new carb size ?

[kenk]

My 3500lb street strip 69 camaro has a Demon 850 mechanical secondary carb. I want to convert to e85. The 460" BBC has 13.0/1 pistons, 610 lift 255 duration cam and 410 gears. Should I consider a smaller, larger, or the same size carb? Thanks for your help.

[jmarksdragster]

If you still drive it on the street stick with the Demon. We did some dyno testing with a 1.500 venturi sleeved RS Demon I converted to run E85, made very good power.

[kenk]

Thank you, sounds like good advice.

[lovehamr]

I've considered the same thing myself and had a few questions.

How much does jetting usually change when going to e85?
How about air bleed changes?
What is the range of CR that you should shoot for?

Thanks, Steve

[jmarksdragster]

You can't just change jetting to go to E85, the metering blocks and boosters need mods in almost all cases to get enough fuel through. Jetting on an 850 will be high 90's to 100 with the appropriate mods to the carb. E85 does not need much emulsion either. And so far we've run up to 14.5 to 1 with no issues.

[lovehamr]

Thanks for the reply Mark, that's exactly what I wanted to know.

Steve