Is There Another Way to Install a Fuel Pump? (Gasoline/Petrol)

[Chotu]

I currently have a fuel system with 3 inboard gasoline/petrol tanks.

A fuel line runs uninterrupted from each tank into an on-deck “explosives box” which is over the water and vented with holes in the bottom to allow gasoline, propane to drain overboard in case of emergency. Super safe.

My fuel pump, Racor filter/separator and the valves to select the active fuel tank are all located in this deck box locker.

I’ve always had a fuel problem. Pumps aren’t lasting, fuel delivery can be spotty occasionally.

From what I’ve read, sucking fuel up from a distance is a bad idea and can cause vapor lock, which I think I run into occasionally. You’re supposed to push the fuel up the hill by having the pump near or inside the fuel tank. The gasoline system is supposed to be under pressure.

The proper installation of a gasoline fuel pump is at direct odds with my safety protocols.

How can I reconcile these issues?

Do I put a fuel pump AND my ball valves for switching tanks below?? Sounds risky.

Do I put 3 fuel pumps below? One for each tank? Then close off other tanks from above in the “explosives box” with ball valves and have a complicated system where I have to manage non-return valves and 3 different fuel pumps to push the fuel up?

Is there any way to suck gasoline/petrol up a 60” hill from tank to my on deck explosives box?

What’s normally done in gasoline inboard boats?

What meets ABYC safety guidelines?

I can’t seem to get this one right. I thought I could suck fuel up 60” and all would be well.

NOTE: I also put the fuel pump AFTER the Racor. So it goes fuel tank-> 60” lift -> ball valves gallery for selecting tank -> Racor -> Fuel pump -> outboard engines.

[Sailmonkey]

Normally on gasoline boats the fuel tank and engines/pumps occupy the same space.

How about using a fuel transfer pump to move the fuel to a 4th day tank on the bridge deck.

[rslifkin]

My gas inboards have mechanical pumps on the engines and an electric one on the generator. But they're not lifting fuel very far. Up through the dip tube, then through the lines. Pumps are below the tops of the tanks.

In your case, you might need a different pump setup. What are you using for a pump currently?

[Chotu]

Originally Posted by Sailmonkey

Normally on gasoline boats the fuel tank and engines/pumps occupy the same space.

How about using a fuel transfer pump to move the fuel to a 4th day tank on the bridge deck.

Silly question, but why can’t I use that same fuel transfer pump to feed the fuel system I already have? Can that pump lift the fuel up 60” by suction?

Forgive me. I’m out of my element here. My question might seem silly. M

I’m trying to avoid more fuel tanks if possible.

[Chotu]

Originally Posted by rslifkin

My gas inboards have mechanical pumps on the engines and an electric one on the generator. But they're not lifting fuel very far. Up through the dip tube, then through the lines. Pumps are below the tops of the tanks.

In your case, you might need a different pump setup. What are you using for a pump currently?

From the top of the tanks (they are tall ones), I’m lifting about 12-16 inches. They have a long dip tube pickup inside the tanks.

For pumps, I’ve been using these ones.



However, I just bought a marine fuel pump from a local marine store that looks like this. Much bigger.




My flow rates max out at 6 gallons per hour WOT. So flow rate isn’t an issue I don’t think. It’s hard to find fuel pumps with low pressure and fuel flow rates actually.

I’m happy to throw any money at the pump if it can pull the fuel up to my “explosives box.” I just don’t know which one can.

[Chotu]

I don’t think my last pic is a fair representation of the marine pump. I’ll have to take a picture of it out at the boat.

[Sailmonkey]

Originally Posted by Chotu

Silly question, but why can’t I use that same fuel transfer pump to feed the fuel system I already have? Can that pump lift the fuel up 60” by suction?



Forgive me. I’m out of my element here. My question might seem silly. M



I’m trying to avoid more fuel tanks if possible.

Because the transfer pump runs only long enough to move fuel from the main tank to the day tank. Therefore it develops less heat and is given an opportunity to cool down. Also a typical transfer pump is way too large to supply an engine.

[thinwater]

The initial boiling point of many e-10 blends is 95-100F, so you are not going to reliably suck them upwards AT ALL on a hot day. Not happening, it will bubble in the line or pump. The pump specs don't matter. It may work sometimes, but not all the time.


