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dpuma8

Does the fuel pump have to be mounted lower than the fuel tank?

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dpuma8    0

I am trying to fit the 1QT BC Bronco's Surge Tank into my 1975 Z along with a Carter fuel pump.  I have both fuel pumps in the spare tire well and have a thick cover that screws over the wheel well.  The surge tank is mounted in the old fuel pump location in the fuel pump bracket. 

 

I am assuming I made a mistake now but just in case, I wanted to ask.  Can my Carter pump be located higher than my gas tank?  If I ditched the surge tank, would there be any issue of going Tank>filter>Carter Pump>Walbro?

 

Current setup is Tank > Filter > up to the Carter Pump > Surge Tank > up to the Walbro Pump.

 

Attached is a picture of a format I kind of copied from this site.  It is from the 5thgenluder build

post-7714-0-72136900-1408989121_thumb.jpg

Edited by dpuma8

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NewZed    56

Carter says that you have up to 24 inches from the bottom of the tank.  I'm kind of surprised.  http://carterfuelsystems.com/fuelpumps/_pdfs/training/InTank_Elec_FP_Inst.pdf

 

On your installation - it's the vapor in a closed space that will cause the explosion.  That looks like the typical boat bilge area accident waiting to happen.  The shape of the spare wheel well will channel the blast up in to the hatch glass though, which will act as a pressure relief valve for the cabin.  Looks scary.

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NewZed    56

Here's a couple of threads showing engine bay mounting and mounting by the fuel tank.  If you sealed the top of the wheel well from the cabin and put a couple of large vents in the sides of it, you'd probably be fine.  It's just the high pressure fittings in the cabin that look dangerous.

 

I'm sure that there are people running things like that but I wouldn't.  One leaky fitting and there's puddle of fuel in the cabin with you.  Even a tiny leak will stink up the cabin.

 

http://forums.hybridz.org/topic/110485-bcbroncos-surge-tank-install-and-use/  by the fuel tank

 

http://forums.hybridz.org/topic/115077-280z-fuel-tank-vs-surge-tank-for-efirb-swap/  Post #9, engine bay

 

http://themidnightmechanic.wordpress.com/page/2/  engine bay

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danigrrlz    0

Just wondering but if you cut the wheel well out and put a major trap door over the wheel well, wouldn't it kind of be the same in a way as moving the protective floor up a bit to make room but in essence the pump is still outside?

 

About the vapors being in the car, the vapor tank already is in the car on the right behind some plastic molding. So what's the difference?

 

The other thing I was wondering was in my maxima, underneath the back seat was a tiny hatch door and the was the pump and all the fittings. If there was a leak underneath that trap door or vapor buildup, wouldn't that be really dangerous?

 

Just shooting some thoughts out!

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Six_Shooter    13

I don't know why you guys complicate fuel delivery so much.

 

I run a single Walbro pump (currently, planning on going to a dual pump system), fed from the drain plug in the bottom of my 240Z tank. The fuel pump is mounted about where the original electric pump would be in a 240Z (Just inboard of the right rear wheel, and several inches above the tank bottom). I've been doing so for 6 years without issue. The only time I notice that anything might be a little bit different is when fuel level is below 1/8 of a tank, which just about any fuel system set-up will show signs of warm fuel or lack of fuel pick up at that point.

 

If you really want a surge type system, cut the fuel tank open and have a surge tank or baffle installed. It takes no extra space, doesn't really effect fuel capacity, and will keep the fuel pump(s) submerged in fuel, and there's no fuel in the cabin. This is also on my list of plans, to move from the external pump to an internal, but I haven't found a good reason to do it yet, with my current system working fine.

Edited by Six_Shooter

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NewZed    56

I don't know why you guys complicate fuel delivery so much.

You mean the three of us; me, dpuma8, and danigirlz?  Or everybody on Hybridz?  Just wondering if you're above just us three, or everyone.

 

Why are you going to two pumps if one has been working so great?  

 

And the only difference between your ingenuity and stock is the point of fuel pickup?  An exposed fuel pickup doesn't seem like an improvement over the protected stock point.  Looks like you've gone backward.  And then another idea, untried.  I don't see any true value at all in your post besides an attempt to pump up your self-image. 

Edited by NewZed

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Tony D    143

Most pumps don't work well in suction service, so they default to a flooded inlet. There should be plenty of room for a carter or bendix style plunger pump under the car (there was for mine, and the surge tank)....

 

Some people move the surge tank and flooded high pressure pump up front to the engine bay if you think room is a problem.

 

I've always used plunger/solenoid pumps to prime the surge tank, they allow some lift, reliably --- the stock EFI pump won't work if you put it up front, even with a full tank flooding the inlet, sucking all that way it will fail to supply enough fuel for even an 80RWHP setup! Put it in that stock position in the same car, and it's flowing enough for 300 RWHP+.

 

The  stock 240 tank has issues with the pickup getting uncovered at anything less than 1/4 tank (and can uncover at 1/2 tank under proper conditions!) One 'go lean' under boost on an EFI system where it just drops suddenly...and you understand what the Surge Tank does for you.

