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Electric Fuel Pump placement suggestions

swc65

Regular Contributor
I am replacing an existing non-marine electric fuel pump on a SBC which was not machined for mechanical pump. The current pump is mounted to a metal cylinder on the front of the engine. I just bought a Carter P4594 Marine pump replacement. I know it must be down stream of the water fuel separator as is the current one and it must be within 12 " of the engine and as low as possible.

I'm thinking of some method to mount to the boat "floor" next to the engine but not sure how to make it stable. I've attached a pic with some identification. I've place red arrows to obvious locations however they will not meet 12 inch rule.

I have rear bench seat removed which normally sits right in front of the engine.



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The bracket that will be included with the Carter style electric fuel pump should mount to the cylinder block in the same location as would a mechanical fuel pump.

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New_Silver1_SITE.jpg



By the way, gasoline vapors are heavier than air.
Your Turbo or In-Line style blower motor's suction hose should reach down into the deeper area of the engine bay.
As it is now, it is incorrect!

Also, the
Turbo or In-Line style blower motors will not hold up to continuous duty.








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I'll double check the block but I don't think it has the holes machined for a mechanical pump. Hope I'm wrong. Its not stock engine that came with boat.

I have the suction hose disconnected currently while working on engine. Will address.
 
Also, I would suggest getting rid of those standard fuel line clamps, and go with the Euro style.

The Euro style has a nice smooth interior.
(the standard US style has cuts in the band that will pull and tug on the fuel line exterior while tightening them)


 
Another follow up. I double checked the mounting boss on the engine block. Should have taken a pic but didn't. Where a mechanical fuel pump would be mounted on the front, starboard side of the block' there was a mounting boss with one threaded bolt hold machined. Instead, I screwed down pressure treated wood to the floor of the engine compartment near the proximity of the location where the fuel line emerged from the tank and within 12" of the engine. Was able to mount easily there with only a small amount of additional hose required. I installed a Carter marine fuel pump, safety switch, and relay. I should be more safe now.

Also reworked multiple terminations I had created before, using non-insulated connectors (and proper crimp tool) and heat shrink. Hopefully eliminated a few sources of failure; however I know that a 28 year old boat will always need attention.
 
Back to the drawing board. Installed the fuel pump ran great for 6 weeks then it quit on me this week while tubing. I applied 12 volts directly to the pump but it is dead. I don't know if it just failed or burned up however I'm guessing the latter. Not sure if its correct but after I removed the pump, I put my Fluke meter in series with the wiring and only measured 10.75 Volts. I know I should have 12 volts going to it from the relay I installed. Would low voltage cause the pump to burn out?

I checked the relay and heard it clicking on. What would prevent it from delivering 12 Volts to the pump? Was I accurately measuring the voltage in the manner in which I tested it, by simply placing the meter in series with the positive and ground wires?

Not sure if its related but I found my ignition relay was cracked on the battery side, pic included. This may have explained why the engine turned over slowly when hot and after running. I can see how this would have impacted the fuel pump, however the ignition wire to the fuel pump relay Terminal 86) was terminated on the "I" Terminal of the Ignition relay.

I have a new Ignition relay and fuel pump on order but I'd like to positively identify the cause of the fuel pump failure.

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