Fuel Lines - Sizes - Best Practices

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SierraM37
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Fuel Lines - Sizes - Best Practices

Post by SierraM37 »

Also posted on Power Wagon Advertiser forum-

OK - Almost done with running my brake lines for the 4wheel discs - Now it's time for the fuel lines.

It looks like there are two sizes that run into and out of the tank fittings. 3/16th's and what is the other size? One runs to the fuel pump and the other runs back from the carb correct?

I've seen all the comments (Thanks Charles) on adding an electric fuel pump. If you do this, do you bypass the mechanical fuel pump and cover it up? Does using an electric pump change the layout of the fule lines?

Thanks in advance. :D
Todd
'52 M37 W/W
'52 M37 WOW
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Re: Fuel Lines - Sizes - Best Practices

Post by MSeriesRebuild »

SierraM37 wrote:Also posted on Power Wagon Advertiser forum-

OK - Almost done with running my brake lines for the 4wheel discs - Now it's time for the fuel lines.

It looks like there are two sizes that run into and out of the tank fittings. 3/16th's and what is the other size? One runs to the fuel pump and the other runs back from the carb correct?

I've seen all the comments (Thanks Charles) on adding an electric fuel pump. If you do this, do you bypass the mechanical fuel pump and cover it up? Does using an electric pump change the layout of the fule lines?

Thanks in advance. :D
The fuel line leaving the tank is 5/16". The 3/16 line is only a vent, not an issue except for fording.

Best to remove the mechanical pump if electric is used, by all means bypass it if you do leave it in place, otherwise gas could spill into the oil pan. If using an electric pump, best to mount it as close as possible to the tank, they are designed to push fuel instead of pull it. No need for reconfiguring the lines unless you just wanted too. Just plumbing the pump in is all.
Charles Talbert
www.mseriesrebuild.com
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Post by Josh »

you want to make sure to use a pressure regulator with the electric pump, ideally with a return line back to the tank, or you'll have flooding issues when the pump overpowers the needle and seat in the carb.
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Post by MSeriesRebuild »

The electric pumps we have used are a 4PSI max delivery pressure. This is not enough to overwhelm the needle/seat assembly and performs flawlessly without a regulator. The needle and seat assembly is good up to 5.5 PSI according to specs. If you chose a pump that delivers more pressure, a regulator is absolutely a necessity. A return line is a great idea also.
Charles Talbert
www.mseriesrebuild.com
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