 

I would NOT put fuel pumps in the tire well unless you made a proper firewall. There is plenty of room to put stuff under the car, on the stock mounting points for the electric pump, and on the floor like a 280Z (there is two pumps, in back, using stock locations.... the Surge Tank can be mounted near the plunger/solenoid pump...)

 

I'd start putting components  up front before I ever put them inside the car. The Bronco Surge Tank can mount with a stock Bendix Style pump on the stock electric pump mount, feeding the EFI pump up under the bin like on a 75 280Z.... if nothing else, there is your fuel system, safe, external, and non-immolating!

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Six_Shooter    13

You mean the three of us; me, dpuma8, and danigirlz?  Or everybody on Hybridz?  Just wondering if you're above just us three, or everyone.

 

Why are you going to two pumps if one has been working so great?  

 

And the only difference between your ingenuity and stock is the point of fuel pickup?  An exposed fuel pickup doesn't seem like an improvement over the protected stock point.  Looks like you've gone backward.  And then another idea, untried.  I don't see any true value at all in your post besides an attempt to pump up your self-image. 

 

 

*sigh*

 

Two pumps for more flow to provide more fuel when I turn up the boost, in a parallel system, not because there's anything wrong with what I'm running now, it supports the power level I'm at just fine and has worked great for 6 years, as I already said. I'd go one larger pump, but that means more cash outlay, I have at least two Walbro pumps in my possession, so I'll use what I have, and then if I have to I'll buy a single pump, if I don't like the dual pump system.

 

My pick up is no more exposed than many other systems I see on many cars. I have never had any issues, with ANYTHING coming in contact with it, so your attempt at making my pick up seem less than it is or a problem is nullified right there. BTW I drive my car DAILY, so if an issue was to ever come up it would have come up by now.

 

The other idea, untried? Really? Really? You think no one has done that? Try all OEM vehicles are like that, I've also personally done it on a friend's S30, and it is working great for him. I know of many other vehicles that have also been retrofitted in similar ways. There are drop in fuel pump modules that provide a similar result in the aftermarket, Aeromotive is one brand that provides such a module, if you feel like looking proven systems that work.

 

The lesser used system of having a sump tank inside the tank has also been proven, where you take this external system and move it inside the tank. At that point most people opt for the basic sump, that holds fuel and is fed by fuel movement rather than a second redundant fuel pump.

 

I'm trying to provide insight into ways that I as well as other have provided fuel to their engines, being baffled how over engineered these systems are that people are using simply because one or a few people think that you need to over-complicate it because it was said long ago that one or a few people might have had fuel starvation issues under certain circumstances.

 

You just might want to look at other options that will not only save time, but money and keep serviceability easier, before trying to beat your chest. ;) Many times simple is better. I've learned the hard way over many years that simple has always proven more reliable and in many cases works better. It's also easier to troubleshoot.

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Nigel    5

I run a single Walbro pump (currently, planning on going to a dual pump system), fed from the drain plug in the bottom of my 240Z tank. The fuel pump is mounted about where the original electric pump would be in a 240Z (Just inboard of the right rear wheel, and several inches above the tank bottom). I've been doing so for 6 years without issue. 

 

Have you tried this on a road course yet?

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Tony D    143

Starve for fuel in a stock 240Z with 1/2 a tank once, and you realize the stock pump pickup is inadequate. If you want to use that pickup point for simplicity, and don't want to redesign the fuel tank, or install a pickup that is exposed on the bottom of the tank so you're forevermore constrained to tarmac-only events or driving only on paved roads (and my drain plug having been close to sheared off more than once attests to that!) then a simple prepump, surge tank, and HP pump is easy. OEM's do it...see "Ford Bronco". 

 

I drive on dirt roads, regularly, and sometimes the road isn't nice. Putting a pickup in the drain plug on my 260? That's a recipe for being stranded somewhere a ways from anything, nearby nothing! Curiously, the Kenya East African Safari Cars used a simple Surge Tank and three pumps for feeding the Carbs (triples), they did not take a tap from the bottom of the tank.

 

I'd pass on that unless it's a strict Drag Car.

Edited by Tony D

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dpuma8    0

Darn.  Got my car started with Megasquirt but this in trunk method didn't work for me.  The Carter fuel pump would get very hot while my Walbro pump was pretty loud.  I read the FAQ about directly connecting the Walbro and Carter fuel pumps together but then the poster mentions a problem 14 months later.  I want to move everything out of the spare tire well and direct connect the two pumps together near the gas tank if recommended.  I also want to get rid of my surge tank since from what I hear, my 75 Z doesn't need one (is this true?).

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JSM    15
Posted (edited)

Is this the Bronco part your referring to use as a surge tank?

 

https://bcbroncos.com/collections/fuel-pumps-filters/products/accumulator-filter-1-qt-long-version-for-early-bronco

 

Is this basically a modified Fram HPK2 oil adapter? Curious if this came on an early Bronco what was the part called?

Edited by JSM

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