fla1976

What changes would be required to change an alcohol carb back to a gas carb? It is a Barry Grant 750 that is set up for roundy-round racing. I am sure it would have to change to smaller jets but what else to make it right. Appreciate any input on this.

dparker

Going to alcohol is much easier. Because your drilling out orifices to make them larger. To go back to gas you'll have to find a way to make the holes that were drilled out smaller. It might be able to be done, but I think you would be money ahead to sell the alcohol carb and buy a gas carb.JMO

TopspeedLowet

Air bleeds will be small currently relative to gasoline with alcohol to increase the flow and need to be larger for gas. Needle and seats will be huge for alcohol and usually no vitton for sealing and should be changed to vitton type needles with .130" for 1100+HP stuff and .120" for 1000 and less. Stock seats are .110 for gasoline carbs. This is the basic changes that make a carb able to use alcohol and will let you tune from there. The jets will be two digit numbers for gasoline too. Alcohol jets are usually starting out in the 110 range. If the air bleeds are not screw in type then parker has a point about the effort to go backwards, and in the intermediate circuit's if it has one.
Bruce