Octane rating when mixing Regular gas (93octane) with Racing fuel (110) octane.
- Thread starter bob32268
- Start date
So you understand that if the mix of fuels are equal composition wise what you pasted should be correct. The problem is the poster told us what he was blending and no one can tell him the octane without knowing the exact composition of each fuel being blended.
I give up.
bob32268
Well-Known Member
I believe you're missing the point.... I'm trying to approximate the octane of the gasoline I used back in the 60's when these cars were new....I drove these and other musclecars back in the 60's and early 70's and they ran much better than they do on the junk gas available today... I realize Lead (and lack of) also comes into the question...also I believe that Octane is calculated differently today than in the 60's..... Just trying to get my car to run the best that is possible on what's available for sale today. These "stock 383's" seem to be looked down upon by todays drivers but when new these RR's and Bee's with 383's would really haul ***. They could keep up with the SS Chevelles, GTO's, and others with no problems.
Just run the best ethanol free premium and you will go faster than 1969.
bob32268
Well-Known Member
I'm having a hard time finding ethanol free gas around here (Western Pa.) thats at 93 or above octane rating.....
Just go to a shell station and get the best non ethanol pump gas. You do not need 93 octane. Like Jerry Hall said put it in and run it. If it does not detonate your gold. No sense beating your meat to death on a stump if you do not need to.
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j-c-c-62
Well-Known Member
What you seem to be tying your wagon to is the supposition that the two fuels being mixed interact chemically in some way with each other forming new compounds, and that accounts for the non-simple algebraic nonlinear new calculated octanes you have yet to share. I submit there is no chemical reaction taking place that the OP is considering, nor do the components of these two fuels counter each other in any way. Their effects are additive. This of course assumes the fuels are blendable, and somewhat easy to verify. If the components do not interact to form new compounds, it doesn't matter what the fuel is made of. You are welcome to make a case otherwise, I'm all ears.
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So what you are saying what comes out of a dogs rectum during sex with a giraffe changes the molecular construction and could become gasoline. Is it premium or regular. Just go away JCC. Thousands of moparts agree.
j-c-c-62
Well-Known Member
You hate getting treed is your point?
Well done.
Your Moparts reference is a personal badge of honor BTW.
No I do not. Its just the world, Moparts, and Here would be a better place with out you.
j-c-c-62
Well-Known Member
You are going to make me cry.
Exactly.
33 IMP
Well-Known Member
More octane than necessary will NOT make your 383 run better. If it runs okay on the best premium you can find in your area, then you're gold.
If not, then try some octane booster recommended here, or a bit of added avgas or race gas. You probably won't have to mix 50/50. A couple gallons of 110 or avgas should solve it.
I can run straight california catpee 91 in a 10.5 to one, iron head 440, but since I now have access to avgas, I run about a 1/3 tank of avgas with the 91.
If not, then try some octane booster recommended here, or a bit of added avgas or race gas. You probably won't have to mix 50/50. A couple gallons of 110 or avgas should solve it.
I can run straight california catpee 91 in a 10.5 to one, iron head 440, but since I now have access to avgas, I run about a 1/3 tank of avgas with the 91.
j-c-c-62
Well-Known Member
As others have posted, just find a station (better yet, a network of stations in your area) that offer ethanol-free gas.
Preferably 93 alky-free.
Adjust timing so it just barely doesn't detonate (knock) on it and you're golden - but that "alcohol-free" part matters
more than you'd think.
Here locally, the difference between the 93 ethanol blend and 93 no alky is readily apparent in Fred; he runs noticeably
better on the no-alky stuff and gets further on a gallon, too.
(Hint: Check with the closest Co-op; they sometimes offer alcohol-free).
BTW, this is "Fred" on the good stuff:
Preferably 93 alky-free.
Adjust timing so it just barely doesn't detonate (knock) on it and you're golden - but that "alcohol-free" part matters
more than you'd think.
Here locally, the difference between the 93 ethanol blend and 93 no alky is readily apparent in Fred; he runs noticeably
better on the no-alky stuff and gets further on a gallon, too.
(Hint: Check with the closest Co-op; they sometimes offer alcohol-free).
BTW, this is "Fred" on the good stuff:
Non-oxy premium is easy to find around here, and the GTX will run okay on it if I’m not pushing it too hard. Ambient temperature also seems to be a factor. If I mix it 50/50 with Sunoco 110 I can run it as hard as I want with no detonation.
Edited to add, iron head 440 with too much CR…
Edited to add, iron head 440 with too much CR…
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