Another ? for Fuel Return Lines
Thread Starter
Racer
Joined: Mar 2006
Posts: 313
Likes: 0
From: Fairfield PA
Another ? for Fuel Return Lines
I didn't want to hi-jack the other tread regarding this so here is my question.
I have an 80 that I am currently replacing the stock 350 with a new turn key crate 350. The crate motor came with a fuel pump that has an inlet and outlet only. Is in ok to cap off the fuel return line and install a vented gas cap if necessary? I did a search and read conflicting issue regarding this.
I have an 80 that I am currently replacing the stock 350 with a new turn key crate 350. The crate motor came with a fuel pump that has an inlet and outlet only. Is in ok to cap off the fuel return line and install a vented gas cap if necessary? I did a search and read conflicting issue regarding this.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
I didn't want to hi-jack the other tread regarding this so here is my question.
I have an 80 that I am currently replacing the stock 350 with a new turn key crate 350. The crate motor came with a fuel pump that has an inlet and outlet only. Is in ok to cap off the fuel return line and install a vented gas cap if necessary? I did a search and read conflicting issue regarding this.
I have an 80 that I am currently replacing the stock 350 with a new turn key crate 350. The crate motor came with a fuel pump that has an inlet and outlet only. Is in ok to cap off the fuel return line and install a vented gas cap if necessary? I did a search and read conflicting issue regarding this.
I would think that if your fuel pump's pressure output doe snot exceed the limits of the carb then you don't need a return line. However, return lines are a good idea to have, and you can add one even if the pump does not have provisions for such.
Just aft of the pump, as the line goes up to the carb, add a 'T' to the fuel line. Run that 'T' back to the return line on the frame. Make sure it's of a small inside diameter than the fuel line. It'll bleed excess pressure off without starving the carb when it needs fuel. I think half diameter would be sufficient if adding a return junction.
Thread Starter
Racer
Joined: Mar 2006
Posts: 313
Likes: 0
From: Fairfield PA
I would think that if your fuel pump's pressure output doe snot exceed the limits of the carb then you don't need a return line. However, return lines are a good idea to have, and you can add one even if the pump does not have provisions for such.
Just aft of the pump, as the line goes up to the carb, add a 'T' to the fuel line. Run that 'T' back to the return line on the frame. Make sure it's of a small inside diameter than the fuel line. It'll bleed excess pressure off without starving the carb when it needs fuel. I think half diameter would be sufficient if adding a return junction.
Just aft of the pump, as the line goes up to the carb, add a 'T' to the fuel line. Run that 'T' back to the return line on the frame. Make sure it's of a small inside diameter than the fuel line. It'll bleed excess pressure off without starving the carb when it needs fuel. I think half diameter would be sufficient if adding a return junction.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
If you are buying a new pump, consider a race pump, which is a piston pump vs diaphragm. Much better and they won't wear down over time like the cheaper ones. They can be regulated to perfectly match the needs of your carb, and most have the return line provision.
