Return line size

[Johnymd]

I'm in the midle of a 1JZ conversion into my 240Z and at the moment I'm looking at the fuel delivery system. I'm planning on using the old fuel tank feading a fascet red top, filter, then surge tank. Surge tank then returns to fuel tank. For the HP side I'm going from the bottom of the surge tank into a bosch 044 then straight to the engine. The return from the engine then goes back into the top of the surge tank.

 

So, my question is what size return do I need so as not to build up too much pressure on idle at the fuel rail? I think the pressure is regulated by opening the return (please correct me if I'mm wrong). I fitted new copper line a couple of years ago but they are the same size as the originals.

 

Any advice welcome.

[Noddle]

I'm in the midle of a 1JZ conversion into my 240Z and at the moment I'm looking at the fuel delivery system. I'm planning on using the old fuel tank feading a fascet red top, filter, then surge tank. Surge tank then returns to fuel tank. For the HP side I'm going from the bottom of the surge tank into a bosch 044 then straight to the engine. The return from the engine then goes back into the top of the surge tank.

 

So, my question is what size return do I need so as not to build up too much pressure on idle at the fuel rail? I think the pressure is regulated by opening the return (please correct me if I'mm wrong). I fitted new copper line a couple of years ago but they are the same size as the originals.

 

Any advice welcome.

 

The fuel regulator regulate the pressure, as long as the pump can supply it, and the return large enough as not to be overwhelmed. (I don't know what minimum size is needed)

 

I have a question about the use of copper pipe, will this cause a issue years down the track with it going hard (flexing over a long period), and cracking ?

 

Nigel

[ktm]

The fuel regulator regulate the pressure, as long as the pump can supply it, and the return large enough as not to be overwhelmed. (I don't know what minimum size is needed)

 

Make it the same size as the feed line and you will not have any issues. Yes, it can be smaller, but it is just easier to make both lines the same size.