[carbking]

"Expert"

"X" - from 7th grade algebra - an unknown
"Spurt" - a drip under pressure

"Expert" - an unknown drip under pressure

Various fuels have different energy content (dig out your Handbook of Chemistry and Physics). Gasoline is accepted to contain 117,600 BTU/gallon. Ethanol, methanol, and other alcohols contain less energy; but under favorable conditions (including the proper mixture) may make more power due to other properties. Any mixture of these fuels WILL require carburetor recalibration.

Suggestion - first calibrate the carburetor on race fuel, you now have a baseline.

It has been our experience that; once the carburetor has been calibrated for race fuel, A GOOD STARTING POINT FOR ALCOHOL IS TO INCREASE THE EFFECTIVE METERING AREA BY A FACTORY OF 2.2.

Example: if a metering jet of diameter 0.100 were found to be the proper calibration on race fuel; then calculating the area would give 0.00785. 2.2 x 0.00785 = 0.0173. The area of a jet 0.149 diameter has an area of 0.0174. This would be a good starting point.

If the carburetor in question uses metering rods (Carter WCFB, AFB, TQ; Rochester Q-Jet); remember that the effective metering area is the area of the jet less the dynamic area of the rod.

Using a mixture of race fuel and either ethanol or methanol would require a different conversion factor. The example is just an example.

You probably already know this; but if using a methanol based fuel, it is important to drain the carburetor following use, and flush the carburetor with race fuel (unless the area touched by the methanol is nickel-plated or you enjoy replacing carburetors). Much as I detest saying the dreaded phrase , fuel injection is probably the way to go with methanol.

Jon.