fuel pump flow/ pressure and injector sizing?

[SuperV8]

I've been thinking more about my 3.5 to 4.6 supercharged conversion and i've got to the fuel system.

I currently have a Bosch 0 580 464 038 external fuel pump. I have had a google but can't find fuel flow/ pressure figures for it?

Then thought about my injectors and required fuel flow. Im aiming for 400BHP.

my curreny injector flow is 248cc@3bar
I've worked out to get 400BHP i'd need 350cc@3bar injectors using a BSFC of 0.60 or 320cc using a BSFC of 0.55. Does anyone know/ guess what the BSFC of my engine would be using a centrifugal supercharger?

If the BSFC would be 0.55 I could run my current injectors at 75PSI to get 320cc (if the fuel pump would support this? What would you think a safe (ish) max pressure to run at?

I have a feeling I might need new pump/ injectors? just trying to do the math??

Any help or opinion much appriciated.

Tom.

[stevieturbo]

some injectors...especially old ones dont like running at increased pressures...so beware.

As for the fuel pump...test it and see what it flows. Its the only way to be sure.
Failing that, a 909 is a good pump. Not quite on par with an 044, but pretty damn close.

or a Walbro GSS392 inline.

Cheapest set of 8 new injectors would be the Bosch 42lb greens. They'll give you plenty of fuel with no worries.

[bigaldart]

For a centrifugal supercharger I would target BSFC in the 0.65 -0.70 range to be safe. Injectors don't like a duty cycle above 80% and even with a pressure rise I think you would be struggling. Any fuel system err on the side of caution, supercharged I take the experts figures and from experience would add between 25-50%. All figures I have ever seen underestimate how much fuel it takes to turn the blower, especially at low rpm with load.


Alan

[SuperV8]

Thanks for the advice,

Yes definitely going with larger injectors/ pump.

using 0.65BSFC and 80% come out at 426-cc injectors which is nearly the 42lb that stevie turbo suggested. I'll get on e-bay.

Also need a fuel pump which will flow over 200L/h. The Walbro 255 looks like it would fit the bill.

I'm adding the megasquirt II card which apparently gives much better resolution for controlling large injectors. Don't know if 42's are large? they sound large to me, probably not thought!

[stevieturbo]

42's are not large.

A Bosch 909 or Walbro GSS392 are two decent inline pumps available at sensible prices.

[Coops]

i run the 044 bosch pump and green 42lb injectors as stevie recomended on my old 3.9 and had no probs at all. (was mappable ecu so i could set the req fuel)
now running the pump and injectors on my 4.6

[SuperV8]

I have remember I have a brand new Pierburg fuel pump in my garrage

7.50051.60.0

It flows 240L/h at 2bar which is plenty. The only thing is it is NOT suitable for use with methanol/ ethanol? It is approved for use with biodiesel.

Does anyone know if that would mean gasoline as well?

Cheers,
Tom

[SuperV8]

An update on my fueling.

I've ordered a Bosch 044 pump. I looked into various options. I work at Delphi Lockheed and we actually sell various fuel pumps, unfortunatly none are quite big enough I ordered the 044 through a friend and at a very good price so i'd rather that than buying a pump slightly cheaper BUT on the limit of its flow.

I've also been looking into injectors. Decided I need 400cc injectors which will give plenty of head room. The Bosch 42lb is the obvious choice, but I got reading about design III bosch injectors EV6's. These are multi orifis valves compared to the pintle type of the earlier bosch injectors. This is supposed to give better atomisation over a greater range of fuel pressures, which will be an advantage as i'll be supercharging my engine so the fuel pressure will rise whatever boost I run above the base fuel pressure.

My problem was these EV6 injectors have lots of different spray angles and types (single cone or twin cone) Google Bosch EV6 and there are some interesting PDFs. I've figured (guesses & assumed) that the spray type/ angle/ width will depend on how far the injector is from the valve. Too wide and or too far away and it will coat the intake walls, too narrow and or too close and it won't mix properly with the incoming air?

In the end i've gone for a Bosch EV6 (pn 0280 155 968) It's a green injector used on Volvo V70R's. Supposed to be 415cc/min at 3bar, 20 deg spray width and twin cone. It is the same length as the 4.6 rover injector 72mm (odd) and a high impedence which suits mega squirt. Also uses EV1 (mini timer) type connector so will just plug in. Some EV6's use CSCAR connectors.

Oh and they were also a very good price on the Bay, ordered them today from the states, already on the way, 3-5 days delivery... Amazing IF it works

Your thoughts welcome,
Any one used EV6 injectors on the rover V8? Good/ bad?

Tom.