Fuel Reference Needed

[MadFord]

The engine's comp. ratio will be between 11.5:1 and 11.7:1. Trying to prevent detonation. What octane fuel should I run?

[Eroq]

prolly 110...    91 at a bare minimum i'd say

[betterbeaters]

you will need more than 93 I would guess 100-110 would work good. i am 12.5 to 1 and I have to run 110

[Boggen Joe]

You have to check your cylinder psi. That's pretty much how to tell
200  - 215psi. 108-110 oct
215 up 112+ oct
180-200 93 and race mix 50/50
170-180  93 oct
It's just a guide line

[marshall]

I would mix premium and 110

[xjs3667]

im goin with 100-110 on this one    you could go lower say around 89-91  and add some meth/ alcohol  injection

[Jjay78]

premium is really only good for up to about 10.5 to 1 with aluminum heads and about 10 to 1 with iron heads, more than that and you really should run 110untill you get to about 13 to 1 then you need to step up to 114....you can make the engine run on lower fuels but you'll be throwing away power by doing so

[4x4xdodgeman]

I have question what dose the material of the heads have to do with what gas to run??

[marshall]

I have question what dose the material of the heads have to do with what gas to run??

aluminum is less prone to detonation, the reason for adding octane

[Jjay78]

aluminum disipates heat a lot faster than iron does so you can run higher compresion before the residual heat from the last ignition cycle in combination with the heat from the compressing gas mixture hits a high enough tempeture to ignite the gas before the plug fires...