Dual Bosch 040 Fuel Pumps

EvoLuTioN

no-JZ Your Mom!
Mar 10, 2006
508
0
16
Bed
Hey, I have a shop thats my sponsor and they want me to slap on their custom surge tank with a built-in fuel pump. They told me it was a Bosch 040 in a keg like design for a swirl effect. Basically fuel from the tank goes in from the bottom, which then gets picked up by the in-tank Bosch 040 pump and goes to the fuel rail. On the return it goes back to the bottom, while all this is happening, it's creating a swirl effect causing the fuel to move to the top where all the "hot" fuel is, returning to the main tank. I think I wrote it properly.

It's going to be a DUAL in-tank bosch 040

Bosch 040 pump is 235 litres per hour and supports 520 bhp at 73.5 PSI # 0 580 254 040

I'm thinking it runs 20 lph less than the walbros, and if I go for say 900rwhp (SP74mm Turbo, some big injectors when the time comes, -8 dual feed, etc) would this setup be enough? I know dual walbros are good for 900-100, so I'm wondering if this would be in the same ball game and how "good" this concept is.

surgetanknb9.jpg
 
Last edited:

bgrieger

New Member
Mar 30, 2005
206
0
0
52
Toronto
Paraphrasing Pulp Fiction: the 040 is the one that has BMF written on the side...the 040 does not have the peak no load flow of a walboro (how they are rated for advertising), but makes up for it under pressure. With increasing fuel pressure, the walboro doesn't hold a candle to this unit. A quick internet search will yield the flow curves. They are pretty dramatically better at high pressure! Since you're sponsored, the cost of an 040 won't be a problem either, though it ain't cheap!

The surge concept is nothing new. This "hot vs cold" seperation concept is a new spin on it, and in the confines of a tin can, all the fuel is going to be for all intents and purposes the same temperature given how long it is there. Sure, heat rises, and placing the inlet far away and above the outlet will help ensure the fuel in the tank the longest and hottest leaves so in theory, the hottest fuel is going out, but given the amount of time it spends in the can and the swirling of the fuel it will quickly reach a stable temperature in there and the difference is going to be nearest to zero.

The setup in the drawing is about the same as any surge tank setup I've seen, but that return to tank placement on or near the top is just so it purges the air from it, not because of any heat issue. Given the fuel will swirl and mix around, I can't really believe the concept they are trying to promote, but I may be wrong. The pump being inside it is a little different than most, which should give it the most cooling compared to an external arrangement, and that should extend the life of the pump.
 

annoyingrob

Boosted member
Jul 5, 2006
2,304
0
0
Calgary, Alberta, Canada
Why go with dual 040? Why not just go with an 044 (~340lph).

And what bgrieger said, even though it doesn't appear to flow as much as a walbro, walbros are garbage under pressure, which is why you see people needing so many of them for higher horsepower. A single 040 at higher pressures (say 65psi) will outflow a walbro by quite a bit.

Because they flow so well at higher pressures, fuel line restrictions become much less of an issue. dual -8 would be overkill. a single -8 would be plenty.

FWIW, I have a stock pump feeding an 044 all through stock (-6) fuel lines. I have no flow problems whatsoever.
 

flubyux2

Madd Tyte JDM yo ®
Apr 2, 2005
1,019
0
0
43
st. pete, fl
www.myspace.com
why wouldnt the delivery line to the fuel rail be at the bottom?

i would want the line going to the rail as far away from any possible air contamination as possible. i think the fuel line return should come in the top, next to the fuel tank return. the delivery from the tank should be in the bottom, below the delivery to the rail. i think the rail deliver should be on the other side though, for laminar flow. i mean, i think ive seen cans of this design before but wasnt sure where each nipple went.
 

EvoLuTioN

no-JZ Your Mom!
Mar 10, 2006
508
0
16
Bed
flubyux2 said:
why wouldnt the delivery line to the fuel rail be at the bottom?

i would want the line going to the rail as far away from any possible air contamination as possible. i think the fuel line return should come in the top, next to the fuel tank return. the delivery from the tank should be in the bottom, below the delivery to the rail. i think the rail deliver should be on the other side though, for laminar flow. i mean, i think ive seen cans of this design before but wasnt sure where each nipple went.

the fuel pump is built inside of the tank, so the fittings would be from the top.