Author Topic: Fuel return line  (Read 974 times)

Offline Cheyenne1010

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Fuel return line
« on: April 25, 2022, 07:12:55 PM »
I own a 1973 Chevy cheyenne C10 long bed 350engine with th350.i want to add a fuel return line to help with vapor lock and to keep the mechanical fuel pump from boiling the fuel.my truck came with a 2 line sending unit,1 line to the carburetor and the other line to a charcoal canister.my mechanical fuel pump is also 2 lines,1line to carburetor and the other line to the fuel tank.
          Can i change my sending unit and mechanical fuel pump to a 3 line fuel system?
     I know there are kits out there that can create that return line i want but i dont want to drill into my fuel tankany help with my issue will be very much appreciated.

Offline Rapid Roy

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  • Euless, Texas
Re: Fuel return line
« Reply #1 on: April 25, 2022, 09:37:25 PM »
If you have a metal line from pump to carb, you can get pipe insulation at Lowes or Home Depot and wrap around it. I did this from engine to pump. It is the round foam like material. So far in the last 7 years I haven't had vapor lock.

Sample of what I used. There are different ID sizes. Some has tape on both sides of split to stick together.
You can also use zip ties if the tape does not hold. I prefer to use the black ties over the white.

https://www.lowes.com/pd/Frost-King-1-2-in-Wall-Thickness-x-1-2-in-Id-x-6-ft-Foam-Pipe-Insulation/1001277248
« Last Edit: April 25, 2022, 09:39:25 PM by Rapid Roy »
1974 Cheyenne 10 LWB STOCK 350 W HEI /TH350/AC/4 BBL Quadrajet
Mopar by Birth
Chevy by Choice

Offline VileZambonie

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Re: Fuel return line
« Reply #2 on: April 26, 2022, 06:12:19 PM »
Adding a return will not solve that issue. The reason you would have vapor lock would be fuel lines improperly run too close to a heat source or a pressure drop/restriction in the feed line. A pressure drop will lower the boiling point of the fuel and could cause a vapor lock condition but if you are running the mechanical fuel pump with no kinks or restrictions in any of the hoses, your issue is you most likely do not have a vented gas cap.
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