Fuel Delivery

[RetroMk2]

Hi guys.

I am now planning my fuelling requirements and wanted to know what other people have done in the past in relation to carb to EFI conversions (in particular later model engines - such as the Mazda/Ford BP1800, CA, SR etc etc).

The things i'd like to know (and please be as technical as you can) are in relation to what you have used/done re:

• Fuel lines;
• Return lines;
• Fuel pumps;
• Surge tanks; and
• anything else required.

Estimated power goal will initiall be per mazda factory (approx 70 - 80 kwatw), but anticipating a jump to 140 - 160 kwatw afterwards - so a system to suit this goal.

Any help much appreciated.

Cheers, Dave.

[jewels]

dave
as far as fuel lines are concerned you only need to add another as the return to the tank. the size the same as original will be fine

fuel pump, probably the best and cheapest and readily available would be to use a VL turbo pump which are external this is the main EFI pump or hi pressure

you will also need what sometimes is called a push pump or low pressure pump. a facet (barrel type) or carter electric pump will be fine and these are in most good car accessory shop.

you will need to buy a surge tank these are made by many local and asian manufacturers. this usually is mounted in the boot of the car. sonfiguration can vary as in where in inlets and outlets are but they will all do the same job
look at these as being the actually bottom of the tank fuel and where the efi pump will draw the fuel from.

another place you can use to return from the engine fuel back to the tank is the fuel filler neck or anywhere really

the push pump will take fuel from the actually fuel tank and keep this surge tank full at all times when full there will be an outlet to return extra fuel back to the tank

here is a pic of one of our surge tanks this is probably a little bigger than you need there are 4 feeds on on the bottom (cant be seen in this pic)

there are many types or surge tanks ready made even on ebay up for grabs

[RetroMk2]

Thanks for that

So what of the original pump on the side of the tank - what would that be used for?

Does anyone have any schematics as to the order of placement for these items/flow diagrams etc?

Like I said - any help muchly appreciated (might as well ask the people who have done it in the past, instead of get crooked and half-% *% *% *% *ed responses from other forums around the place).

Dave

[jewels]

im not sure dave what you mean by pump on the side of the tank? are you talking about the push pump?

this pump a carter or facet is only used to take fuel FROM the fuel tank TO the surge tank

Its only job is to keep the surge tank full so the efi hi pressure pump has fuel available all the time

yes i have a diagram that may help i will get to scanning it and upload later for you

[RetroMk2]

im not sure dave what you mean by pump on the side of the tank? are you talking about the push pump?

I mean the original pump on the side of the fuel tank (attached - sorry for the crappy pic...).

yes i have a diagram that may help i will get to scanning it and upload later for you

Champion!

[jewels]

retro that pic is of the fuel outlet

a hose is just connected to that which then goes to the low pressure or push pump then from there goes into a surge tank like what i pic i posted from there the efi or hi pressure pumps feeds the engine

[RetroMk2]

Thanks for that. It is all becoming a little clearer now.

[jewels]

here are the piccys i promised

as you can see there are 2 ways of doing it (the return) in the first to images

10.2 and 10.3

[RetroMk2]

Awesome - thanks for that.

Do you know if I would come up against any problems going an external swirl pot as opposed to an internal one when it comes time to get it engineered?

As this progresses, i'll be sure to write up a DIY.

Dave.

[jewels]

dave you may still be a little confused

all swirl or surge tanks are external
the only thing that sometimes can be 'internal' is the EFI fuel pump and this does not apply to your situation
you will have external low pressure and hi pressure fuel pumps as well as the surger tank

your exsisting fuel tank will be basically unchanged

and no you will not any problems on engineering as long as the outlets or fittings can not be hit by anything loose in the boot of the car

[RetroMk2]

dave you may still be a little confused

all swirl or surge tanks are external

Oh, ok. I was under the imperssion by the last diagram - there is mention that the swirl pot may be build into the tank floor ("A swirl pot can be built into the base of a steep petrol tank, removing the need for external swirl pots...").

External would be the way to go anyway i think.

Does the area need to be well ventilated? I anticipate hiding this as the boot is boxed in.

Cheers, Dave.

[jewels]

to build into your existing tank is quiet a job and its not generally done unless the car in some cases had efi to begin with

no ventilation is required coz the complete system is sealed so no fumes escape into that area

your normal fuel tank vent is still used

[RetroMk2]

Sorted - thanks.

Time to make a shopping list and slot it in with the normal fortnightly food shopping (she might just surprise me

Will let you know how i go.

Dave.

[Dr Danger]

Hmmm. My engineer did not like the surge tank in the boot and wanted it either underneath the car or not at all. I just deleted it for the final inspection and made sure the tank was full of fuel. Consult the person engineering it to save you alot of time and messing around. A short fat one underneath - in theory - is just as good as a tall thin one in the boot.

[geoff]

mmmm. this is very
interesting,makes me
wonder how hard this
really is hi hi hi hi. :}

[Dr Danger]

I'm just telling the nice people what they really don't want to hear BEFORE they hear it. So they can brace themselves...

[RetroMk2]

I'm just telling the nice people what they really don't want to hear BEFORE they hear it. So they can brace themselves...

I call it a challenge

[geoff]

fair call. al
this is my last
posting on this
topic (i just have no time
for this at the moment)

[Gordon of Oz]

I have a 1700 cross flow set up for fuel injection in a Mk 1 240. I used 4 throttle bodies and injectors off a Kawasaki motor bike and a Haltech F9 computer. I made up a short inlet manifold and air box and trunked the inlet to the pax side of the engine bay where it collects air that by passes the radiator. It works really well and there are photos on this website somewhere.
Gordon of Oz

[Gordon of Oz]

I do not know about the junior member bit, I turn 69 tomorrow !!
Gordon of Oz