Ford Muscle Cars Tech Forum banner

1 - 20 of 25 Posts

·
Premium Member
Joined
·
403 Posts
Discussion Starter #1
hi all, im just pondering the surge tank option for my upcoming 5.0 efi into 68 project, and got to thinking, would it be reasonable to have a surge tank up front

(maybe use something like this - C41794 Jaguar XJS Fuel Sump Tank. Small Header Fuel Tank for XJS | eBay)

(i`m in the uk)

the question being, could i feed the surge tank with the mechanical pump from my 289 (ill be swapping timing cover etc onto the 5.0 im fitting anyway)

cheers,

Mark
 

·
Banned
Joined
·
6,355 Posts
what are you going with , carb or efi ? no need for a surge tank unless you need a high demand fuel flow for a short time
 

·
Registered
Joined
·
10,315 Posts
Sure, that would be fine. I put a surge tank in the front of the wheel well. It was also fed by the stock mechanical pump just as you're thinking. With 3 ports, you would have the high port as main tank return for excess fuel and air, the low port as the outlet, and the 3rd port with a Y-fitting from the mechanical pump and the fuel rail return.
:tup:
David
 

·
Premium Member
Joined
·
403 Posts
Discussion Starter #4 (Edited)
front wheel well! great idea, nice and tidy and keeps all that gas away from the headers too. I`m guessing that means your hi pressure pump is in the well too near the surge tank?

what tank did you use? i guess if its in the wheel well a plastic one would be a good idea...

ive seen this thread here talking about late 80s for truck stock surge tanks - http://www.fordmuscleforums.com/late-model-efi-techboard/508913-efi-conversion.html

id like to get hold of one of those, but theres none on ebay, dont suppose anyone has one? :)

cheers,

Mark
 

·
Premium Member
Joined
·
403 Posts
Discussion Starter #6
OK boy's, please tell me of the Necessity for a fuel surge tank and what exactly it PREVENTS or HELPS when running an EFI engine under the hood.

I'm not savvy to this surge tank necessity, and, it sounds like a bunch of Engineering for naught.

as far as i understand it means that without using a sumped/baffled tank (ie,using a stock carbed car one) then you can run the tank empty if you so desire without starving the high pressure pump, where in a stock tank when the fuel gets low (apparently about 1/4 left), itll slosh away from the pickup cornering etc. and cause pressure drops in the fuel rails which will affect fuel delivery, and also, fuel pumps dont like to pump air. so it kind of acts like the fuel bowls of a carb.

also helps remove air.

and in my opinion it also means the only high pressure lines are right at the front, no running the whole length of the car.. which id prefer.

this is just from what ive been reading.

cheers,

Mark
 

·
Registered
Joined
·
10,315 Posts
Mark is correct about the primary purposes. Even carbed setups often use them on extended powered G-turns as well as off-road vehicles (high-speed and crawlers) as they all have the same fuel pickup, aeration and feed issues. For EFI it's even more important for the reasons he stated, and also that EFI and powerful carb race pumps are far more prone to dry burn-up in a few seconds.

Mark - yes, the pump can be with the surge tank. My first conversion used a small steel fire extinguisher body with brazed barbed fittings. Almost free and very easy. I just band-clamped the EFI pump to the side of the tank with the bottom outlet right into the pump inlet, and out the top with a 90° to run to the engine. See threads here, here, and here for more ideas. For a stock 5.0L, it can be much smaller at just a few ounces.

I recently did another using a spin-on fuel filter assembly. Your idea of plastic isn't weird, as I saw another on a rock-climber made from plastic pipe and two heavy end caps, then drilled and tapped for fittings. With just enough pipe to butt the caps together, the assembly was very stout and strong. I believe it was HDPE pipe.

David
 

·
Registered
Joined
·
10,315 Posts
So that makes it pretty much moot if it's not a race car then right?
Correct, if it is carbed. Still required for plain tanks (without baffles, sump, module or multiple pickups) on any EFI conversion if you want to use more than 1/2 to 2/3 of your fuel before you refill. Maybe down to 1/4 tank if you're a gentle driver in an area with no hills. ;)

David
 

·
Premium Member
Joined
·
34,853 Posts
I get it I get it. Non bafflled tank means sucking air under acceleration (Exactly like a Diaphragm pump does) I get it.

