LS7 Fueling
Author
Discussion

V8 Vum

Original Poster:

3,206 posts

245 months

Wednesday 24th August 2011
quotequote all
We can't stop fiddling can we! Well, I can't anyway! My setup used pretty-much the std pollock-valve system with reg before rails. But then I got to thinking (bad news!), and decided to change the circuit so that the feed from the swirl-pot/HP pump goes direct to the rails and then to the reg, then back to the top of the swirl-pot, then back to the tanks via the pollock-valves.

Since the std rails do not have a normal -6 second port, only a shrader valve, I did wonder if using this (with the valve inner removed)would result in too much of a restricted flow? can the whole valve body be removed and replaced, or is this necessary?

cheers


MarkWebb

983 posts

241 months

Wednesday 24th August 2011
quotequote all
you are thinking of plumbing it the way that I have. I do not recommend it! It will heat the fuel even more I think. Keep all swirl pots and pumps and regs as low as possible in the engine bay to keep cool. only send fuel to the fuel rails that is going to be used ie keep reg as is. Throw away crap pollack valve and buy 2 proper solenoid changeover valves. Fuel pump speed control will also help if anybody can produce a working system.

738 driver

1,202 posts

217 months

Wednesday 24th August 2011
quotequote all
By the time all the swirl pots, regulators, fittings, valves etc etc etc are purchased.. you could have dropped a pump in each tank and bought a proper electronic controller.. a real fuel on demand system.... quite simple too.

MarkWebb

983 posts

241 months

Wednesday 24th August 2011
quotequote all
738 Proper controller? I am not aware of an aftermarket one as yet. Only devices that have two speeds and very basic control ie a switch which can be triggered by ecu. Please enlighten me if you know differently.

V8 Vum

Original Poster:

3,206 posts

245 months

Wednesday 24th August 2011
quotequote all
Mark,

What problems were you having? I understood that having fuel flowing through and back to the tank was better than the other way? And even Aeromotive themselves seem to suggest that is the best way with their regs!

DW

The horse has already bolted!
Like many of us, as we build, we try to navigate our way around the many opinions here to try to arrive at the best (optimum) solution offered at the time, and I, like many have installed the factory valve (but a bigger swirl-pot) etc, so money already spent, and engine/gbox and everyting in place! Would hate to have to remove that lot unless I have to.

What is the problem with the factory valves?

738 driver

1,202 posts

217 months

Wednesday 24th August 2011
quotequote all
MarkWebb said:
738 Proper controller? I am not aware of an aftermarket one as yet. Only devices that have two speeds and very basic control ie a switch which can be triggered by ecu. Please enlighten me if you know differently.
Several options Mark, easiest I came up with for a stock motor was a low mounted header tank,
say 2-3 ltrs, gravity fed, probably in the lower left engine bay and drop in the lingenfelter camaro pump/controller combo unit. Good for up to 900 HP at 13V and programmable/tunable with a GM ecu.
..... is this not much simpler than yards of braided fuel hose, connectors, valves ...potential leaks...headaches ?

There are several simple methods out there to overcome the twin tank fuel hurdle.


The other common problem seen with installations/ running problems.....fuel pressure .
Some seem to think that setting the regulated pressure at idle is the way to go.... stick it on the dyno or rollers and watch what happens... insufficeint pressure and hence volume, under load. Have even seen experienced roller owner 'experts ' compensate a tune for this simple problem.. and charge big money for it!
Heat in the fuel system is the other culprit... when you combine insufficient volume/low pressure (and those LS's need plenty of both) with slowly building fuel temps a tune will go off very quickly.

So most manufacturers..... fuel on demand,, forget about returning hot fuel anywhere, if fact many monitor fuel rail temp and adjust the tune/delivery accordingly to suit density/pressure change.
More to success than plug n play..... if you want great results.


Edited by 738 driver on Wednesday 24th August 11:29

V8 Vum

Original Poster:

3,206 posts

245 months

Wednesday 24th August 2011
quotequote all
738 driver said:
Several options Mark, easiest I came up with for a stock motor was a low mounted header tank,
say 2-3 ltrs, gravity fed, probably in the lower left engine bay and drop in the lingenfelter camaro pump/controller combo unit. Good for up to 900 HP at 13V and programmable/tunable with a GM ecu.
..... is this not much simpler than yards of braided fuel hose, connectors, valves ...potential leaks...headaches ?

There are several simple methods out there to overcome the twin tank fuel hurdle.
Sounds great! So why haven't many other adopted this, including the factory?

738 driver

1,202 posts

217 months

Wednesday 24th August 2011
quotequote all
Must be thinking outside the norm again....apologies Keith.

V8 Vum

Original Poster:

3,206 posts

245 months

Wednesday 24th August 2011
quotequote all
738 driver said:
Must be thinking outside the norm again....apologies Keith.
I certainly did not intend to cast doubt on your suggestion if your thinking this..so apologies...

It does sound very effective, and certainly if no real down-sides, I would have thought it would catch-on. I definately agree that the factory system seems awfully complicated, very expensive, and if a better, more simple system is out there that really worked, I would go for it!
BUT - there has been masses of threads on here in the past, with loads of differing opinions and solutions, which only serves to totally confuse all but the experts IMO.

I don't like my existing complicated setup, I have had problems already, and I have not found the culprit yet...and my build is not even complete/ on the road!
However, the thought of ripping everything out now... the engine, gbox, and all the plumbing is in place, fills me with absolute horror and dread and could cost me another few months of delay (and money of course)!

