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I need to replace my mechanical fuel pump on my carburated 351w and I was thinking of switching to an electric pump.
I would also!
Is there any difference between an auto pump and a marine electric pump?
Yes!
You can safely install a Marine approved carburetor style (i.e., 4 to 7 psi max) electric fuel pump.
The N/O LOP (Normally Open .... Low Oil Pressure) switch is a requirement.
I would use a relay that is triggered by the LOP S.
Reason: If Engine oil pressure was to drop below the N/O LOP Switch "closed" pressure, the relay would interrupt fuel pump power.
The mechanical fuel pump stops pumping fuel when/if the Egine was to stall........... whereas (in the absence of a N/O LOP Swtich) the electric fuel pump would (key word "would") continue to pump fuel when/if the Engine was to stall!
The "start-by-pass" is not a requirement, but is necessary!
A "momentary" helm switch (in lieu of the "Start-by-pass" circuit) gives us the option of priming the carburetor fuel bowl prior to Engine cranking!!!!
This aspect alone makes the installation well worth doing!!!!
NOTE: this must be a "momentary" switch as to NOT violate USCG rules!
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