Can stock C4 engines vapor lock?

Discuss.

I would be shocked.

Lemme explain vapour lock and it will explain why modern return systems are not prone to it.

Vapour lock is when the fuel in the line boils to a vapour and no liquid gets into the fuel bowl. This is caused by the fact that the fuel pump is only bringing fuel up at about 15 PSI.

Modern fuel injection uses electric pumps. The fuel is driven to the lines at about 100 psi, and then fed back to the tank after passing through the rails. The pressure is lowered by the FPR to about 40 PSI, but the fuel goes into and fills the rail. The fuel is then dispensed, but much like a seeper hose, not all of it goes out. But unlike a seeper hose, the fuel loops back into the tank.

The return then drops the fuel, under pressure, back into the tank. The end result, the fuel never sits in the line long enough to boil off.

It also acts as a coolant. Did you know that the fuel can reach 120* on a hot day? Between ambient heat and engine heat coming back, it gets hot.

So to answer your question, no. There is little to no chance that you would be experiencing vapour lock.

Thanks, Andy! Just wondering...

Now... What is Lauren doing to make you ask this question in the first place?