Reply to "Vapor Lock"

...Which side of the Fuel Pump is the Filter mounted in the fuel hose? It should be in-line on the 'Pressurised Side' between the pump and the carburator. IF it is on the Vacumn side (between fuel tank and the pump), when HOT the fuel May 'Boil' inside of the filter, especially if it is of the 'tin can' type. When this happens your fuel pump will be 'trying' to pump Vapor; hense the term 'Vapor Lock'. If this is not your case; you may have a clogged filter in the carb inlet (Holley). OR/AND the fuel lines around the pump may be getting over-heated from being to close to the header primaries, a thermal covering may help here. While we are on the subject of 'fuel starvation'! Here is a word of warning about something not many people realize; I am speaking of the HOLLEY fuel pressure REGULATER (that 'neat' little Blue painted aluminum thing, that is adjustable). If you have ever taken one apart, as I have; you can't help but notice that ALL the fuel that passes through this device MUST go through an Orifice with a Very small Diameter of aprox. .150" (I'am guesstimating here because I did not actually measure the 'Ball Seat',but it is that tiny. My point is that at top end high revs, fuel starvation would be expected! And when I use to run dual quads (on another vehicle) I, at least, used one regulater for each carburetor. BUT that is still, ONE small Orifice to 'Feed' 2 FloatBowls. Good-Luck with it!