044 Return Valve

[GreeceS13]

I will use two 044 fuel pumps.. is it better to leave the return valves or not?

If I leave them I don't know what fittings to use!!

[GeeTR]

The pump outlet is a 1/4 BSP.

Earls, Aeroquip etc etc all make 1/4 BSP -> -6 fittings.

[GreeceS13]

Yes but I will leave the return valves of the pumps?

If I leave it I need banjo fitting with a cap.

But I don't know if I need the return valves... are they usefull?

[green 33]

The valves will usually leak off anyway over a few hour period, and the way i figured it was with the valve there it actually restricts the flow from the pump so i completely drilled mine out, just when starting the car you have to let the pump prime to fill back up the lines

[GTRgeoff]

The non return valves need to be there in case one pump shuts down. If it does then the other will pump straight back to the tank instead of the fuel rail and you could have a wrecked engine on your hands so you have the non-return valves to make sure the fuel only goes to the engine.

[GreeceS13]

The same told me my engineer! But if we have two 044 and one blow and the car run with one 044 it will blow the engine sure!!

If we have one fuel pump like stock cars if it blow, simple the engine stop to work...

What is your opinion?

Also GTRgeoff what do you have to said for the green 33 post?

[GTRgeoff]

It's just Geoff mate. We aren't formal here.

You have to be running a fair amount of power for a single 044 to be running at the limit. The reason for running 2 pumps after a swirl pot fed by a lift pump is to protect your investment in an expensive engine. If you lift your power requirements beyond that of a single pump (in which case there is an argument to run separate fuel lines from each pump) then you must get new pumps that will deliver the power you require.

As for drilling out the non-return valves, they are a restriction above a certain flow rate, but should not cause a problem at the flow rates expected from an 044. If you need more flow, get a larger valve. And yes they will often allow pressure loss in a standing fuel system but every fuel system has that in common. The reason for their existence is to stop the fuel finding the easiest route out, and that will be a pump that isn't running and pressure loss in an engine being pushed hard is almost a guarantee for a meltdown. Sure it may be a little more expensive to do it properly, and not as ghetto or drift cool as drilling them out for extra flow that isn't needed anyway, but it is definitely cheaper than lunching a motor.

[green 33]

mine is mounted in tank, i thought this was for same, but just noticed in first post by greece s13 he said "two pumps" so different circumstances, please disregard my previous post.

[GreeceS13]

I have two 044 with surge tank and one walbro intank. The return from surge tank to fuel tank will have a stock fuel pressure regulator without any vacum so 2.5bar fuel pressure!!!

Geoff can a T04Z runs with one 044? All people here said me no in a topic! I need two! So if one stop work and the other continue to work?? What will be the result? A blow engine!!! Right?

If we have two and one stop work without non-return valves the fuel of the working pump will not go in the engine so we will avoid the lean running.

But we will have a little fuel that will injected in the engine... because the surge tank have 2.5bar fuel pressure..

So I will save my engine with this method? Or I will blow it too?

[Sydneykid]

If you have spent enough money on your engine to truly need 2 x 044's then you should spend the little bit extra and buy a fuel pressure guage. If you have a Power FC, then any leaning out will cause knock and the knock warning light will flash. If you ignore the low fuel pressure and/or the knock warning then nothing will save you.

If you don't have the one way valves, some of the fuel will still go to the engine, just less than what would flow if one pump failed and you had non return valves.

Cheers

Gary

[Adriano]

  Sydneykid said:

If you have spent enough money on your engine to truly need 2 x 044's then you should spend the little bit extra and buy a fuel pressure guage. If you have a Power FC, then any leaning out will cause knock and the knock warning light will flash. If you ignore the low fuel pressure and/or the knock warning then nothing will save you.

If you don't have the one way valves, some of the fuel will still go to the engine, just less than what would flow if one pump failed and you had non return valves.

Cheers

Gary

I certainly wouldnt be running 40 psi fuel pressure in the surge tank, why not just plumb it up like everyone else does, it works fine?

[GreeceS13]

Sidneykid so there is no difference in reliability either with non-return valves or without ?

Either with or not the result is a blow engine ?

I have egt and wideband gauges with warning so I don't think that I need a fuel pressure gauge.

But think also.... if we have non-return valves and one pump don't work we will not understand it! Right?

So more dangerous!!

Maybe when the one pump stop to work to survive my engine... but if the car still works with one pump I will detonate it many times!!

But if you think that with 2.5 fpr at surge tank the one pump will feed the engine properly at low demand for fuel so I will still don't understand the non-work pump.. so if I don't put non-return valves better to don't use fpr to stop the fuel feed totally.

Adriano I like the idea of fuel pressure regulator at the surge because I will be sure that the surge tank is absolutely fuel.

Also if I choose to don't have non-return valves the lines will be empty so long try to start the engine.