On the PDQ in the image, the gas tank in on the bridge deck, above the engines. The tank compartment has drains overboard, as do the fuel line runs. Even safer.


The simple solution is an in-tank pump (no seal leaks) that only runs when the motor is keyed on. Very common. You just need to maintain the system. Having the filters in a box is good, since they are the most leak-prone component.



(I do refinery engineering)

[rslifkin]

The day tank in the explosives locker isn't a bad idea. Otherwise, it's a matter of finding a pump meant for a small-ish carb-ed engine (low pressure) that won't push too much volume for the outboards. A too-big pump may run hotter, as it's working against more outlet restriction (and likely bypassing through an internal pressure relief).

If you could find something low pressure enough, you could always try an automotive style setup with in-tank pumps. Although that means more of the fuel system is pressurized, so I'd avoid it if possible.


I remember you mentioning 3 tanks on your setup. Is that 2 in 1 hull, 1 in the other? Or 1 per hull and one somewhere else?

[Scubaseas]

Look into https://www.facet-purolator.com/dura-lift/
These are used for refer trucks to lift the fuel from the tank to the box mounted compressor.

[Scubaseas]

https://www.facet-purolator.com/dura-lift/

Just dawned on me that the OP may have me blocked for being clueless (oh the shame) so someone may wish to pass this link/post on.

Cube pumps do not pull well. Push, yes. They also can over heat and can cause vapor lock in hard usage like trying to pull fuel uphill. The cylinder type pumps tend to work better for continuous use but they also are pusher pumps, not pullers. The cylinder ones are usually a lot quieter too.

There are high lift pumps as linked above that are used in refer truck and trailers that are designed to pull fuel from the tractor/cab and pump it up to the top of the box. They can lift to 10', are gasoline rated and are salt spray resistant.

[Sailmonkey]

Originally Posted by Scubaseas

Just dawned on me that the OP may have me blocked for being clueless (oh the shame) so someone may wish to pass this link/post on.

Cube pumps do not pull well. Push, yes. They also can over heat and can cause vapor lock in hard usage like trying to pull fuel uphill. The cylinder type pumps tend to work better for continuous use but they also are pusher pumps, not pullers. The cylinder ones are usually a lot quieter too.

There are high lift pumps as linked above that are used in refer truck and trailers that are designed to pull fuel from the tractor/cab and pump it up to the top of the box. They can lift to 10', are gasoline rated and are salt spray resistant.

Of course the problem with pulling gasoline in a tropical environment is the reduction in pressure. As we all know a reduction in pressure also causes a reduction in boiling point. As the gasoline boiling point is already quite near normal daytime tropical temperatures, lifting with suction makes this problem worse. The only real solution is to push the gasoline uphill.

[Scubaseas]

Originally Posted by Sailmonkey

Of course the problem with pulling gasoline in a tropical environment is the reduction in pressure. As we all know a reduction in pressure also causes a reduction in boiling point. As the gasoline boiling point is already quite near normal daytime tropical temperatures, lifting with suction makes this problem worse. The only real solution is to push the gasoline uphill.

If directed at me you are preaching to the choir. I couldn't agree more that one should push the fuel, and the pump goes before the Racor as opposed to trying to pull vacuum through the Racor (which it's not designed for). In tank pumps also benefit from using the fuel as coolant.

OP wants an option of a gasoline pump that is designed to lift over 60" which I linked. I have no other opinion or motive than that.

[oleman]

The FACET company has a compete line of electric fuel pumps . They have models for everything from small carb engines to large diesels. Lots of how-to's are available at Pagasus Racing Supplies, in New Berlin WI. Their tech support and pricing are very good. They had the exact fuel pump for a Honda EV4010 genset that I restored. NO, I do not use the Honda EV4010 in the vessel.

[Squanderbucks]

It seems to me the issue is how far the tanks are from your Racor and the depth of the tanks. As I see it you only need one fuel pump after the Racor and before a fuel selector valve (manifold). It doesn’t matter if your pump is near the engine or near the Racor. What does matter though is if you have to run a considerable length of hose - you need to up size the ID hose size. Don’t know what you have now but trying to run fuel through 1/4” or 5/16” can be quite restrictive. I would suspect 3/8” would be necessary to reduce the load on the pump.
A simple manifold out of brass pipe and ball valves would suffice.