Fuel System Critique

[ShadowGrayGuy]

All,

Trying wrap up work on my '70 Chevelle so we can make it to some of the upcoming summer track events here in the Midwest. This is definitely a case of "learning as we go", as evidenced by the fact that I had the Rick's tank & fuel pump for 8 months before I found out you need to use a fuel pump controller with the A1000 on a street-driven EFI car (who reads the fine print first anyway?). I'm having "second thoughts" on the fuel system configuration. We already have all the parts shown in the diagrams below, so it's a question of which configuration would best suit the needs of the car. Car will be street driven, with some abuse on the track & local autoX events. Has a 4L80e controlled by an FAST/TCI EZ-TCU. Modern suspension & go-fast parts under a nearly-stock wrapper (sheet metal, paint & interior).

Option #1 (How the car is set up now):
http://i1216.photobucket.com/albums/dd364/linkewrc/ChevelleTechSupport/Fuel_Schematic1.jpg

Option #2 (cleaner look, but at the cost of performance?)
http://i1216.photobucket.com/albums/dd364/linkewrc/ChevelleTechSupport/Fuel_Schematic2.jpg


Here's a shot of the engine/fuel system as currently set up. Final configuration will have a cowl induction air cleaner fabbed to fit the FAST throttle body and clear the throttle linkage to help complete the almost-stock look.
http://i1216.photobucket.com/albums/dd364/linkewrc/ChevelleTechSupport/2012-05-12_15-46-52_50.jpg

What do you think? Option #1 the best? Or is there no significant difference given the car won't be "full-on" race.

Rob

[Vegas69]

I'd put the regulator pre Y on the feed side and dead head it into both rails with the crossover hose/tube in front. Also, the return should be equal to the return. So I choose neither of your designs.

[Musclerodz]

I agree with Todd.

[ShadowGrayGuy]

I thought the regulator was supposed to go after fuel rails so that the injectors would see full pressure/flow from the pump. I think your suggested configuration would make for a cleaner look and minimize the appearance of the EFI - which is a goal of mine.

I've seen some guys suggest mounting the regulator all the way in the back just outside of the tank and deadhead it all the way to the front of the car. What are the impacts of that configuration? Will the car take longer to start or will the fuel pressure stay in the line under this configuration?

Rob

[MaxHarvard]

Your filter placement confuses me. In my experience, it should be right after the pump on the feed side if the pump is in the tank.

[speedjohnston]

Option #1 looks fine to me. I believe that is almost exactly how Aeromotive recomends you do it. :cheers:

[SuperB70]

Same song. #1.

There you feel both rails at same end and out the other. Second options was big down side, if you run in to fuel delivery problems, your lambda show ok but you will melt your right bank pistons.

Only thing I'd chance is the nylon hoses to teflons one, they hold ethanol and E85.

My current project was #2 when came in but I'm chancing it to #1 with teflon hoses.

[ShadowGrayGuy]

Your filter placement confuses me. In my experience, it should be right after the pump on the feed side if the pump is in the tank.

Sorry - my diagram isn't to scale. I had planned to install the 10 micron filter on the inside of the passenger frame rail just in front of the rear wheel; maybe 3 feet "downstream" of the in-tank pump (which has a 100 micron filter on the bottom of it, I believe).

I've been intrigued by the various threads/discussions about dead heading the fuel line out to the engine, but didn't know if it was something that could/should be done on this type of set-up; seems like I see discussion about it used on LS engines, but I haven't seen anyone use it on a big-cube BBC. Is there a reason or is the routing more of a personal preference issue?

[bentfab]

System one is the way to go. In all my experience's and dealing with the customers wants and needs. System one is the most common. Every one always try's to get technical and tell you this and that or thats wrong and this is right. I've plumbed every conceivable way and never had anyone tell me they had a problem. From 2000HP Nelson motors to 200hp small blocks. I've done dead head systems as well,but it's not really a dead head because there is still a return style regulator back by the tank. The customer insisted we do it that way and the tuner would adjust the injectors and set-up according to the demand of the motor. Thats what I was told so that's what I did.

I think the best way w/ an A1000 is to run a -10 feed w/100 micron pre filter up to a -10 micron post filter(usually as close to the front so I can route a hose from the frame to the motor) into a tee or one of my distribution blocks and out to each rail with a -8 line to feed the front side of the rails. Then out the back of the rails into a regulator. Out of the regulator back to the tank with a -8 line. Or vise versa depending on space and looks. Supper simple and strait forward.

The biggest thing is to make sure your system has the least amount of bends and 90s as possible and to make sure not to bottle neck the system with different size fittings and hose. Just remember if you have a small fitting coming out of the tank or some where else in line that's going to be the size of your system and could choke the entire set-up no matter how big a line you have. I hope this makes sense and helps.

Here's a few pics to look at

Mark

[ShadowGrayGuy]

Thanks for the input ( & engine eye candy!:wow: ), Mark. Also thanks to those who were kind enough to NOT post how I have my regulator plumbed wrong. Got a PM from a member pointing out that I should have two -8 lines running into the sides of the regulator and the -8 return to the tank on the bottom of the regulator (see engine pic in my initial post). How embarrassing!

What is everyone doing in terms of fuel line type from the tank up to the engine compartment? I have nylon braided hose (as you see in the picture) from Jegs or somewhere similar. I thought I read on the forum that this will produce a gas smell no matter how tight I've got the fitting? What's the best way to plumb it to the front? Rigid stainless steel lines?

Rob

[SuperB70]

I've always used hardlines. Mostly from soft aluminium from Allstar they sell it with 25ft coil, 3 different sizes. Jig fittings.

