How small is too small on the return line???
How small is too small on the return line??? Hi all. Im working up the details for my 77 vette LS1 conversion and had a question. Im using the 99 vette FPR and was wondering how small is too small for the return? I am using 6AN for everything else but would like to use a union reducer right at the tank so I can use my stock 1/4" return line going into the tank. Would that be too much of a restriction with a walbro 255 pump? Also on the FPR, are the inlet and return both 3/8"? Thanks for any help!
The Corvette FRP has 3/8 inlet, 5/16 return and 3/8 outlet forward to the rail. Most people, including Chevrolet, put the FPR back near the tank so only one line has to go forward. My return line is only about 12-15 inches liong.
Pat
Pat
I am actually mounting it in the back about 3 feet from the tank. I plan on running braided line between the FPR and tank. 5/16 to 1/4 isnt bad at all as far as a reduction goes. I was just worried that too small of a return would result in a pressure build up that would defeat the purpose of the regulator.
New question. How do I run a AN fitting on 5/16? They dont make a 5AN do they?
New question. How do I run a AN fitting on 5/16? They dont make a 5AN do they?
Originally Posted by hosspowerinc
I am actually mounting it in the back about 3 feet from the tank. I plan on running braided line between the FPR and tank. 5/16 to 1/4 isnt bad at all as far as a reduction goes. I was just worried that too small of a return would result in a pressure build up that would defeat the purpose of the regulator.
New question. How do I run a AN fitting on 5/16? They dont make a 5AN do they?
New question. How do I run a AN fitting on 5/16? They dont make a 5AN do they?
I agree...if you are running 3/8 feed and a 1/4 return...even at 3 feet I would say at idle...its going to build up back pressure. probably at good speed or accel, you wont see any issues...but you MIGHT see a backup of pressure at idle when MOST of the gas is being recirculated. So yes 5/16 would also be my best opinion.
Actually I will be running -6AN for the 3ft of return and put a reducer right at the tank. Even so, I will change it to 5/16 or 3/8 to be safe. How would I go about doing this I wonder? Could I cut out the existing 1/4" tube, drill the hole larger, and weld in a piece of 5/16 or 3/8? Do they make an o-ring fitting that I just drill a hole and use 2 nuts and a threaded shaft that would run through the tank. One nut on the inside and one on the out? Like a metal valve stem for lack of a better example.
77 Vette Fuel Return Have no idea what your tank fitting arrangement looks like, so I couldn't say. But I would do it the very best way possible, with the best parts, no matter what the cost of the parts are.
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Ive been working on it this morning. I ended up using the factory 3/8" feed as a return, removed the factory 1/4" return, and added another 3/8" tube for the new feed. It worked out well since I converted it to a in-tank pump and I have no worries about flow. I just have to weld the new tube in and its ready to go.
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That should work out well.. as there have been a few threads on people just doing what you are now or something like it.
I guess you could have gotten away with the 1/4" line, would not have been the best, but it would have worked. But it is better to make the effort now than later..!
I guess you could have gotten away with the 1/4" line, would not have been the best, but it would have worked. But it is better to make the effort now than later..!
