Topic: Fuel pump and fuel lines
in Forum: C3 Fuel, Emission Control, and Exhaust Systems
Already a Member?
Click Here to Login
Not yet a Member?
Click Here to Register for Free!
The new fuel pump on my engine only has a provision for one fuel line. There is no hookup for the return line. The engine builder said to plug up the return line, as the new engine doesn't need it. Is this ok to do? What is the purpose of the return fuel line (is it more to do with air flow or fuel)? Thanks in advance for the help 
!
!SPONSOR AD:: (Our Sponsors help support C3VR)
Lifetime MemberModerator
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
The return line serves more than one function. First, of course, is to return to the tank any un-needed fuel while still keeping the fuel pressure correct. A second benefit is to keep the fuel in the lines from getting hot, and possibly vapor-locking.
You can run with no return line...it was done that way for years. I would recommend taking a fuel pressure reading once you have everything up & running, to make sure you're not gonna have a too high pressure. If it looks like the pressure is within reason, then you're good to go. If it appears to be high, you may want to consider some sort of pressure regulator.
You can run with no return line...it was done that way for years. I would recommend taking a fuel pressure reading once you have everything up & running, to make sure you're not gonna have a too high pressure. If it looks like the pressure is within reason, then you're good to go. If it appears to be high, you may want to consider some sort of pressure regulator.
Joel Adams
C3VR Lifetime Member #56 
My Link 
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
Ok, that makes sense Joel. Here's my dumb question for the day. Does anyone have a source for a mechanical fuel pump that has a provision for the return line? I've only been able to find pumps with two ports.
Lifetime MemberModerator
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
Lifetime MemberModerator
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
Be sure, if you call Paragon, or Riks about these pumps to ax if they do in fact have return line provisions. The pic on the one from Riks does, but the one from Paragon doesn't seem to have one. The pics may not be of the actual pump tho...could just be a "generic" pic for all of the pumps offered.
Joel Adams
C3VR Lifetime Member #56
My Link
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
I called Paragon. They weren't sure, so they pulled the pump, opened the box and verified it does have it. Great customer service. I'll order from them again
.
.If you live in hot climate or in the mountains make sure to use the pump with the return line. This greatly reduce vapor lock.
If ever comes in effect a mixture of alcohol and gasoline is a must.
Carlosvette1970
I'm in a really hot climate John and have the same setup with the return line blocked and have had no problems. However, I do plan on replacing the mechanical pump with a Holley electric and regulator once funds allow me too. this will let me fine tune my fuel supply to my Holley carb.
in Forum: C3 Fuel, Emission Control, and Exhaust Systems
SPONSOR AD: (Our Sponsors help support C3VR)