Also have made from thinwall stainless, from 1/2" titanium, once ( really hard to bend) chance them to aluminium and also from zinked steel.

All have worked fine. Just make sure that they are fasten good so they wouldnt vibrate and crack.

[bentfab]

Thanks for the input ( & engine eye candy!:wow: ), Mark. Also thanks to those who were kind enough to NOT post how I have my regulator plumbed wrong. Got a PM from a member pointing out that I should have two -8 lines running into the sides of the regulator and the -8 return to the tank on the bottom of the regulator (see engine pic in my initial post). How embarrassing!

What is everyone doing in terms of fuel line type from the tank up to the engine compartment? I have nylon braided hose (as you see in the picture) from Jegs or somewhere similar. I thought I read on the forum that this will produce a gas smell no matter how tight I've got the fitting? What's the best way to plumb it to the front? Rigid stainless steel lines?

Rob

Thanks Rob. I've always plumbed everything in hardline(thats what I do best:woot:) and plumbed in soft line where needed. It all depends on your wants,needs,time line and budget. As far as the smell I think there was an industry issue a while back with all the hose.

Mark

[67ragtp]

Here's how I plumbed mine, works nice, a1000 with #10 tank to pump and #8 up and back all PTFE lined. Rich

http://i168.photobucket.com/albums/u188/ragtp/Picture081.jpg

[J-440]

Plumbed mine just as you stated for option #1. I have my feed line going to the front under the intake, split with a Y fitting, then two -8 hoses. Also, Aeromotive said to do so.

[ShadowGrayGuy]

OK, so now you all have me wondering about fuel line routing & aesthetics. Should I stay with my original Option #1, with the mods shown below:

http://i1216.photobucket.com/albums/dd364/linkewrc/ChevelleTechSupport/Slide5.jpg

Or should I try and hide the fuel lines altogether and plumb stainless hard lines with 180s and take the fuel to a regulator/bypass relocated just behind the throttle body? (Option #2, below)
http://i1216.photobucket.com/albums/dd364/linkewrc/ChevelleTechSupport/Slide4.jpg

In the end, the intent is to have something quasi-stock looking, like the stock LS-6 in the photo below:
http://i1216.photobucket.com/albums/dd364/linkewrc/ChevelleTechSupport/original_LS6_chevelle_454_engine.jpg

Rich - I like the idea of mounting the regulator in the front of the thermostat housing, but I don't know if I have enough room.

Mark - I also like the hardline you show mounted up the back side of the engine block & heads. Question - do you have to worry about fuel heating with uninsulated lines that close to the engine?

Rob

Rob

[bentfab]

Mark - I also like the hardline you show mounted up the back side of the engine block & heads. Question - do you have to worry about fuel heating with uninsulated lines that close to the engine?

I don't think it affects it much,but that was on a car that wont be driven much and the customer wanted things clean but hidden. Those were hard line too. I usually put fire sleeve around all the soft lines that run up the back side of the motor or up and over the rear end. Here's a few more examples.

[preston]

I highly recommend using teflon hose for all soft fuel lines. Last I checked you could only go up to -8 just buying Aeroquip stuff from Summit/Jegs though. The larger stuff is out there but its harder to find. There was an excellent article in Hot Rod about a year ago about all the new killer teflon lines that were flexible and came in all sorts of sizes, but honestly I have not really seen them for sale although I wasn't plumbing fuel at the time so I never really sought out the vendors. I guess I just mean I haven't seen any of them doing any advertising.

I'm not sure what you mean by nylon hose - are you talking about the covering ? All butyl based hoses will have oder and deteriorate over time and should not be used for fuel unless you like to replace them every few years.

The Aeroquip teflon line is no picnic, its not very flexible and the fittings require olives and don't come in swivel style, but its the easiest way to go. I'd be happy if someone here could fill us in on the better alternatives.

[ShadowGrayGuy]

Me too - is everyone running hard lines (stainless steel) or are most folks doing what I am (didn't know any better :( ) and using the nylon-wrapped butyl rubber hoses (from Summit/Jegs as seen in my pic above)?

I'm 99.9% sure I have to run a -10 line from the tank to the engine where it splits to two -8 into the fuel rails. What is everyone else doing?

(With so much invested in the car at this point, I certainly don't want to skimp on the fuel delivery system at this point!)

Rob

[67ragtp]

I highly recommend using teflon hose for all soft fuel lines. Last I checked you could only go up to -8 just buying Aeroquip stuff from Summit/Jegs though. The larger stuff is out there but its harder to find. There was an excellent article in Hot Rod about a year ago about all the new killer teflon lines that were flexible and came in all sorts of sizes, but honestly I have not really seen them for sale although I wasn't plumbing fuel at the time so I never really sought out the vendors. I guess I just mean I haven't seen any of them doing any advertising.



Check out BMRS(brown and miller racing solutions) inner liner is 100% PTFE convoluted and smooth bore hose. I was really surprised at how flexible it is. Any size up to 24AN crimped, stuff can handle just about any fluid and pressure, these guys currently have almost every cup team, they dont mind working with the little guy. Send them garden hose templates and they are ok with it. The quality is awesome!
Rich

[J-440]

Those black nylon hoses are rated at 300psi and are great for gas/tranny and oil only. They don't like large amounts of heat. I wrap my hoses in thermosleeve just as they come up to the beginning of the header. I've also got my tranny hoses and oil line cooler hoses wrapped as well since my coolers are mounted up front. Very flexible and easy to cut.