Diesel fuel pump addition

[RAD]

I'm adding an electric diesel fuel pump for my Westerbeke 30 for priming and to overide the manual pump in case of malfuction, my question is do I pipe it inline with the manual pump between the seperator and the manual pump or after and b/4 the engine fuel filter or do I pipe it around the manual pump with tee's and shut off valves to isolate each pump.*o

 

[Tantallon]

fuel pump clarification

Hi Bob, do you mean mechanical ( engine driven ) pump instead of manual pump? If that's the case why not simply eliminate the mechanical pump and mount the electric pump on a bulkhead near but atleast even with or above the top of the tank. This would then lead to a coarse fuel filter and then to a fine filter before connecting to the engine. You can remove the mechanical pump and cover the hole in the engine with a plate and gasket you fabricate.

 

[Fred Ficarra]

Bob, I'd run 'em both.

That from a guy who has had many electric fuel pumps die on cars and even boats but never a mechanical pump. Sure, mechanical pumps don't do a lot of 'things' except get you home.

 

[RAD]

Fred,I agree with you but?

Are they both operating at the same time,piped inline with each other (will fuel pass thru the electric pump if its not on?)or should I pipe it so the electric pump is parallel with the engine pump?

 

[RichH]

Elec. Pump Location ......

IF you have flared connections (not simple ferruled compression fittings - the 'usual' type found on boats) put the electric pump between the fuel tank and the first filter. Will be vastly easier to purge air sequentiallly from the filters AND the injectors. Will also promote better filtration efficiency (life).Flared fittings wont 'relax' and vibrate loose like compression fittings, so you can totally depend on the electric pump NOT to have oil leak from the bad fittings .... and deliver the fuel oil into the bilge if there is a leak. Pressurized fuel lines will greatly aid the fuel filter service life ... deposition of debris will be ON the upstream surface of the filter media rather than INSIDE the filter media as occurs with vacuum mode (typically found on boats) of filtration.

 

[Fred Ficarra]

Bob, If I were using an electric pump to feed the

engine, my ideal pump would allow fuel to be sucked through it by the mechanical pump. I know of no way to find such an electric pump without physically testing it. I guess you have to suck on it. Look for vane pumps. Most should 'suck' well. The one on my web site seen in the upper right of this photo is automotive. But with diesel, who cares? I use this pump for transferring from the stern tank to the stock factory tank. ($60.00 or so, from Summit Racing) For what you want to do, I just use a squeeze bulb.

 

[RichH]

Poppit Valves ----

Most Electric fuel pumps have poppit check valves = meaning virtually NO pressure drop when the pump sits idle and the fuel is drawn by another pump somewhere else in the system. NAPA, AutoZone, etc. all supply these pumps .... just be sure that the rubber diaphragm is made from EPDM ... (EthylenePropyleneDiamineMonomer) - "compatible with Diesel oil". All the 'old standard' polymers will soften in long term contact with diesel oil as most of these pumps are for Gasoline.

 

[Fred Ficarra]

Rich, good info

So these pumps are the solenoid plunger style? or does a motor rotate a offset arm/crank, like some water pumps? The one in my picture is a vane pump.

 

[RAD]

Walbro diesel fuel pump

is the pump I'm going to add (see photo)I have not had a chance to check it to see if I can either blow or suck thru it.Thanks for the input.

 

[Fred Ficarra]

And with that vendor, how can you go wrong?