Surge tank size

sebch · Post by **sebch** » Mon Feb 25, 2008 12:34 am

Hi,

I'd like to know the size (litres or gals) of the surge tanks you guys are using. I'll be using one for my next project and it'll have the return line plugged into it, so I believe it will not empty real fast. I thought around one liter would do the trick . What do you think?

Thanks, Seb

73Eldo · Post by **73Eldo** » Mon Feb 25, 2008 5:58 am

The ones I have seen for fairly stock applications have been in that size range. If you are using an internal electric pump dont forget that will take up some space also.

sebch · Post by **sebch** » Mon Feb 25, 2008 6:05 am

73Eldo wrote:If you are using an internal electric pump dont forget that will take up some space also.

No the pump will be outside and below the tank, so it'll never run dry.

Thanks for your answer! Seb

Jack · Post by **Jack** » Mon Feb 25, 2008 8:30 pm

Mine is about a 1/2 liter. It's a 1-5/8 dia tube about 9 inches tall.

Jack

73Eldo · Post by **73Eldo** » Tue Feb 26, 2008 6:07 am

Jack, is yours a production piece? Or did you make it or have it made?
A link or picture and more info would be handy if you have a chance to post.

Thanks!

Jack · Post by **Jack** » Tue Feb 26, 2008 7:48 am

It's a piece of chain link fence post <Blush>, with three pipe nipples welded to the side of the top and one to the side near the bottom.

Top nipples
- In from fuel rail return
- In from low pressure fuel pump
- Out to fuel tank

Bottom
- Out to the inlet of the high pressure fuel pump.

I built it tall to get some volume, but tall to insure that any bubbles coming from the fuel tank would return to the fuel tank and not get sucked up by the high pressure fuel pump. I seem to recall that I calculated that at 3 mpg, my car could run for 11 seconds on the capacity of this tank. This was more than enough, since it was a Street/AutoX car, not a road racer.

Jack

Edit - I'll PM some pics, as it's easier than posting. Also, It's a home built unit. I started with exhaust pipe, but was concerned about durability and also the weld quality between a pipe nipple and the much lighter sheet metal.

ChevelleFan · Post by **ChevelleFan** » Tue Feb 26, 2008 7:48 pm

Hi Jack,

I'd be interested in seeing those pics too if it's not too much trouble.

-Dave

David_S · Post by **David_S** » Wed Feb 27, 2008 4:46 pm

I used a 2L stainless steel tank 25cm x 10cm dia on my 4L 6cyl 4wd. I went for a tall 2L tank to ensure the fuel stayed cool while idling.

I put the inlet from the main tank 45mm below the return from the injectors, and the return to the main tank just above that. The intention being to encourage hot fuel to be returned to the main tank and the cooler incoming fuel to feed the external pump under the tank. See drawing below. Dimensions in mm

Seems to work well. A guy here fabricated it in polished stainless steel for about $US65 delivered and made a really nice job.

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