts: 2,198
Likes: 2
From: Eastern Connecticut
Re: Is 93 octane enough? (td-machines)
Do you have an owners manual? The one for my 73, which is only 8.5:1 compression, requires 91 octane. Do you hear detonation (pinging) under load? You can retard the spark a little if you are on the edge, or fool with the vacuum advance if you are handy with a distributor. Look at the plugs, are the electrodes eaten away by preignition? Is the porcelain broken? If all of the answers are "no" then 93 octane is probably OK. FWIW, I used 93 in my 69 with the same motor, and didn't have any problem, but I was young and naive then, too. Joe
Team Owner
Joined: Jul 2001
Posts: 182,997
Likes: 88
From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
Re: Is 93 octane enough? (td-machines)
I think that you shouldn't have any problem with a 10.25 : 1 compression.
The 383 stroker engine on my previous 69 Vette had a 10.8 : 1 compression and I ran with 93 octane + 2 bottles of octane boost (108). Sometimes I ran without octane boost and the engine would run ok. However - everytime I used Chevron gas - the engine started dieseling. This must have something to do with the additives they add to their gas...
Olivier
The 383 stroker engine on my previous 69 Vette had a 10.8 : 1 compression and I ran with 93 octane + 2 bottles of octane boost (108). Sometimes I ran without octane boost and the engine would run ok. However - everytime I used Chevron gas - the engine started dieseling. This must have something to do with the additives they add to their gas...
Olivier
C6 the C5 of tomorrow
Joined: Nov 2000
Posts: 6,665
Likes: 2
From: Twin Cities Minnesota
Re: Is 93 octane enough? (GrandSportC3)
Remember this...
1. Any pining is bad
2. Older engines require more octane than new engines due to their design, so 93 may not be enough...
1. Any pining is bad
2. Older engines require more octane than new engines due to their design, so 93 may not be enough...
Pro
Joined: Aug 2000
Posts: 708
Likes: 21
From: Montrose CA
Re: Is 93 octane enough? (427V8)
Its all relative... The 93 will be enough with the timing cranked back so far you leave horsepower on the table... keep the timing up, dump in the octane booster, and let that baby fly!!! I also bet there are situational tuning tricks like making the high speed mixture a little richer, using cooler plugs, or even something like ceramic coating the internals in the combustion chamber to spread out the heat.
Racer
Joined: Aug 2001
Posts: 356
Likes: 0
From: Glacier County mt
Re: Is 93 octane enough? (td-machines)
If you ping or run on use Lead Supreme 130 by Kemco Oil in Lehi Utah.
It is almost completely tetraethyl lead. Look at their website:
http://www.kemcooil.com
:cool:
It is almost completely tetraethyl lead. Look at their website:
http://www.kemcooil.com
:cool:
