EFI Fuel Plumbing - Best Practices
 

Hi Everyone,

I’m Eric. Long time lurker, first time poster. I own a Four Winns U17 (Donzi Sweet 16 clone). It originally had an OMC fuel injected Ford 5.0l connected to a VP Cobra SX drive. I pulled the Ford motor a few weeks ago and purchased a 5.3 LS engine to replace it. I was inspired by Tim Moore’s twin 5.3 skater build.

I have a plan for nearly everything, but I’m struggling to figure out what fuel system to use. What do most people run on a fuel injected motor? Any help will be greatly appreciated!

I originally planned on using this surge tank setup:
http://i.imgur.com/BMKf9px.jpg

After more research, I think this is illegal per USCG/APYC standard 183.518 (Each opening into the fuel tank must be at or above the topmost surface of the tank). As I think the Surge/Swirl is considered a 2nd fuel tank.

Also, I read this post by Raylar found here.

I'm picturing this looks like this:
http://i.imgur.com/7xmcwIC.jpg

Can the high pressure pump be relied on to lift the fuel from the tank, thru the water/fuel separator? Does the Water/Fuel Seperator have enough capacity to provide fuel for a few seconds if the tank’s pickup goes dry due to slosh?

Another option is using an OEM option, such as Crusader's Fuel Control Cell.
http://i.imgur.com/OBTUnhA.jpg


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Here is the rest of the plan for those who are interested:

Engine
- Stock 5.3l LM4 engine from a Trailblazer
- Holley Fuel Injected Intake Manifold w/4150 throttle body. This moves the spark arrester from the front of the engine to the top. This helps with packaging in the small engine compartment…and I think it looks cool.
- Holley Fuel Rails to go with the above intake manifold.
- Holley HP ECU
- Truck Oil Pan, the LM4 oil pan is a bit shallow for my liking.

Mounting
- VP SBC bellhousing
- Custom fabricated front engine mounts. (I ordered a PAYR plastic engine to help in this effort)
- VP coupler that is used on their LS based engines.

Cooling System
- Johnson Pumps F6B-9 raw water pump. I’m planning on using an aftermarket harmonic balancer to drive it.
- Hardin Marine’s Closed Cooling System. Credit must be given to Scott Price at Hardin. He has answered all my questions quickly and in great detail. He definitely earned my business.

Exhaust
- Marine Power LS1 Manifolds
- Fabricated O2 sensor spacer

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A few good threads about the subject:
http://www.offshoreonly.com/forums/s...-bravo-1s.html
http://www.offshoreonly.com/forums/g...ls-engine.html

100 micron fuel filter before the pump. Mount the pump in the Bildge below the motor. If you have to glass a piece of wood down before you put the motor in to mount the pump. Run a 10 micron or fuel water seperature after the pump (FST Performance are the best). Then run into you fuel rails and put a regulator at the end of the rails that returns to the tank. All that other stuff you have going on there is not needed and a waiste of time and money.

OEM's use fuel coolers because the OEM's and boat manufacturer's don't return fuel back to the tank. But us private guys do.

Oem's use low psi pumps, to a surge tank of sorts, and then to a high pressure pump. But us private guys don't.

Why ? Oe engine manufacturers/suppliers want the engine systems to be as plug and play as possible. Hook up one fuel line from tank, plug in electric harness, connect exhaust. Done !
Warranty issues will less likely involve how things where rigged.

Return line to fuel tank is made simple:
http://www.cpperformance.com/c-500-f...s-returns.aspx
These splice into your fuel fill hose.
http://www.cpperformance.com/images/.../620-76300.jpg

Agree with BB. Also, I used -10 on all lines from tank to pump to fuel rail and mounted the pump as low as possible. This setup has been working great since installing 3 seasons ago.

Thanks Everyone! I love the simple solution.

What fuel pump do you guys recommend? I was looking at the Aeromotive A1000, but I think that will be overkill. I don't plan on making more than 400hp with this motor.

While we're on the subject. Any recommendations for a fuel pressure regulator?

Thanks Again!
Eric

Don't know the p/n, but I use the Holley they recommended for use with the HP efi and my horsepower (not the dominator). As I recall it's coast guard approved as well (double check). I also use the Holley billet filter for the pre filter along with the FST filter/water separator like BB mentions.

As everyone mentioned, go from the tank to the a water sep/ fuel filter. Then to the pump and on to the rails. Add the regulator at the end of the rails (or remote mounted with a hose) so that it only bleeds off excess fuel. You don't want to supply the engine through the regulator. It's can be a big restriction, so just let it bleed odd whatever the engine doesn't want/need. You should run the return back to the tank.

While -10 hose may be a little overkill now, you never know what may happen in the future. Plumb it in 10 now and you will be set for anything you want to do in the future. No sense in doing it twice. For a regulator, it's hard to go wrong with an Aeromotive 13101. For a pump, I would use a Weldon A600. It will support about 700 hp so you have room to grow. They are extremely durable pumps, reasonably priced at around $400, really quite, etc. I MUCH prefer there pumps over Aeromotive pumps. Keep the pump and filter mounted as low and as close to the tank as possible. Ideally, you want them mounted at or below the top of the tank. If that's not possible, keep them as low as you can. The pumps are made to push, not pull fuel.
Eddie

Eddie, Is there a specific reason you don't like Aeromotive's pumps? The Weldon looks like the ticket, but the lack of USCG sticker makes me a bit (probably unnecessarily) nervous.

Thanks Again,
Eric

Aeromotive pumps are hit and miss. Sometimes you get a good one sometimes you don't.

Agree with above

Also, they WAY over rate their pumps. The A1000 won't get within a mile of 1000 hp on an efi engine. The best they will support is about 850-875 hp. The same goes for the Eliminator pump. They may support the power on a carbed engine, but they are sold as EFI pumps.

Weldon actually under rates their pumps. I've used the 600A on almost 800 hp and the 1100A on almost 1300 hp. I wouldn't recommend it, but it will do it. The Weldon pump is quieter and cheaper then the Aeromotive as well. God knows how many of their pumps I have used in the past (several hundred) and I have only had an issue with 1 pump and it was my own fault.

Mercury used their pumps on their larger engines as well, ie. 850, 1075,1200, etc. As far as I'm concerned, they have the best pumps for what we do, hands down.

Let me know if you need help locating a pump.

Also, Jim from Weldon used to be on here quite a bit offering advice. I haven't seen him in a while though. My point is that you typically don't see that type of support from large companies.
Eddie

Jim seems like a stand up guy. Quick responses from the few questions I've asked. It sounds like he is considering getting USCG certification for the 600A next year.

Cool project. I ran a C5 corvette style deadhead setup on my 6.0L in my jet boat. The filter/regulator are built into one unit, and could be mounted near the tank on your application, for easy return of excess fuel.

That setup will EASILY support the 400 hp you're looking for....and beyond.

I prefer the Holley Dominator pumps. For the single reason that you can set the pump up to run in phases. There are actually two pumps in the body so one can be running at idle and the second can kick on at a predetermined RPM or boost level. This will reduce the fuel pump heating the fuel at idle and reduce size of the return needed.

https://www.holley.com/products/fuel.../parts/12-1800

Also, check out Radium. They have a very nice surge tank set up with internal fuel pumps. Really good to make sure you won't get a gulp of air into the fuel system.

https://www.radiumauto.com/Multi-Pum...Tank-P271.aspx

Pleased to meet you Wasted Income. I've read your threads concerning your LS Jet Boat several times.

Precision, Radium tanks are an awesome piece of kit, I just wish it was USCG certified.

I contacted Holley about a USCG pump, but no response. I'm really hoping Weldon can get certification soon for their 600A.

Thanks Again Everyone! I'll start another thread chronicling the build.

I know Holley' pumps are submersible and I belive they are going through USCG certification for the pumps of they haven't already.

With regard to the Radium tanks, I don't know how they couldn't meet USCG requirements. The units are sealed and all AN fittings.

I agree 100%. I'd like the sticker for insurance reasons and not having to worry about a run-in with the coasties.

we have had NO issues with the aeromotive A1000 or the eliminator pumps, with either carb or EFI, maybe just lucky...

I run the Aeromotive A1000 pump as well and that thing primed a huge empty fuel filter/separator in a instant. Not the quietest thing but primes my system up to 60 psi and holds it rock steady.

We use the Areomotive A1000 marine pumps on everything without issues EFI or carbed. We recently dynoed a set of Whippled 610 CID engines that made over 1100 HP and TQ the fuel pressure held steady with no drop, 3 months later they are running strong.

What was the fuel PSI and the BSFC #s of the engine?

The pressure was set at 60 lbs. No BSFC numbers, we ran a -10 feed and -8 return line directly to fuel cell because my dyno only has fuel metering on the inlet side.

60PSI at idle or with boost? If at idle, what was the fuel pressure under boost?

60 PSI set at idle with return fuel regulator vacuum line off. The build was done by a member of OSO that does not frequent the site, if you would like to go over the build with him I can contact him with your info.

OK, well my point is that the A1000 only moves 702lbs per hour of fuel at 60 PSI. So lets use round numbers and say that you were using 10PSI of positive manifold pressure to make the 1100/1100 numbers you posted. If the FPR is referencing manifold vac/boost then they fuel pressure is now 70PSI, and the A1000 can only supply 670 lbs per hour of fuel. Most Whipple motors will run with BSFC numbers in the .650s to the .720s. So using the lean and mean assumption you require 715lbs per hour of output from the fuel pump.

Are you sure the Eliminator pump isn't what was on those motors? They can (barely) support those power numbers, but the A1000 has a very high probability of failure in the aforementioned application.

Not trying to be a smart ass, just illustrating my point of why I have seen these pumps fail above 750HP in EFI forced induction applications.

It would have to be the Eliminator pump. Not trying to argue or get in a pissing match, but I've seen an A1000 not be able to maintain 60 psi through a dyno pull on engines around 900 hp. You can go back and look at the printout and see the pressure steadily falling throughout the entire pull, instead of increasing like it should. The Eliminator pump has a -12 inlet and -10 outlet while the A1000 has a -10 on both ends.

I'm not saying that there is anything wrong with Aeromotive's pumps. Just get the right size pump for the job. I've used them all and prefer a Weldon. Their 1100A is cheaper than the Eliminator, quieter, and supports more power.
Eddie

Percision, I tried to PM you but box is full.

any update on the 5.3?

My wife and I fell in love with a house a few days after I posted this. We ended up moving and the boat project was put on hold. Thankfully I have a nice pole barn to work on the boat now. I can also be on Lake Michigan within 10 minutes of leaving my driveway now. :)

I bought a lot of the Holley parts I needed during their Christmas sale.

This weekend is supposed to be warm...and the wife is gone. I plan on designing the engine mounts and getting them mocked up on the 3D printer at work. I'll start a build thread to start chronicling the build.

This Bosch pump 0 580 254 979
Is capable of 525 hp at 42 psi and is factory fit by Mercruiser.
I have one in my Donzi.

Build thread started: http://www.offshoreonly.com/forums/r...ml#post4414609

also I suggest you change to aftermarket fuel rails w/std fitting for plumbing, can loop 1 end and put the regulator right there for the return to the tank, stock rails/regulator would be a pain...

i know this is like 2 years old BUT ive been doing some digging and it looks like Whipple sets up their fuel system on the 500/525efi kits with no tank return and the pump PULLS threw the factory style fuel/water separator. kinda like the second fuel system set up listed in the first post. im wanting to go that route for space and keeping it all motor mounted, but worried ill eat up pumps. does a aeromotive pump act as a lift pump better then a weldon? or others