try the gas can test

[penny]

Whilst reading an old 1997 copy of national dragster i came across an article from barry grant fuel systems and will attempt to recreate the whole article.By trying the gas can test you may improve your E.T.s, you,ll certainly become better informed and possibly destroy a few misconceptions along the way. To produce torque and horsepower requires a mixture of air and fuel. To produce 1 hosepower for 1 hour requires approximately 0.5 lbs of gasoline. If you ran a single-cylinder engine, like the one in your lawnmower under load of 1 horspower for 1 hour and weighed the fuel tank before and after, the tank would weigh approximately 0.5-lb (five tenths of a pound) lighter. Therfore the equastion for fuel flow is 1H.P.= 0.5-lb of fuel, per hour. This expressed on the dyno sheet as B.S.F.C (Brake Specifique Fuel Consumption). Incidently the figure for alcohol is approx 1-lb of fuel, per h.p. per hour. Typically a 600-hp engine will require 300-lbs ofgasolene per hour and by the same formula an 800-hp engine needs 400-lbs. Remember these quantaties of fuel have to be delivered past the needle and seats and the fuel pressure regulator. Consider also the fuel delivery system has to combat “G”Force loadings tht can threaten to stall the fuel in the line(this may also give a clue as to why a fuel line that is to large can be as harmfull as one that is to small). When you have only one carby it should be easierto feed than two,right? Wrong, in an engine with a tunnel- ram layout, both the needle and seat area and the flout bowl capacity have doubled! Whereas the single four barrel has a much harder task in keeping the fuel bowls full A 700-hp tunnel-ram engine needs 350-lbs of fuel per hour which equates to a little over 85-lbs per float bowl A 700-hp running a single four-barrle will need 175-lbs per float bowl. If your fuel delivery system is weak? Your engine may not miss or burn up parts. It may just not perform to expectations.All the new hop-up parts that you have fitted may have overstressed an already taxed fuel system. When your car isn’t performing always carry out the GAS CAN TEST first its one of the least expensive diagnostic aids youll encounter. Use only a 1 gallon gas can.Insert all of your fuel lines from your regulator into the fuel can switch on your system and carfully measure the time it takes to fill it.In drag racing terms a 12sec car will need to pump 1-gall in 35-seconds,11sec car 30 seconds, 10sec. Car 25 seconds,9sec. Car 20seconds, 8sec. Car 15 seconds and under 12seconds for a 7second car. Partially reprinted with the permission of Barry Grant fuel systems.