8 replies to this topic

[Jimbotime]

Hi Guys,

Im now on the way to starting up my mini rebuild for the first time but Im wondering if you guys could give me some help.Im currently putting in the copper fuel line and its all in and then I was going to put the return pipe in to go back to the tank but Ive been speaking to a guy whos into minis and he said that my mini doesnt do that theres just a pipe that connects to the carb and it drains on the floor?but i thought it did as my tank has the nozzle at the top of the tank?Its a 1980 mini 1000 now a 1275 though and it has a hif 44 carb.Hopefully you guys can clear this up for me.

Cheers James

[Leykor]

Hi Jimbotime

The top nozzel/hole is where the overflow pipe is fitted. This pipe allows any extra fuel to drain out. The pipe is normally routed straight down and open to the ground.

I know it seems strange but t\this small hole aids the fuel in leaving the tank. Think of an oil tin or juice box, People normally make two holes(one on the front and one at the back) to make pouring easier.

This top hole allows atmospheric pressure to be applied to the fuel and acts as a runnoff.

Hope this helps.

[Jimbotime]

Brilliant thanks for the help so Im guessing there isnt much fuel wasted then by doing it this way?Cheers

[mgb1978]

Just to clarify, the pipe coming from the top of the Tank is a vent pipe. This is to allow air into the tank as the fuel level drops.
There is a fuel overflow on the hif carb which is normally routed down by the clutch cover.
There is no need for a return pipe as the fuel pump does not deliver enough pressure to require one.
Not sure where the vent pipe from the tank goes....on the newer minis it connects to ther charcoal canister behind the front passenger wing.

[Jimbotime]

Cheers for that!

Ive added a facet fuel pump but also added a fuel regulator in the engine bay im guessing that shouldnt make any difference?

[mgb1978]

Yes , once you use the regulator to keep the fuel pressure around the same as the mechanical pump you will be fine.
The hif carb doesn't have a facility for a fuel return pipe.
If the hif gets too much fuel pressure it will blow the petrol past the float and you will be left with a load of petrol on the ground from the overflow.
The mechanical pump puts out between 3 to 7 psi so set your regulator around 5/6 psi and it should be ok

[Jimbotime]

Brilliant cheers for the help!!

[Cerberus]

Yes , once you use the regulator to keep the fuel pressure around the same as the mechanical pump you will be fine.
The hif carb doesn't have a facility for a fuel return pipe.
If the hif gets too much fuel pressure it will blow the petrol past the float and you will be left with a load of petrol on the ground from the overflow.
The mechanical pump puts out between 3 to 7 psi so set your regulator around 5/6 psi and it should be ok

I'm pretty sure mine has got a fuel return line from the carb to the tank.

I've got a 93 italian job, with 1275 with HIF44 carb. Fuel tank has two lines. One at the bottom, and one at the top.
I've not traced where the second one goes to yet.

Also, there is a load of gubbins on the top of my tank, which looks like a fuel filter, and possibly some sort of pressure relief valve.
However, as I'm writing this, I'm pretty sure the outlet pipe, just comes straight out the tank and down through the boot, and that the fuel filter isn't on the outlet pipe.

I'm going to have to take some pictures of my tank and post up a new topic as something seems weird,

[jayare]

On the Italian Job along with all carb'd cars after about '91/'92ish the fuel tank has the feed and vent the same as any other non-injection Mini, the only difference being a one-way valve on the vent pipe (to prevent fuel loss in the event of a rollover). The vent pipe is connected to the charcoal canister under the LH front wing. Earlier Minis had the vent pipe just poked out of a hole in the boot floor. The charcoal canister was fitted so the petrol fumes didn't just get vented to atmosphere,

JR