Big Stu
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| posted on 9/2/09 at 01:46 PM |
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Fuel pump recomendations injection.
Hi All,
I am about to install a 3.9 rover v8 injection into my land rover, which is currently a carbed 3.5. The only problem which I can forsee at present is
the fuel pump.
Currently I have a facet pump sucking from the tank via an 8mm outlet then pumping up to the carbs.
I need to deliver fuel to the engine about 4 - 5 bar. The facet pump obviously can't do this. Therefore I need to install an HP pump. My idea is
to keep the facet pump to deliver fuel to the engine bay and install an injection pump here. This will reduce the risk of running HP hoses and the
cost of aeroquip hose.
Can anyone see any problems with this or suggest a suitable injection pump and filters. Or a injection pump that is capable of sucking fuel from the
tank.
I do have another 8mm outlet on the tank I could use to double up the supply voloume.
Cheers
Stu
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John Bonnett
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| posted on 9/2/09 at 02:10 PM |
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Hi Stu
I used an injection pump (Bosch) from a 2 litre Astra on the Cossie fitted to my Phoenix. I paid 25 quid for it together with the filter all mounted
on a little subframe from a breakers in the late 90s and it has performed without any trouble ever since. I see no reason to buy new.
I think pumps of this type need to be gravity fed or from a l/p pump. I installed my pump below the tank which was modified to have a small swirl
tank.
atb
John
[Edited on 9/2/09 by John Bonnett]
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BenB
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| posted on 9/2/09 at 02:18 PM |
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Why 5 bar? That's damn high pressure? Are you running boost (ie need 3 bar relative to boost). 2.5-3 bar is normal otherwise!!
I'd do as you plan IE keep the facet for the LP stage, have a swirl pot, and use a high pressure pump from there in. IF you go on Ebay there are
lots of cheap aftermarket pumps for about £30 and they state their flow rate (usually stated @ 3 bar though)....
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Big Stu
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| posted on 9/2/09 at 02:23 PM |
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Sorry got my conversions mixed up. It needs to be about 40psi which is less than 3 bar.
The bottom of my tank already has what I would call a swirl pot. (4" tube about 3" deep) The pick up hoses go into this. Would an 8-mm
pipe be ok on the suction or do I need to increase this, or use two of them?
[Edited on 9/2/09 by Big Stu]
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zetec
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| posted on 9/2/09 at 04:48 PM |
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I'm the same...£25 s/h Vauxhall GTE pump, 8000 miles and 6 years without a hitch. Make sure you fit a decent pre/post pump filter, my post pump
filter is 8mm in/out from a Carlton. Pump has 1/2" in and 8mm out if I remember right. Fit it under the tank as it is unable to suck fuel. I did
all my runs in 8mm copper tube with solder on olives fitted at the ends where the rubber tube connects....no need to go to the cost of aeroquip all
the way...just fit it in the engine bay if you like the look!
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owelly
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| posted on 9/2/09 at 05:09 PM |
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I've used a pump/swirl pot from a Golf GTi. It came with the HP pump mounted in a plastic swirl tank and the HP filter canister all neatly
bundled together. The tank has the vapour vent/return and everything all built in. I was goin to pay £20 until some one gave me one for free.....
http://www.ppcmag.co.uk
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martyn_16v
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| posted on 9/2/09 at 08:16 PM |
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quote:
Originally posted by Big Stu
My idea is to keep the facet pump to deliver fuel to the engine bay and install an injection pump here. This will reduce the risk of running HP hoses
and the cost of aeroquip hose.
I'd keep it simple and have a single high pressure pump. You will need to run a return line to the tank anyway, you could use the old feed as
the return line and then you only need to fit one high pressure line. It doesn't have to be expensive aeroquip hose, plain rubber fuel-injection
hose isn't that expensive and you can use copper microbore central heating pipe for hard lines.
The Golf GTI pump unit is a good shout if you've got the room, I was going to use one on my Indy but couldn't find anywhere to put it. If
you get one from an early (up to '89) mk2 8v GTI or a mk2 16v it's a bit manlier than the later 8v pumps, but needs to be below tank level
as they had a separate in tank pump in the Golf. The later (Digifant injection) 8v GTI had a single pump but it doesn't flow quite as well as
the early ones.
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britishtrident
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| posted on 9/2/09 at 08:49 PM |
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3 bar is more or less the standard for normally aspirated injection systems --- normally the pump can produce more than that say 4.5 bar and the
regulator dumps the surplus back to the tank. The pump must be big enough to let the regulator supply constant 3 bar to the injectors even when the
loud pedal is floored.
Trouble most OEM pumps are in tank --- and you need a fairly big pump probably slightly bigger than an engine of equivalent output but smaller
capacity.
ISTR the XR4i and Granada injection models used and external pump
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