Can a fuel return line be too big?
You can’t get in trouble with too big of a return line, just your wallet, -8 is fine, -6 can be used on smaller pumps with no problem. EFI can handle a higher base/back pressure, no big deal to have 30 psi of back pressure in the return on efi.
What size should my fuel return line be?
Fuel Return Line Size and Installation The Fuel Return Line should be at least the same size, or one size larger than the supply. Make sure there are no sharp bends or kinks. The return line should direct fuel close to the bottom of the tank and away from the pickup.
Does a fuel injection return line have pressure?
In return-type systems, fuel is returned at a lower pressure than that found in the feed line or fuel rail. These can be replaced and upgraded as required. These regulators work by allowing the line pressure to build to a level higher than normal line pressure before venting excess pressure back to the tank.
How does a fuel return line work?
How do fuel return lines work? In fuel systems with a return line, the fuel pump is continuously pumping gas through the fuel system at a much higher rate than is actually needed. This keeps gasoline in the fuel lines cool and flushes out any vapor bubbles that might form. This prevents vapor lock in your fuel system.
Why does EFI need a return line?
With Holley’s new returnless OEM-style fuel tank modules, the need to install a return line back to the fuel tank is eliminated. By incorporating a fuel pressure regulator into the module, the fuel is returned before it ever leaves the tank, which greatly simplifies installation.
How does a bypass fuel regulator work?
With a bypass style regulator, fuel enters through the inlet port (A) and travels past a fuel bypass valve/fuel return line port (which governs fuel flow and pressure) (B) and then is distributed through an outlet port to the carburetor or EFI fuel rail (C).
What is fuel tank vent?
Each tank is vented (or pressurised) to allow air into the tank to take the place of burned fuel; otherwise, the tank would be in negative pressure which would result in engine fuel starvation. A vent also allows for changes in atmospheric pressure and temperature.
Where is the fuel tank vent?
the tank is vented into the filler neck(where you put fuel in) and that is sealed by the gas cap. So yes you need a vented cap. All modern gas caps are vented is some form. Look at the bottom that faces the gas and you can see the valve inside.
Should outboard gas tank vent open or closed?
All outboard motors have vented gas tanks. Open the vent after you connect the fuel hose and tank to your motor. If you do not open the vent, your motor will experience a vacuum lock. Remove the filler cap from the fuel tank if your motor begins to “gasp” while you are making way in your boat.