CLASS RACER FORUM - fuel line

This sounds crazy, but running a big huge line from the pump at the rear of the car to the regulator at the front can aggravate a fuel starvation problem.You can sit there with the pump on adjusting the regulated fuel pressure all you want, and to no avail, because the weight of the fuel in the large line reacts to inertia forces within itself, resisting forward motion inside the line ahead of the pump. A smaller main fuel line doesn't do this,because inertia forces on the fuel are much less. Sometimes,more isn't better. Number 6 AN fuel line is about 3/8" inch ID, the #8 should do it, but that's where the placement of the regulator in front of or to the rear of the carb might come into play here, as well.Pro stock cars leave so hard that it takes a huge push to overcome the weight of the fuel trying to stand still in the line.High pressure overcomes the inertia on acceleration, but floods the engine by overcoming the needles and seats when the car isn't accelerating.Critical balance here between fuel flow requirements of the engine,fuel line diameter,pump volumne,and pump pressure.