My original question was surrounding the use of 'through flow' in the rails rather than the 'returnless' setup, the latter which appears to be less favored by Aeromotive themselves in an email to me.
Making things worse....there seems to be a big conflict of opinion on here regarding the efficacy of either system when combating the potential for 'hot fuel syndrome'!

...so I am more confused now that I ever was!

macgtech

997 posts

183 months

Wednesday 24th August 2011
quotequote all
The simplest solution is to fit a bigger tank in the left hand sidepod. Do away with the pollack valve and hey presto. Obviously you lose a bit of storage space, but if you remove the right hand tank you have a big chunk of space available for whatever you like (you could extend the LH storage bin backwards, for example.)

Jonny

738 driver

1,202 posts

217 months

Wednesday 24th August 2011
quotequote all
Keith as with many issues.. plenty of ways to skin ze cat.

Fuel companies like to sell fuel components... naturally.

Other suppliers like to sell their products including factories.... very normal

Large Motor Manufacurers like to sell cars that people will buy, meet regulation, performance expectation and not be back every five mins for warranty work. If you are in the business of selling 500-650 HP everyday runners (GM USA) you will have done some homework to meet the above.
IE keep it simple and reliable...

If you want to be different and sell lots of your products, dont follow GM's route.

MAC G's a great idea for a track car but most of my mates are not getting any lighter with age...listing down the road two up didnt appeal.

Edited by 738 driver on Wednesday 24th August 12:34

deadscoob

2,265 posts

284 months

Wednesday 24th August 2011
quotequote all
Jonny,

Do you have any pics of your setup?

I'm with Keith on this, I think the factory setup us overly complicated and there is a simpler way to do it. Reading everyones opinions has confused me further though.

I like the idea of intank pumps, but not the amount of bespoke fabrication needed. I wouldn't know where to start or who to startwith.


deadscoob

2,265 posts

284 months

Wednesday 24th August 2011
quotequote all
Jonny,

Do you have any pics of your setup?

I'm with Keith on this, I think the factory setup us overly complicated and there is a simpler way to do it. Reading everyones opinions has confused me further though.

I like the idea of intank pumps, but not the amount of bespoke fabrication needed. I wouldn't know where to start or who to startwith.


V8 Vum

Original Poster:

3,206 posts

245 months

Wednesday 24th August 2011
quotequote all
deadscoob said:
Jonny,

Do you have any pics of your setup?

I'm with Keith on this, I think the factory setup us overly complicated and there is a simpler way to do it. Reading everyones opinions has confused me further though.

I like the idea of intank pumps, but not the amount of bespoke fabrication needed. I wouldn't know where to start or who to startwith.
he love his response soooo much...he did it TWICE!


macgtech

997 posts

183 months

Wednesday 24th August 2011
quotequote all
deadscoob said:
Jonny,

Do you have any pics of your setup?

I'm with Keith on this, I think the factory setup us overly complicated and there is a simpler way to do it. Reading everyones opinions has confused me further though.

I like the idea of intank pumps, but not the amount of bespoke fabrication needed. I wouldn't know where to start or who to startwith.
I don't have any pictures, however I can describe briefly what we did.

We needed a larger capacity tank that we could refuel quickly, whilst ideally removing as many components as possible for the sake of reliability (mainly the pollack).

We had a tank custom made that is essentially an extension of the non-driver side tank (LH in our case), and this was plumbed in in the usual way - we had an extra filler/vent put at the front to be compliant with the regulations. Ralloy in North Yorkshire made our tank for us.

The pollack and associated hosing was removed, so the line ran from the tank straight to the pump, then up to the swirl pot etc.. The redundant tank (driver side) was also removed - this has helped with access to the engine bay no end and also improves airflow.

We spent a lot of time thinking about how to achieve what we wanted - we obviously had some further requirements (dry break refuelling, large capacity etc) to consider, and the only two downsides are the loss of storage space in the RH compartment and the fact that the coolant pipe runs close to the tank. However this is heavily lagged and the tank is heat shielded so should not have too much of an effect.

MarkWebb

983 posts

241 months

Wednesday 24th August 2011
quotequote all
Unfortunately I do not have a GM ecu to work with the Lingenfelter controller and cannot fit one to my old school small block.
Fuelabs who make the prodigy fuel pump range which has a PWM input are building a regulator which electrically senses pressure and controls the fuel pump.
This seems to be the best bet for a stand alone solution to cure overheating fuel.

V8 Vum

Original Poster:

3,206 posts

245 months

Wednesday 24th August 2011
quotequote all
Back on topic....

Can the whole schrader valve body on the std LS7 fuel rail be removed and replaced with a bigger bore fitting, or is this necessary for a 'return system'?

MarkWebb

983 posts

241 months

Wednesday 24th August 2011
quotequote all
Don't think it will be big enough Keith. Why do it anyway? LS7 fine with return-less system. See my email to you.

Gulf LS3

1,922 posts

228 months

Wednesday 24th August 2011
quotequote all
deadscoob said:
Jonny,

Do you have any pics of your setup?

I'm with Keith on this, I think the factory setup us overly complicated and there is a simpler way to do it. Reading everyones opinions has confused me further though.

I like the idea of intank pumps, but not the amount of bespoke fabrication needed. I wouldn't know where to start or who to startwith.
Hi Craig no mods are required, it really is as straight forward as 738 says, he doesnt like wasting money so comes up with some very simple solutions to save him opening his wallet.

Have you got your tanks yet? A big link pipe is a must and saves a lot of plumbing

deadscoob

2,265 posts

284 months

Thursday 25th August 2011
quotequote all
Just about to order today as it happens. What sized link pipe is required?

Cheers