Vapor Lock & Metal gas lines

[Anonymous]

I was looking back at some old posts that talked about switching to a rubber fuel line between the carb and fuel pump in cars that may be prone to vapor lock. I did make this small mod today and was just wondering if someone could tell me why : this is supposed to make a difference, I mean exactly what happens in a vapor lock and why does this help? The only thing I can figure is that the rubber line will expand slightly if gas boils and vapor is present. Am I even close??????

 

[66Sprinter]

As I understand it for normally aspirated engines...gas should stay as a liquid until it enters the carb where it is jetted (atomized) just before it enters the intake manifold and finds its way to each cylinder. Some carbs have small reservoirs to keep the supply going for a short time.

If the gas turns to vapor before it reaches the carb, it is less likely to turn back into a liquid and therefore interrrupts the feeding. Its sorta like suckin air in a straw when you are down to the last bit of soda in your glass. You get some air and some soda. If you carb gets some air and some gas then when it jets the full amount of fuel is not delivered. And the engine will cough, stall or rough idle.

Since the metal gas lines of the sixes are routed near the head the heat transfer can sometimes affect the gas in the line. Switching to rubber hoses or even a heat shield helps keep the gas in liquid form longer. As a kid, I remember getting Mom's (ALL STEEL) coffee can..making a few coils inside and then connecting to the fuel line and installing it in the front side of the engine. On cruise nights we'd stop off and fill the can with ICE to keep the fuel cold and get that little extra performance.

OK guys...this is an electrician explaining it...did I get it right!