LS7 fuel system
Discussion
Spid said:
Looking at the factory layout for the fuel system, along with filters pump and reg there is a valve assembly, is this an Ultima part?
If they are still using a Pollak valve then no! You can buy them from biotuning.co.ukhttp://www.biotuning.co.uk/PartsValves.htm
Regards Dave
ultimaCZ said:
dont forget to include a swirl pot, otherwise you will get fuel starvation on the LS7 once the tanks are less than half full, mainly under hard acceleration. (have learned that the hard way and must now redesign the fuel system which is no fun if I dont want to take out the engine)
Does not show a swirl pot, I need one then?ultimaCZ said:
dont forget to include a swirl pot, otherwise you will get fuel starvation on the LS7 once the tanks are less than half full, mainly under hard acceleration. (have learned that the hard way and must now redesign the fuel system which is no fun if I dont want to take out the engine)
Why is this? I think I've noticed this same thing on my LS7 powered GTR.Paul
Ive just re-done my fuel system to ensure I dont ever have this problem...
I have 2 x -12 connections at the bottom of my tanks
I have both of these linked.
In one of these links I have a tee.
I have a Mallory high volume pump drawing from the tee and pumping into a swirl pot.
The swirl pot feeds a Walbro 225 High-Pressure pump.
Between the Mallory pump and the swirl pot I have a 5psi sender - this is linked to a light on the dash. If the light comes on I have a swirl-pot full of fuel left.
The swirl pot overflow goes to one tank and the fuel rail return goes to the other.
I have 2 x -12 connections at the bottom of my tanks
I have both of these linked.
In one of these links I have a tee.
I have a Mallory high volume pump drawing from the tee and pumping into a swirl pot.
The swirl pot feeds a Walbro 225 High-Pressure pump.
Between the Mallory pump and the swirl pot I have a 5psi sender - this is linked to a light on the dash. If the light comes on I have a swirl-pot full of fuel left.
The swirl pot overflow goes to one tank and the fuel rail return goes to the other.
I had a similar issue with my LS7 SL-C at the Run and Gun event a month ago...cost us 3 secs a lap doing split time checks.
I now have twin pick ups and a swirl tank....we did find we had a faulty fuel rail and a bad knock sensor too but that too has been replaced....and this was on a brand new GM crate engine....
I now have twin pick ups and a swirl tank....we did find we had a faulty fuel rail and a bad knock sensor too but that too has been replaced....and this was on a brand new GM crate engine....
crafty said:
Ive just re-done my fuel system to ensure I dont ever have this problem...
I have 2 x -12 connections at the bottom of my tanks
I have both of these linked.
In one of these links I have a tee.
I have a Mallory high volume pump drawing from the tee and pumping into a swirl pot.
The swirl pot feeds a Walbro 225 High-Pressure pump.
Between the Mallory pump and the swirl pot I have a 5psi sender - this is linked to a light on the dash. If the light comes on I have a swirl-pot full of fuel left.
The swirl pot overflow goes to one tank and the fuel rail return goes to the other.
Makes sense, wont need a valve to switch between tanks, and only need one sender for the fuel gauge.I have 2 x -12 connections at the bottom of my tanks
I have both of these linked.
In one of these links I have a tee.
I have a Mallory high volume pump drawing from the tee and pumping into a swirl pot.
The swirl pot feeds a Walbro 225 High-Pressure pump.
Between the Mallory pump and the swirl pot I have a 5psi sender - this is linked to a light on the dash. If the light comes on I have a swirl-pot full of fuel left.
The swirl pot overflow goes to one tank and the fuel rail return goes to the other.
All works well I take it?
Going to make the tanks myself, so putting 2 connections at the bottom won't be a problem.
I too have suffered with fuel starvation on an LS1. It is 99% track use so this doesn't help. Having tried loads of different ways of running 2 tanks I resorted to using just one tank with 2 red top competition pumps feeding a 2litre swirl pot with a Bosch high pressure pump to the rail with the pressure regulator at the end of the rail. The return from the regulator and swirl pot both return to the tank. If you are running two tanks on track, you will need to install non-return valves in the link pipe otherwise you end up with a very very full nearside tank - not good especially if it starts to discharge fuel on the n/s rear tyre or all over the track. Depends what you are using it for - if is road use only the advice the other guys are giving is spot on - but be very careful if you intend to track it - misfires, running lean and mid bend power loss are all bad news. If you are building the tanks yourself, try and baffle them as well as possible but also get the pick up pipe as close to centre and as low as possible - the ultima tanks have the pick up very close to the wall of the tank.
San Diego GTR said:
Does anyone have a link to a source of swirl tanks? I guess I'm hearing that you need a pump(s) before the swirl tank and another one after the swirl tank.
Paul
try http://www.atlltd.com/internal.htmPaul
It is the item No ITC305
Seems to be best suited. Have one on order.
Peter
SM-Engineering (based in UK) did a great job with mine--> http://www.sm-engineering.co.uk/
3x -6 inlets, 1x -10 outlet and a -8 return. 250mmx100mm
3x -6 inlets, 1x -10 outlet and a -8 return. 250mmx100mm
Edited by RussF on Friday 12th December 12:36
sm-engineering here in the UK do a round pot with JIC fittings for £62.
I want one that fits against the bulkhead like the flat oil catch tank SM also do.
SM are going to make me a bulkhead mounted, flat, fuel surge tank for about the same money. Only remains for me to send off the sketch of where I want the fittings.
They also said they could do the round tank with a bulkhead mounting flange if I wanted.
Steve
I want one that fits against the bulkhead like the flat oil catch tank SM also do.
SM are going to make me a bulkhead mounted, flat, fuel surge tank for about the same money. Only remains for me to send off the sketch of where I want the fittings.
They also said they could do the round tank with a bulkhead mounting flange if I wanted.
Steve
RussF said:
SM-Engineering (based in UK) did a great job with mine--> http://www.sm-engineering.co.uk/
3x -6 inlets, 1x -10 outlet and a -8 return. 250mmx100mm
Russ3x -6 inlets, 1x -10 outlet and a -8 return. 250mmx100mm
Edited by RussF on Friday 12th December 12:36
Was your for an LS7 config? If so have you got any diag or pics as to how you connected it up to the fuel lines?
Oh, and where did you mount it?
cheers
keith
Edited by V8 Vum on Friday 12th December 13:50
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