deadhead Fast rails
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deadhead Fast rails I'm about to install an LS with Fast rails in my C5. Due to the space available (or lack of space) at the back of the engine / under the cowl, it would be pretty convenient to block off the backs of the fuel rails and just feed them from the front. The stock fuel rail deadheads four sets of two injectors, which gives me hope that this could work... But I don't know what I don't know.
Is this a terrible idea? Am I asking for headaches if I do this? Should I bleed the air from the backs of the rails before I fire it up?
Fuel flow would be:
pump >> regulator >> Y >> fronts of both rails >> plugs at the backs of the rails
...with the regulator's return line going back to the tank, and each rail feeding four injectors of course.
Thanks!
Is this a terrible idea? Am I asking for headaches if I do this? Should I bleed the air from the backs of the rails before I fire it up?
Fuel flow would be:
pump >> regulator >> Y >> fronts of both rails >> plugs at the backs of the rails
...with the regulator's return line going back to the tank, and each rail feeding four injectors of course.
Thanks!
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On one of my LS swaps I ran the fuel line up to the back of the intake. Added a "Y" in the fuel line and then two short lines to the fuel rails. Plugs in the front of to fuel rails. I used a C5 FFR back near the tank for the return.
It ran fine. The engine was a rebuilt LS6 with a small cam. Not monster HP but again it ran fine.
It ran fine. The engine was a rebuilt LS6 with a small cam. Not monster HP but again it ran fine.
I think you typically want the regulator after the fuel rails so it is not a flow restrictor to the rails, but is still effective at setting rail pressure. I don’t think there is any reason for air bleed.
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The regulator will still be downstream of the rails. Think of it like putting the rails on T fittings upstream of the regulator.
What power level are you at? Are you boosted? You can get away with running a, less than optimal, routing on lower power stuff. Big power, especially FI, it's best to do it correctly. You can starve injectors at the end of the system.
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LS3ish NA 454, made 690 on an engine dyno so I'm guessing 600-625 at the wheels.
I'm not too worried about starving the injectors since I've got way more fuel pump than I need (TI / walbro 450).
I mostly just wonder if air is going to hang out at of the far ends of the fuel rails and cause random trouble.
I'm not too worried about starving the injectors since I've got way more fuel pump than I need (TI / walbro 450).
I mostly just wonder if air is going to hang out at of the far ends of the fuel rails and cause random trouble.