Drive like I do and never worry about it sucking air.... I always keep a moderate 1/2 tank in my car unless on the freeway taking long trips. Surge tank not needed. :) Even if I WAS using EFI....
 

·
Banned
Joined
·
6,355 Posts
Post #2 is accurate only if you are using carbs, but the OP is using EFI, as he stated in post #1.

David
`carbs or efi , makes no difference for fuel demand ... is just that , there is adequate volume or not .

there is a flaw in what he wants to do and what you said you did .
 

·
Premium Member
Joined
·
403 Posts
Discussion Starter #14 (Edited)
sure, i understand that you *can* run EFI without a surge tank/baffeld or sumped tank if you so desire, and people do, but, I understand with is better (otherwise the OE wouldnt have it ;) ) , especially as I often run my tank very low, as my car is a road tripper and stopping for gas all the time isnt something i want to be doing. also, anything that means I dont stress the electric pump is good news for me.

I`m starting to think on maybe making one with an internal pump, something that i can get out of any old common scrappy car for quietness sake, understand externals can be very noisy.. if i go external (easier id imagine) i`ll probably use and old external from an 80s Ford Sierra, or Granada (not sure if you had those in the states) as id imagine pumps from stock motors will be designed to be quiet and durable.


i like the spin on filter idea, two birds one stone etc.

i have access to something like this, would this be too small?
http://www.renaultforums.co.uk/_Use...5/{F2CF6A14-E8D2-4CD8-9113-D0F2E9A3E627}.jpeg

cheers,

Mark
 

·
Banned
Joined
·
6,355 Posts
sure, i understand that you *can* run EFI without a surge tank/baffeld or sumped tank if you so desire, and people do, but, I understand with is better (otherwise the OE wouldnt have it ;) ) , especially as I often run my tank very low, as my car is a road tripper and stopping for gas all the time isnt something i want to be doing. also, anything that means I dont stress the electric pump is good news for me.

I`m starting to think on maybe making one with an internal pump, something that i can get out of any old common scrappy car for quietness sake, understand externals can be very noisy.. if i go external (easier id imagine) i`ll probably use and old external from an 80s Ford Sierra, or Granada (not sure if you had those in the states) as id imagine pumps from stock motors will be designed to be quiet and durable.


i like the spin on filter idea, two birds one stone etc.

i have access to something like this, would this be too small?
http://www.renaultforums.co.uk/_Use...5/{F2CF6A14-E8D2-4CD8-9113-D0F2E9A3E627}.jpeg

cheers,

Mark
stopping for gas(fuel) . you thought a S/tank in the fenderwell is a good idea . think you can a 20 gallon tank in the front f/well ?

plus I can't hear the intank pump on my car .
 

·
Premium Member
Joined
·
403 Posts
Discussion Starter #16 (Edited)
stopping for gas(fuel) . you thought a S/tank in the fenderwell is a good idea . think you can a 20 gallon tank in the front f/well ?

plus I can't hear the intank pump on my car .
dont follow, why would i want a 20 gallon tank in my fenderwell? theres a perfectly good tank at the back ;) which id rather not have to hack up in order to prevent me having to stop for fuel when i have a perfectly good 1/4 tank left.

its a good idea in the sense that it is outside the engine bay, and if a hose goes, its not going to spray on hot headers and set fire to my lovely new engine. the only downside i can seed to that is that its more open to elements.

in tank pump would be nice... but that would mean finding an in tank pump that fit a 68 (unless the fox one does), or buying an expensive custom efi tank.

if i have the pump + surge tank up front, i dont have to redo all my fuel lines, just add a couple of new ones, i get to keep the old carb lines, no messing with the original tank (apart from plumbing in a return, either to original pickup or i was thinking of using a hose barb in the drain plug hole) and no worries about fuel starvation.

cheers,

Mark
 

·
Premium Member
Joined
·
34,853 Posts
Why is it that I am the only guy who understands what the hell I'm saying???


