fuel system

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alanius
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fuel system

Post by alanius »

Hello,

We have a land rover light weight hybrid, build it 10years ago. But like every project it is never finnished and you're always upgrading.

4years ago we went from a 3.5 V8 twin carb to a 4.0 V8 EFI engine (thor intake) with stand alone motormanagement.
We had to change the fuel system to a high pressure fuelpump (Bosch 0580254979).

The problem we have is that we still use the original light weight petrol tanks under the seats. So we need a valve to switch between both tanks. At that time and later, I couldn't find a proper 3way valve to replace the original light weight valve.
The original valve uses a small diameter hose, think it is 5mm (estimate), what I guess is to small for the engine. Probably 8mm will be much better?

I just found the following 3way valve on the internet, any one has tried them allready or knows it is good or do you have another solution?
http://i.ebayimg.com/images/g/nAcAAOSwP ... s-l300.jpg

This is the original valve, can't modifie the internals unfortunatly:
http://www.land-rover-lightweight.co.uk ... %20C_O.jpg

Second question:

There is probable 3m of hose between the fuel tanks and fuelpump. is this to much for the pump to suck up the petrol or not?

All hoses are goodrich incl fittings, started from the pump to the engine and back to tank. Just the hoses to the pump are normal.

hope you understand my questions.
Many thanks for the information.

Regards
Alain



DaveEFI
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Post by DaveEFI »

IIRC, that type of pump is mounted under the tank so gravity fed. If you need to mount it above the tank, you add a second low pressure pump before it. The gravity feed pipe size is normally 1/2".
Dave
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alanius
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Post by alanius »

Thanks for the information, didn't know this was gravity fed :oops:
Pump is mounted above the tank, probably 30 - 40cm above the top of the tank.

What type of pump would you recommend to use for this application, low pressure?
I have to fit it after my 3way valve to get the fuel out of both tanks.

Any thoughts on the 3way valve?

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Ian Anderson
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Post by Ian Anderson »

http://www.ebay.co.uk/itm/Pollack-42-15 ... Swx6pYpehc

The Pollack valve is probably what you need.

You could also do it with solenoid valves from a Jag XJ6

Remember with fuel injection you need a return line to the tank so you need to make sure the fuel is returned to the tank from which you are drawing, or you will over fill the opposite tank and spill fuel

Ian
Owner of an "On the Road" GT40 Replica by DAX powered by 3.9Hotwre Efi, worked over by DJ Motors. EFi Working but still does some kangaroo at low revs (Damn the speed limits) In to paint shop 18/03/08.

unstable load
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Post by unstable load »

Why do you need to select between the tanks? Couldn't you just T them together and solve your problem in a simple way?

If you don't do serious off-road work, why don't you consider relocating your pump to the same level as the bottom of the tank and run a longer line. It doesn't have to be right at the tank, just at the same level.

I assume it's the same basic set-up as the Series/Defender with the tanks under the seat box and outboard of the chassis rails, so there should be plenty of space inside the chassis rails around the gearbox and T/C to mount the pump safely.

If you don't like that idea, then have a look at this...
http://www.edelbrock.com/automotive/mc/ ... kits.shtml
Cheers,
John

alanius
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Post by alanius »

Ian Anderson wrote:http://www.ebay.co.uk/itm/Pollack-42-15 ... Swx6pYpehc

The Pollack valve is probably what you need.

You could also do it with solenoid valves from a Jag XJ6

Remember with fuel injection you need a return line to the tank so you need to make sure the fuel is returned to the tank from which you are drawing, or you will over fill the opposite tank and spill fuel

Ian
We have 1 return to one tank. SO we always use that tank first and when it is almost empty we switch over to the second tank.
So the fuel is pumped over the the 'main' tank aswell as you don't use all the fuel you pump to the engine.

System works fine, use it allready 10years like that :)

Thanks for the information!

alanius
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Post by alanius »

unstable load wrote:Why do you need to select between the tanks? Couldn't you just T them together and solve your problem in a simple way?

If you don't do serious off-road work, why don't you consider relocating your pump to the same level as the bottom of the tank and run a longer line. It doesn't have to be right at the tank, just at the same level.

I assume it's the same basic set-up as the Series/Defender with the tanks under the seat box and outboard of the chassis rails, so there should be plenty of space inside the chassis rails around the gearbox and T/C to mount the pump safely.

If you don't like that idea, then have a look at this...
http://www.edelbrock.com/automotive/mc/ ... kits.shtml
We do offroad a lot and do serious stuff with the light weight. And if you do overland trips (Poland, Roumenia...) you need the 90litres of fuel ;-)

T_piece isn't a solution as you don't know from which tank you take fuel and you will have problems with the return.

There isn't enough room to fit the fuelpump really close to the tanks, everything fits just.

thanks for the info!

unstable load
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Post by unstable load »

alanius wrote:T_piece isn't a solution as you don't know from which tank you take fuel and you will have problems with the return.

There isn't enough room to fit the fuelpump really close to the tanks, everything fits just.

thanks for the info!
If the 2 tanks are permanently linked the return line will simply settle to level between the tanks through gravity. The ony issue I can see is for serious angles of lean you will have a tank on the low side overfill and spill out the filler, so keeping the valve is probably a good plan.

The pump doesn't need to be very near the tanks, just at the same LEVEL as the bottom of the tank. You could put it in your rear crossmember if you wanted to, all it would mean is longer fuel lines.

I think you should look at the Edelbrock remote tank and maybe make something like that up locally, then you can put it anywhere you have the space to spare.
Cheers,
John

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