Don Terrill’s Speed-Talk

I would like to know how can I change over from race fuel to alcohol on my sbc 400

Depends on the application mainly. It can be carb or injection but both are specific specialized fuel systems. A dirt car set up is different than a drag race system. Just give a more specific application to get a more specific answer.

Drag racing what do I need to do first time for me going alcohol it's carburator

You can modify your existing carb for alcohol/methanol. It requires extensive changes in all the metering circuits as you will need more flow across range, and really is a job best left for someone that knows what they are doing. Depending on your application, you could even need dual needles and seats for the float bowl. Personally I would recommend trading your gas carb for a purpose built one.
Fuel delivery requirements are very application specific also, you could get away with a generic alcohol compatible pump, or need a belt driven one with a vacuum bypass regulator.

Not just the metering blocks, the boosters have to be changed to ones with larger passages. Unless you have the tools to do your own work you are better off buying an alky built carb.

Final thing I would like to know what the cheapest way to go alcohol or race fuel

Dump it in the tank is the cheapest....but it don't work very well. Alky...no aluminum fuel cells. What fuel system do you have now?

make sure the tank vent is large enough as the fuel must leave the tank at a faster rate than with gasoline so the air must get into the tank faster.

If you want to switch to alky find a reputable carb builder (or fuel injection provider) and get EVERYTHING from them. Forget all the different advice you'll receive here. The advice here will probably all be good, but won't necessarily work together. I could list some people/companies to call but I'm sure I'd leave some good ones off the list, and that wouldn't be fair.

cgarb wrote:Dump it in the tank is the cheapest....but it don't work very well. Alky...no aluminum fuel cells. What fuel system do you have now?

An aluminum tank can work just fine if its been anodized. Some fuel cell foam isn't compatible with methanol so that's something to check.

My advice to anyone with methanol is replace your aluminum fuel line fitting every couple of years. They are anodized but you would be surprised how ate up they will be after a couple years. I left mine go for about 6 years and when I bought new hose planning on using the fittings over, when I pulled them off the old hose they were in very poor shape. Some of the tapered ends were corroded back to the threads. So anodized tanks may be ok, myself the less aluminum components I have the better.

cgarb wrote:My advice to anyone with methanol is replace your aluminum fuel line fitting every couple of years. They are anodized but you would be surprised how ate up they will be after a couple years. I left mine go for about 6 years and when I bought new hose planning on using the fittings over, when I pulled them off the old hose they were in very poor shape. Some of the tapered ends were corroded back to the threads. So anodized tanks may be ok, myself the less aluminum components I have the better.

The problem is moisture getting into the fuel. If it is run very often and fresh fuel is always going through the system corrosion isn't a problem.

when my customers ran alky with a carb I advised them to flush the system with gasoline after each night of racing and have a shut off valve on the fuel tank vent to keep out moisture . when I rebuilt their carbs I could tell who did not listen.