OK new guy, I'll say it in normal human words.

If you're not racing your car.

If you're not LAUNCHING from a dead stop to 60 MPH as fast as humanly possible every time you put the car in gear.

If you're not stepping on and off the gas while on the highway constantly slowing and accelerating, and slowing and accelerating, with only a 1/8th tank of fuel.

If you're not doing ANY of the above things you will likely never harm your fuel pump or fuel system by sucking air.

You do realize that in the car you're using, the stock fuel pickup is only about 1/2" or less from the bottom of the tank? Add that's tantamount to about 1.5 gallons of fuel + - .5 gal. If you're screwey enough to drive the tank that low on each outing, they you just go on with your big bad self and put in this tank that you feel is necessary.

I compare it to the guy that put's a 9" Ford rear in his inline 6 powered car... Or the guy that puts Slicks on the back of his 200 HP 3800 lb station wagon.

But that's just me thinking here. Nothing essentially helpful about things I say sometimes...
 

·
Registered
Joined
·
1,786 Posts
OH I understand FE, just aint tossing my hat in the ring.... ;) But on another note, are wee talking about an NHRA S/S 200hp "factored" wagon, or just a run of the mill 200hp wagon? :confused:
 

·
Banned
Joined
·
6,355 Posts
Why is it that I am the only guy who understands what the hell I'm saying???


OK new guy, I'll say it in normal human words.

If you're not racing your car.

If you're not LAUNCHING from a dead stop to 60 MPH as fast as humanly possible every time you put the car in gear.

If you're not stepping on and off the gas while on the highway constantly slowing and accelerating, and slowing and accelerating, with only a 1/8th tank of fuel.

If you're not doing ANY of the above things you will likely never harm your fuel pump or fuel system by sucking air.

You do realize that in the car you're using, the stock fuel pickup is only about 1/2" or less from the bottom of the tank? Add that's tantamount to about 1.5 gallons of fuel + - .5 gal. If you're screwey enough to drive the tank that low on each outing, they you just go on with your big bad self and put in this tank that you feel is necessary.

I compare it to the guy that put's a 9" Ford rear in his inline 6 powered car... Or the guy that puts Slicks on the back of his 200 HP 3800 lb station wagon.

But that's just me thinking here. Nothing essentially helpful about things I say sometimes...
FE , your on the right track . OP states one thing , expose fuel pick up on high G turn , then doesnt want frequent stops for fuel . doesnt make sense to me . now if a real race car , track only , then it would .
this is not the 50'/60's or even the 70's . modern fuel supply and delivery systems can handle any type of build with correct pumps ,tanls and plumbing for a given use
 

·
Registered
Joined
·
10,315 Posts
... If you're not doing ANY of the above things you will likely never harm your fuel pump or fuel system by sucking air. ...
That's simply not true, FE. While pump damage is not the primary concern, if an EFI system sucks air, the pressure goes to zero and the engine quits. This is no different than if your carb jets sucked air, but injectors have no bowl of fuel. If your carb had no bowl to separate air or accumulate fuel, and the jets were fed directly from the pump - you'd have the exact same issue. This is like adding a bowl of fuel just for the injectors to always have straight fuel at full pressure, all the time, under any conditions.

A fuel tank with 2" of gas will slosh it all to one end even in a gentle turn, and the engine quits. What's the point of carrying 20 gallons if you can only use 10-15 gallons of it? But it's not a big deal, you just have to account for it, with a sump, or module, or baffles, or accumulator (surge tank), or multi-pickups, or any other method that prevents the high-pressure pump from sucking air. No biggie, and all EFI and mechanical injection cars have some provision for this built-in. But, this wasn't originally an EFI car, so it needs to be added. That's all.

David

PS: The surge tank/accumulator/header tank system we are talking about has been used in millions of cars, trucks and vans for over 50 years. Millions. It has nothing to do with horsepower or driving like a maniac.
 
1 - 20 of 25 Posts
Top