Pros and Cons changing setup to one Fuel Line

chadpcb

Petty Officer 2nd Class
Joined
Jul 24, 2010
Messages
119
I am debating on changing my current fuel setup. Would like opinions on pros and cons of doing so.
What I know is that my starboard tank draws more fuel than my port tank.
I do know with current setup there are more connections than there would be with proposed setup.

We are dealing with a IB Merc 5.7 4BBL
Fuel line runs are about 12 foot on current setup
I have attached a picture to show you how it is setup and how I would like it to be setup.

PROS and CONS would be great...

Thanks

Chad
 

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Bt Doctur

Supreme Mariner
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Aug 29, 2004
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19,344
with a single engine the fuel draw is the same .It uses the same amount of fuel (gallons) from either tank. changing the fuel line confiruration does nothing to reduce fuel draw or usage.I would remove one of the filters , don't need both of them.
 

Bondo

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Apr 17, 2002
Messages
71,082
I am debating on changing my current fuel setup. Would like opinions on pros and cons of doing so.
What I know is that my starboard tank draws more fuel than my port tank.
I do know with current setup there are more connections than there would be with proposed setup.

We are dealing with a IB Merc 5.7 4BBL
Fuel line runs are about 12 foot on current setup
I have attached a picture to show you how it is setup and how I would like it to be setup.

PROS and CONS would be great...

Thanks

Chad

Ayuh,.... Yer not leavin' Both fuel valves open at the same time are ya,..??

If so, That's yer Problem,.....

Ya gotta run 1 valve open at a time,.... Never both,....

Did you post this question at OSO,..?? I just answered the same question over there,....
 

chadpcb

Petty Officer 2nd Class
Joined
Jul 24, 2010
Messages
119
BT - I am not concerned or trying to change fuel draw. I am concerned about the multiple connectins and the double run of fuel line from the stern of the boat to the engine.

Bondo - Question #1 - Yes I leave both fuel valves open. Each tank has its own Fuel guage. I do this to keep the boat balanced. When your talking 400lbs or fuel in each tank it is not wise to run one then the other.

Question #2 - No this is the only place I have posted this question.

Question Bondo. Why only run one tank at a time?
 

chadpcb

Petty Officer 2nd Class
Joined
Jul 24, 2010
Messages
119
Bondo I forgot to mention that both tank lines run into the WS one on each input with only one output to the filter mounted on the engine.

BT there are actually 3 filters in this system. Main WS then to Engine Mounted Filter then onto the carb filter.
 

Bondo

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Bondo - Question #1 - Yes I leave both fuel valves open. Each tank has its own Fuel guage. I do this to keep the boat balanced. When your talking 400lbs or fuel in each tank it is not wise to run one then the other.

Ayuh,.... Without a selector valve, You have No control over which tank is drawn down,.....

Without selector valves, it can, 'n probably will, draw one tank empty, 'n then yer done, goin' nowhere,.....

There are manual, 'n electric selector valves,...

No reason ya can't re-plumb it like ya want, so long as you have the ability to switch tanks, whether electrically, or manually,...
 

achris

More fish than mountain goat
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May 19, 2004
Messages
27,468
Nice trick question... Those 2 setups are the same. They both have a line from each tank going through a valve, to the first filter, then a single line to the engine. The only thing different is the location of the first filter. But as for the actual fuel flow, nothing changed.

Personally, as long as the engine mounted filter is man enough for the job, delete the first filter and just have the 2 valves. As already said, if you run with both valves open, then the pump will draw from the tank with the least resistance.It's one OR the other. I can't ever see a situation where both valves would be open...

Sorry, just thought of one. If you have a transfer pump you would need both valves open the transfer fuel from one tank to the other...

Chris.....

EDIT: with a run that long, I would use LARGE lines, 3/8" as an absolute minimum, 7/16" or 1/2" would be better. If you do stay with 3/8", then put a vacuum gauge on the front of the pump to make sure you're not pulling too hard. (no more than 2" of vacuum)...
 
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thumpar

Admiral
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Jun 21, 2007
Messages
6,138
Both setups end up doing the same thing in the end. The only difference is where things are located.
 

chadpcb

Petty Officer 2nd Class
Joined
Jul 24, 2010
Messages
119
Hey everyone thank you for your input. I have decided to stay with the current setup. I thought to no end on this and the main reason why I am not changing it is....

As it is setup now I have 2 lines leading to the main WS. If one line was damaged for some reason then I can shut that line off and run on the other tank. If I only had one line running to the engine and that line got damaged some how then I would have to be carrying some to splice fuel lines together at all times....

I do appreciate all of yalls input....
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
... then I can shut that line off and run on the other tank.....

I hope you mean 'switch to the other line'... You should not be running with both valves open... You will drain one tank, then suck nothing but air. If you want to use the same amount of fuel from both tanks, you need to add a 'trip tank', use a pump from each main tank and transfer the same quantity of fuel from each main tank to the trip tank and run on that... the other option is to change the valves every half hour or so... But, repeat, do not run with both valves open.

BTW, what I said about line sizes also applies to your current setup...

Chris......
 

chadpcb

Petty Officer 2nd Class
Joined
Jul 24, 2010
Messages
119
Chris the line size I am currently running is 1/2". As far a trip tank goes unfortunately I do not have enough room below deck to put one in but I do like the idea of that.
 
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