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Discussion Starter · #1 ·
I'm in the process of designing a fuel system for my LS1 conversion. I mocked up some of the components last weekend and I finished the mounting plate today, escept for paint. I'll be test fitting the tank and fuel system on the frame tomorrow and taking some more pics, but I think thesystem is going to work OK. The plate is mounted to the crossmember that supports the front of the tank.

:cheers:

Rick B.



 

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Why two pumps in series with each other???

can't see it does anything....
 

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Discussion Starter · #3 ·
The one on the left is a pre-filter between the tank and the pump. The inside of my tank looks pretty clean but I figure if I'm recirculating fuel from the C5 filter/reg any rust or junk in the tank is going to get stirred up. I'd rather have the junk end up in a cheap filter than an expensive pump.

:cheers:

Rick B.
 

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Discussion Starter · #4 ·
Here are a few more pics with the fuel system mounted under the tank. It looks like there will be no interference when the body is back on but if there is I can move the plate back toward the rear of the car.

:cheers:

Rick B.





 

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The one on the left is a pre-filter between the tank and the pump. The inside of my tank looks pretty clean but I figure if I'm recirculating fuel from the C5 filter/reg any rust or junk in the tank is going to get stirred up. I'd rather have the junk end up in a cheap filter than an expensive pump.

:cheers:

Rick B.
OK, the obvious filter on the left, and a pump in the middle, no rocket science...but then that unit on the right with the crazy modern fittings is another filter intended for injectiion??? why the grounding strap off a fule filter....?? which is why I assumed it was another pump...
 

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Gene its a fuel filter/regulator for 99 and up c5 vettes.its whats used to regulate the fuel and a filter also.This way you just run one line to the front for feed and the return is a short line coming off that filter right back to tank.
 

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Discussion Starter · #9 ·
Maybe I'm not seeing this correctly. Is that rubber line coming off the pump?
I may do something fancier if I can find a fitting that will screw into the pump outlet and has a Quick Connect on the other end. The 2 fittings are almost touching inside the hose and it is FI hose. I'll definitely have the fire extinguisher on hand the first time I start this thing. :laughing:

:cheers:

Rick B.
 

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Discussion Starter · #10 ·
OK, the obvious filter on the left, and a pump in the middle, no rocket science...but then that unit on the right with the crazy modern fittings is another filter intended for injectiion??? why the grounding strap off a fule filter....?? which is why I assumed it was another pump...
I didn't realize the filter/regulator is what you thought was a 2nd pump or I would have explained before. The bracket comes with the C5 filter and an extra ground on the fuel system is a great idea. I'll probably run a wire from the filter bolt to the frame so I don't have to scrape a lot of paint off the crossmember and frame to get a good ground connection.

:cheers:

Rick B.
 

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I didn't realize the filter/regulator is what you thought was a 2nd pump or I would have explained before. The bracket comes with the C5 filter and an extra ground on the fuel system is a great idea. I'll probably run a wire from the filter bolt to the frame so I don't have to scrape a lot of paint off the crossmember and frame to get a good ground connection.

:cheers:

Rick B.
OK, why ground any fuel filter/regulator?? what differance can it make??

second off does that regulator have a vac line to the manifold??

if not, I would have to suppose the LS engines do not need any vac source to change fuel pressures, and metering it done entirely through PWM of the injectors... NO??
 

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Discussion Starter · #12 ·
OK, why ground any fuel filter/regulator?? what differance can it make??

second off does that regulator have a vac line to the manifold??

if not, I would have to suppose the LS engines do not need any vac source to change fuel pressures, and metering it done entirely through PWM of the injectors... NO??
I think the early Camaro LS1 engines had the regulator at the fuel rail and had a return line back to the tank. The C5 filter has the regulator built into it so it will supply a constant pressure to the fuel rail without the need for a long return line. Pretty good deal for $45. I suppose the ground is there as a safety precaution. If the pump leaks internally shorts out for some reason the ground could prevent current from entering the fuel system and arcing somewhere.

I'm not intimately familiar with the LS1 ECU (yet - I'm sure I will be by the time it's on the road) but there are so many connectors on the fuel injection harness that I'm sure the fuel pressure is being tracked somewhere. There is no vacuum line to the regulator.

:cheers:

Rick B.
 

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Thanks for posting the pictures, I have been looking for ideas. I am going with a TPI manifold and still havent figured out how I will run the fuel system.
 

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Discussion Starter · #14 ·
Thanks for posting the pictures, I have been looking for ideas. I am going with a TPI manifold and still havent figured out how I will run the fuel system.
My Camaro LS1 inlet is on the driver side so I'm going to run the fuel line where the evaporative line used to run, parallel to the brake line. I think Vette fuel rails have the inlet on the drivers' side. Use the original fuel line if you can. Saves a lot of fabrication.

:cheers:

Rick B.
 

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Use the original fuel line if you can. Saves a lot of fabrication.

:cheers:

Rick B.
Rick,
I thought you had to use a larger diameter line for EFI?
My biggest issue is trying to figure out how to mount an in-tank pump. That scares the heebygeebys out of me. I like what you came up with.
 

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Discussion Starter · #16 ·
Rick,
I thought you had to use a larger diameter line for EFI?
My biggest issue is trying to figure out how to mount an in-tank pump. That scares the heebygeebys out of me. I like what you came up with.
3/8" is supposed to be adequate for EFI. I think the original line from the tank is 3/8" - at least the hose fits on both ends on my design. The return line is only 1/4" for the mechanical pump system. I'm going to run a new 3/8" line down the drivers' side where the evaporative line used to go but I need to buy new brake lines first since the 2 lines run together along most of the frame. My goal is to not drill any more holes than I have to. If you have a later model year you might be able to put in an in-tank pump. My 79 had the fuel outlet at the top of the tank. The 72 has nothing on top but the filler.

I have been concerned about noise and vibration from the electric pump but my son pointed out that once the engine is started we probably won't be able to hear the pump anyway. We're not going for neighbor-friendly on this build. :laughing:

:cheers:

Rick B.
 

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72LS I can guarantee you I don't know jack about the LS series engine....

BUT I have had DPFI on my 355 here for ten years now...running ~42 PSI and it can run down to 35 or so PSI if I want it to.....by adjusting the regulator....

I am using the ORIGINAL LINES 3/8 supply, and 1/4 return....works fine, never once proven a problem....since the supply can support about 500 hp or so, the minimum is fine for idle, even on my ~375 hp engine, I fail to see where running new lines is any advantage.......except for obvious failures....


like RUST....
 

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Discussion Starter · #18 ·
72LS I can guarantee you I don't know jack about the LS series engine....

BUT I have had DPFI on my 355 here for ten years now...running ~42 PSI and it can run down to 35 or so PSI if I want it to.....by adjusting the regulator....

I am using the ORIGINAL LINES 3/8 supply, and 1/4 return....works fine, never once proven a problem....since the supply can support about 500 hp or so, the minimum is fine for idle, even on my ~375 hp engine, I fail to see where running new lines is any advantage.......except for obvious failures....


like RUST....
The Camaro fuel rail feeds from the drivers' side so I want to avoid having to run a line in back of the engine to make the connection. If I were using a Corvette fuel rail I'd be all set because they feed from the pass. side.

I'm doing all the plumbing on a bare frame so I have the luxury of space to route the lines. If I were doing this on a body-on I would use the original lines.

:cheers:

Rick B.
 
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