Fuel Pump Flow Data... Lph Vs Psi

[GTRNUR]

Im chasing data for the old VL turbo 070 fuel pump to find out what it can flow at 70-75 PSI. As I understand it, most of these bosh pumps really take a flow dive after about 68-70psi but I need actual flow data.

The picture below is the sort of thing I am after. Flow vs PSI. Still searching but no 070/vl data yet other than...

0 580 464 070........... 130............ (3 Bar) (43psi)

Cheers,

Ian

Edited May 16, 2010 by GTRNUR

[KiwiRS4T]

Regardless of specs wouldn't its old age indicate a new pump being a good idea?

[GTRNUR]

Its not for any particular project that I need the data.

I am investigating someone's engine blow up, and have found out their base pressure was peaking around 75psi. At this pressure, the flow rates potentially drop off significantly. If I know what the pump flow rates were I can calculate the flow at the injector and work out if the problem was actually the pump or if it was something else.

[KiwiRS4T]

OK well you have probably found the same web pages as this one:

http://www.lucasinjection.com/bosch_and_lucas_fuel_pumps.htm

which shows four flow charts for Bosch pumps and in each case the pressure drops off sharply after the rated pressure so the 070 pump rated 130L/hr at 3 bar would pretty much not be flowing anything much by 5 bar.

[GTRNUR]

Yep saw that one. Good graphs at the bottom of that page too, but no 070 data. Thanks for searching though.

[Harey]

I am investigating someone's engine blow up, and have found out their base pressure was peaking around 75psi.

I dont think you mean 75psi of base fuel pressure, because if you were running 15psi of boost, your fuel pressure would be 90psi!

Do you mean 75psi of total fuel pressure?

This can be a major issue with increasing the fuel pressure to get more out of a size of injectors.

[GTRNUR]

The engine in question was naturally aspirated and the base pressure with the regulator vacuum hose was set to 60psi at idle. With the hose disconected/WOT the pressure went to ~72-75psi.

The engine was only running 4 x 300cc injectors which was adequite for the engines power requirements, but if the pressure was too high (into the area that flow takes a dive), pump flow might have not been enough to keep fuel up to the engine. The engine in queston had the piston detach from the rod. Then the rod went about making holes in the case, breaking the camshaft and then everything else was damaged or destroyed due to valve train interference and loss of oil pressure. It all goes bad very quickly above 7000 rpm.

[Harey]

The engine in question was naturally aspirated and the base pressure with the regulator vacuum hose was set to 60psi at idle. With the hose disconected/WOT the pressure went to ~72-75psi.

The engine was only running 4 x 300cc injectors which was adequite for the engines power requirements, but if the pressure was too high (into the area that flow takes a dive), pump flow might have not been enough to keep fuel up to the engine. The engine in queston had the piston detach from the rod. Then the rod went about making holes in the case, breaking the camshaft and then everything else was damaged or destroyed due to valve train interference and loss of oil pressure. It all goes bad very quickly above 7000 rpm.

Apologies, I thought being in the forced induction section it wouldnt be N/A

Yeah I see your logic, it is a possible cause.

[Adriano]

If the rod broke the cam, im hoping it wasnt your VW motor. Its an interesting idea though, raising the pressure to get more fuel through the injectors, which kills the pump flow to the point it cant feed the injectors. However remember if the pump couldnt keep up, the rail pressure goes down and the flow goes up.

[GTRNUR]

Sorry for the confusion posting in forced induction... I figured it would be the right place because it was using a "VL turbo" pump.

Yes it was a VW engine but not mine.

The thing with the tune of the engine was that it wasnt even close to running near max duty cycle, so there was no need to run the fuel pressure high. It would have been better for everything (fuel temps, electrical system current drain etc) if it had been 43psi. Whats left of the engine now really is just carnage. There isnt much left to try and diagnose the cause of the failure. $10k worth of engine destroyed.

[daisu]

If the rod broke the cam, im hoping it wasnt your VW motor. Its an interesting idea though, raising the pressure to get more fuel through the injectors, which kills the pump flow to the point it cant feed the injectors. However remember if the pump couldnt keep up, the rail pressure goes down and the flow goes up.

Then as soon as the flow goes up the pressure would increase.... going around in circles. It would reach an equilibrium somewhere below the required pressure.

The increased pressure may have overloaded the pump causing internal damage, which would then result in lower flow rates.

Set the pump up on a bench with an adjustable FPR set at the pumps rated pressure and check the flow rate. If it's below the quoted flow rate then that proves the pump was failing.

If the pump is within spec at it's rated pressure, bump the FPR up to 72psi (or whatever the setup was on the failed engine). Measure the flow rate again and do the calcs.

[T04GTR]

from my days at mercedes on the old cis and cis-e injection, the test pressure was around 85psi base pressure. these were all bosch roller cell pumps. some single some ran 2 smaller vlturbo sized pumps in series.

i would of thought that the bosch pumps were designed to run these sorts of pressures

[T04GTR]

looks like my 044's will work with my 5 bar reg. with 2 bar boost

[rob82]

looks like my 044's will work with my 5 bar reg. with 2 bar boost

Hope you have good injectors as most are only rated up to 8bar. Also most new ev6-14 injectors specify 4bar operating pressure.

As for investigating the failure I would be checking the flow rate of the pump you used on the vehicle. How pumps work in operation compare to actal flow data can be quite different.

[Harey]

looks like my 044's will work with my 5 bar reg. with 2 bar boost

I dont see why high fuel pressures is getting you excited. The general principle I thought was to run as close to 3-4 bar of base fuel pressure to keep things reliable and keep fuel temps down. I thought really high fuel pressures (5bar+) were just for people that couldnt afford the proper sized injectors.