Fuel Line Diameter
Posted: Mon Apr 22, 2013 6:16 am
Hi, new guy here with a question concerning fuel line adequacy.
I have a '59 Triumph TR3 with SU carbs that I'm considering changing to EFI. One consideration I have is the fuel lines. I see that it is usually recommended that 3/8" lines be installed, with a 5/16" return. The original feed for the mechanical pump is 5/16" diameter and comes out from the bottom center of the fuel tank, runs along the frame and up into the engine compartment. I like to splice into this line with the electric fuel pump, and run the return along the other side of the frame and dump back into the top of the tank where there is a vent line which is also 5/16" in diameter.
The stock engine is about 100 HP at 2.0 liters. My engine has been modified to 2.2 liters, and has, if I'm lucky, 130 HP. So, will a 5/16" fuel line support this?? Or is there another reason for using a 3/8" line other then the amount of fuel delivery necessary for the amount of horsepower being produced??
Also, If I have to go to a larger line, I'd also have to change the outlet fitting in the bottom of the tank. That would mean tank removal and welding in a different bung. Something I'd rather not have to do.
Thanks,
Art
I have a '59 Triumph TR3 with SU carbs that I'm considering changing to EFI. One consideration I have is the fuel lines. I see that it is usually recommended that 3/8" lines be installed, with a 5/16" return. The original feed for the mechanical pump is 5/16" diameter and comes out from the bottom center of the fuel tank, runs along the frame and up into the engine compartment. I like to splice into this line with the electric fuel pump, and run the return along the other side of the frame and dump back into the top of the tank where there is a vent line which is also 5/16" in diameter.
The stock engine is about 100 HP at 2.0 liters. My engine has been modified to 2.2 liters, and has, if I'm lucky, 130 HP. So, will a 5/16" fuel line support this?? Or is there another reason for using a 3/8" line other then the amount of fuel delivery necessary for the amount of horsepower being produced??
Also, If I have to go to a larger line, I'd also have to change the outlet fitting in the bottom of the tank. That would mean tank removal and welding in a different bung. Something I'd rather not have to do.
Thanks,
Art