BC

I had thought that a surge tank was plumbed into a fuel system so that it would recieve low pressure filling from the main tank, and then the high pressure pump draws from the bottom and goes to the fuel rail.

From there, the non-used fuel goes back to the MAIN tank, and it continues to fill the surge tank.

Is this not true?

I saw a drawing where the surge tank also gets the unused fuel from the pressure regulator.

I am confused now, as this is not the way I have imagined my system.

BC

Wouldn't the second way heat up the small amount of fuel too much?

Geoffrey

You can plumb it either way, however, by returning the fuel back to the main tank rather than the surge tank, you minimize the heating effect of the returned fuel.

BC

Ah. So I have the option. Very good.

Thanks.

Geoffrey

Here is a link to a thread I posted on the installation of a surge tank with in tank pumps into my fuel cell.

BC

I was thinking of that but I think I have enough room for an external surge, and also I can't (or don't think I can...) use intank pumps with ethanol.

Geoffrey

When researching e85 I spoke with the corvette team and they have been running in tank pumps with no issues. Their fuel is e60.

BC

Interesting. The research (albeit not speaking directly to people) I found was that the internal seals expand and let ethanol into the windings.

Will you be using E85 afterall?

RedlineMan

BC

Thats basically what I am trying to put together. I found an ethanol compatible low pressure pump for the transfer pump, and then I planning on a Tall but skinny surge tank to add some extra capacity.

I like that idea where you attached bungs to the tank to hold the fuel pump. Did you make that tank yourself or did you buy that?

RedlineMan

Hey;

Now, you know the answer to that. I must have been a farmer in a previous life. Never buy anything that you could make instead, and quite preferably out of a bunch of old junk laying around! The 2nd tank is 8x8x8 and approx. 2.21 gallons. The transfer pump ideally should be closer to the source, and even a bit below it, but the cell is already as low as it can be, and that Holley pump will self-prime from dry almost instantly, so...

I know it works well because I used to have to refill after every session or it would sputter in the next, even with 12 gallons available. In other words, I was not getting nearly all that capacity before it would starve. I also knew that Murphy would get me if I used an internal pump. I just KNEW it!

Geoffrey

John, did you install a bladder and foam in your second tank? Or is it just an aluminum can?

BC

I am buying a similar pump to that holley. I was going to go from main tank, to pump, through 50 micron filter, to surge, and have it over fill into the main obviously, and then have another, finer filter be on the pressure side to the main rails. Return from rails will go to main tank. I will have to use SS hard line for most of this, but I can also use Teflon lined SS line. but that increases cost alot - as long as I can bend the SS tuning (.035 wall) I can keep the cost doen to just the swag backings and nuts and some fittings I already have.

RedlineMan

Hey;

The only openings are those that the fuel passes through.

RedlineMan

If you trace my system, that is what you will find.

And the weight. A lot of people get hung up on braided SS, but it is almost always overkill. It is expensive, heavy, hard to work with (relatively), and is also very abrasive. The only braided I used was from the Bosch pump to the OE filter. The rest is "plug & play" rubber; plenty of performance, easy to deal with, and relatively cheap.