mordzy

Active Member

• May 4, 2014

• #1

Hi all,

I'm worried about over pressurising fuel into my carbs with my modern fule pump. I have installed a malpazzi fuel reg but still a little concirned.

Am I right In thinking that if too much fuel is pumped in it should just come back out of the float bowl over flow??? If so I think in ok because the overflow is currently disconnected and had nothing come out.

Ta

 

landowner

Pensioner Pete

Full Member

• May 4, 2014

• #2

mordzy said:

Hi all,

I'm worried about over pressurising fuel into my carbs with my modern fule pump. I have installed a malpazzi fuel reg but still a little concirned.

Am I right In thinking that if too much fuel is pumped in it should just come back out of the float bowl over flow??? If so I think in ok because the overflow is currently disconnected and had nothing come out.

Ta

Click to expand...

Float needle valves will shut fuel off to float bowls when full so shouldn't be able to pressurise (unless pump is very powerful)

 

mordzy

Active Member

• May 5, 2014

• #3

I had an issue with the engine I removed in that after half hour or so the engine oils would smell of petrol. That said, the engine was fecked... That's why it's been swapped. I think it's a 5-8 bar but the fule reg is set to 2 bar. I'm just not getting any fuel overflow that's all..

 

owl

Well-Known Member

• May 5, 2014

• #4

Sounds like you have an injection pump fitted, Pumps for carbs are around 6 - 10 psi and around 30 gals hr.

 

mordzy

Active Member

• May 5, 2014

• #5

Possibly. Here's a picture of the pump, filter and reg.

https://www.dropbox.com/s/q3e0rw5n811b4d0/Photo%2005-05-2014%2009%2005%2042.jpg

Think it might be pressurising again. Oil is starting to smell a bit like petrol. :-(

 

Last edited: May 5, 2014

owl

Well-Known Member

• May 5, 2014

• #6

Can't be sure but that pump looks like an injection pump. The overflow union is primarily a breather and the pipe that goes on it must not have any back pressure (ie piped back to the tank) otherwise the pressure in the float bowl will be increased and your engine will run rich.

 

fanatic

RESPECT IS EARNED, BEATINGS ARE FREE ;-)

Forum Sponsor

• May 5, 2014

• #7

owl said:

Can't be sure but that pump looks like an injection pump. The overflow union is primarily a breather and the pipe that goes on it must not have any back pressure (ie piped back to the tank) otherwise the pressure in the float bowl will be increased and your engine will run rich.

Click to expand...

That looks like a filter king with fuel injection pump, it must be adjusted to 4-6psi for carbs
Malpassi Filter King Fuel Pressure Regulator And Filter - Demon Tweeks

 

mordzy

Active Member

• May 5, 2014

• #8

It is a malpazzi filter king fanatic! I have it set to 2psi. Have disconnected it and just using gravity fed while I sort things. Had the plugs out and they are black. She will only start with choke on.

 

tacr2man

Well-Known Member

• May 5, 2014

• #9

The fuel pump in pic is a facet /bendix pump , as used as standard fit on non intank pump V8 110, which wont need a fuel pressure reg . there is a bleed off orifice in the return pipe from carbs , that raises the line pressure sufficient to feed the carbs requirement.
the pump would be better located down low on chassis say under door, (OE fit) as you will be adding to possibilty of fuel vapourisation , having filter and pump up in top of engine bay , as V8 get very hot in engine bay . HTSH

 

mordzy

Active Member

• May 5, 2014

• #10

Thanks tacr2man. Will relocate before putting on road.

I don't get any fule return from the carbs so couldn't understand if the pressure is too high why there was no return.

Regulator is set at 3psi.

The pump makes a right racket all the time, can you get quiet ones?