Dual Fuel Tanks - Single Engine

spargs · Posted: Thu May 03, 2012 9:49 am Post subject: Dual Fuel Tanks - Single Engine

G'day guys,

I was hoping to get some advice on setting up dual fuel tanks but with a single diesel engine. The Savage is going to have twin 200 litre port and starboard tanks installed in it running to a mid mounted diesel.

Obviously being located against the gunwales, i would like to feed the engine simultaneously to ensure the balance of the boat is not overly compromised.

Is it as simple as running both tank supplies into a y valve which combines the two feeds into the engine? the fuel tank pickups will be located on the top panel of the tank so no gravity feeding will exist.

also since its a diesel there will be a return line required. Can i do a similar thing where the return lines are combined using a y fitting and then returned back to the individual engines.

looking forward to some feedback on this.

Cheers.

Noelm1 · Posted: Thu May 03, 2012 12:39 pm Post subject:

probably the best setup is a simple line between the two tanks, that way they are always equalised, you can also then have a filler on each side to make life easy too, that is the way it would normally be setup, the pickup can be from either tank, the connecting line/pipe is towards the bottom of both tanks

JayyyyGee · Posted: Thu May 03, 2012 2:44 pm Post subject:

You're asking a hard Q
Not sure how you can regulate an even flow from both tanks simultaneously talking boat here they dont stay level so relying on gravity feed to equally disperse fuel prob not an option
Having a Y piece not my choice i'd rather have both feeds going into the filter this @ least gives you the option to isolate a tank if ever reqired by using ball valves leading into filter
_________________
**************************
Save The Fish, Eat a Pussy Cat

glastronomic · Posted: Thu May 03, 2012 5:47 pm Post subject:

Is this a Bluefin and if so what diesel engine are you installing please?
Any pictures?
The balance factor of the separate fuel tanks is not realy a problem as diesel is roughly the same weight as petrol.
If you want to do this than the best way is to pump it in a collector tank and then into the engine.
The separate tanks with my petrol engine do not empty simultaneously but hap hazardously.
I run one at the time.
The 40 odd liter water tank on the lhs if fitted makes also not a real difference

fishingaz · Posted: Sun May 06, 2012 3:02 pm Post subject:

im with noelm on this one.just as we do on trucks.run a balance line between the tanks with a ball valve.run motor off the starboard tank and the return line back to that tank.i say the starboard side as im guessing this is a smaller size savage because of weight dist problems?
and 400ltrs in a smaller savage will take you a very long way.
advantage of balance line is you wont allways need all that weight .you can isolate the port tank and have seperate fuel from differant servos.
just make sure of a quality valve and line.and make sure you get proper diesel filler caps with seals .
good luck gaz.

when you get the work done put a sight tube on your running tank .easy to do. and you will have the best fuel gauge you have ever had.

spargs · Posted: Mon May 07, 2012 5:22 pm Post subject:

Thanks for the advice guys. I will look into the balance hose but must admit i am trying to avoid fittings at the bottom of the tanks due to leaks.

I'd far prefer to have all fittings coming out from the top panel of the tank. I would do as JayGee suggests but the issue with the diesel is the return line - i dont think a T fitting would evenly return the fuel to each tank.

Will keep looking at my options and appreciate the feedback thus far.

JayyyyGee · Posted: Mon May 07, 2012 5:35 pm Post subject:

Quick Q

R the tanks below deck

_________________
**************************
Save The Fish, Eat a Pussy Cat

spargs · Posted: Mon May 07, 2012 5:53 pm Post subject:

Yep they are sub floor tanks below deck...

JayyyyGee · Posted: Mon May 07, 2012 6:15 pm Post subject:

Good they wont give you a weight tranfer prob like if they were above floor

sparg i wouldn't even worry to much about uneven weight depending on type of fishing you are doing just use system i descibed & use valves to swap tanks every hr or so.

Personally i'd be runing one tank dry moreso to circulate fresh fuel on board

But not knowing the boat or layout & if i were concerned about uneven weight i'd get fitting welded to bottom of tanks good size ones around 40 mm

As suggested but run a 40 mm tube between & have one barb fitting Tee'd into it which will be feed out for both tanks no need for a 2nd feed out

Can even use ball valves coming from each tank pre T rather than on filter

This way only one return line required as well to either tank
_________________
**************************
Save The Fish, Eat a Pussy Cat

carplips · Posted: Mon May 07, 2012 6:34 pm Post subject: choice

Under no circumstances should you run balance lines that are gravity fed.
The engine you are using spargs , im assuming its the one you told me about , has a lift pump. Its quite simple really , buy filters for the application and follow the directions

That would be a pros advice......................or you could pretend its not dangerous and anyone should play with fuel systems , be they diesel or the seeminlgy slightly less dangerous petrols

_________________
If God wanted you to know everything , he would have made you a boat repairer.