does anyone know where I can get some information on octane needs for performance engines? I bought an LT1 that has about 570 n/a at flywheel with 3.5 crank and 12.8:1 compression. I was told it was built for alcohol, but I am wanting to make it more streetable. I need info, so I can figure out how I can run on pump gas.

 

Octane requirements are determined largely by "dynamic compression ratio", not be static compression ratio. Do a "search" an "octane" and "DCR" and you should be able to find discussions of the DCR limits for various types of fuel.

 

You'll probably have to change some gaskets as well.

 

yeah, I know the heagaskets are .018, so I have some room there to lower the compression.

 

I have done some searches.. and have found a few articles that, in summation, state to try different octanes until pre-detonation stops... then adjust the power with timing.