roastin240

iTrader: (13)

Anyone know of a 24 Volt fuel pump that works with diesel fuel?

I need something that can flow a minimum of 5 gallons/hour at 80 psi. This is for a small 1.25 liter turbo diesel application thats going into an offroad 2 seater ATV.

The pump will operate between 40 and 80 psig, feeding the high pressure cam driven fuel pump. Maximum fuel delivery at high rpm/load is 5 gph. Anything more delivered will just be bypassed back to the tank. Thanks in advance.

stevieturbo

Does it even need to be high pressure, seeing as it's just feeding the mechanical pump ?

Protec make a lot of pumps, maybe try them ?

https://protecfuelpumps.com/

roastin240

iTrader: (13)

Yes this is where we are operating at. Currently we supply 65psig constantly at all times to the mechanical pump. I will be evaluating it at lower pressures after the new calibration is developed on the engine dyno in our facility. However, previously we were having rail pressure drop issues at high load/rpm which was resolved with increased lift pump pressure. I believe the discharge coefficient of the mechanical pump is low enough that the only way to get the volumetric flow required for the power is a higher base pressure into it.

roastin240

iTrader: (13)

Protec is 1 of 20+ manufacturers that have already been called. They do not make one. Name a company, I bet I have called them already.

stevieturbo

And why the necessity for 24v ?

Surely there are plenty of 12v pumps you could use, and just run a voltage reducer ?

Even odd for such a small vehicle to run 24v ?

roastin240

iTrader: (13)

No I cannot. This is a unique application at work. This is our prototype engine we have developed from scratch, been durability testing and calibrating for the last couple years. It is going into an offroad 2 seater ATV. They are requesting a 24V system. We already confirmed 24V engine management system availability from our supplier (Nira), and we have sourced a 24V waterpump. Cannot seem to be able to track down a diesel lift pump that can supply more than 30psig and operate on 24V source.

roastin240

iTrader: (13)

Anyways...if anyone has a source, let me know. We have tried everyone under the sun. I will be testing at high load and rpm later this week and stepping down fuel pressure from the lift pump to verify our findings from previous testing. I need to verify 100% again that this is the case prior to having a custom pump built at a big $$$ pricepoint

stevieturbo

What do the big diesel truck racers use ? Or would they all be fully mechanical ?

And is it out of the question to just use a 12v pump...albeit at 24v ? At least for testing anyway.

Or in a more bizarre way, locate 2 small 12v pumps and wire them in series ?

roastin240

iTrader: (13)

Most of the 24V diesel pumps are marine applications.

We do not wish to use a power inverter to drop it from 24V to 12V.

And the last suggestion is electrically incorrect. Your thinking of wiring 2 BATTERIES in series to produce 24V. If this were the case, then you could wire off of 1 of the batteries to supply the 12V source. However, the customer does not wish to run 2 batteries. they are running a single 24V battery. No we cannot change their requirements. This is a 3 million dollar prototype engine. If an electric fuel pump that flows 75 HP worth of diesel costs 3 grand to finish the package, that is a drop in the bucket. But finding a COTS available unit is economically more feasible as well as eliminates alot of the risk involved with development and durability testing of a new pump/motor assembly.

stevieturbo

No, I'm saying to wire 2 12v pumps in series from 24v so in operation both pumps will only see 12v.

http://www.4qd.co.uk/docs/motors-in-...-and-parallel/

roastin240

iTrader: (13)

Oh I misunderstood you. Well that would technically "work" but pretty much any COTS pump will flow WAY more than the engine requirements and will be returning most of it to the tank anyways. With 2 pumps, this might not even work with the integral fuel pressure regulator/bypass in the mechanically driven high pressure pump. Only so much can be bypassed. Plus this is another piece of hardware, double the current draw, additional leak paths, additional weight and required bracketry...doesnt make sense and would not be acceptable in this arena. Going the power inverter route would be down selected before that route. Could also go real ghetto and dump voltage through a big resistor...but that would never fly. We need a 24V pump.

stevieturbo

I guess the other, cheaper and perhaps best option ?

No doubt the car has an ecu, surely it would be very easy and cheap to run a PWM controller for the pump, or even onboard from the ecu and run a regular 12v pump in that manner.

A 50% PWM cycle on a 24v system would effectively be the same as as running the pump at 12v ? It shouldnt affect pump longevity or performance ?
And as BAP's do, you'd have a lot of headroom for some extra flow.

it's not as if fuel pump or motor controllers are uncommon these days

roastin240

iTrader: (13)

I have been TRYING to convince our company owner and my supervisor to let me persue this path! I absolutely love the idea. I guarantee the PCM has PWM control. If it cant spit out a high enough frequency then you use a simple frequency multiplier that ramps it up an order of magnitude to result in less pump losses (electrical power than ultimately turns into heat rejection). It would be very very nice as well because we dont have to recirculate 90% of the pumps flow all the time. I love the idea. I need to put together some info as well as check the manual for the Nira PCM and see what the output options are. Also I need to find a variable speed pump that is compatible with Diesel and can put out 60psi at 50% duty cycle.

stevieturbo

I wasnt suggesting closed loop control, but absolutely that would be another option too.
And again any 12v pump will have lots of headroom on a 24v system

You dont need a variable speed pump, pretty much any regular DC motor will be very happy when PWM'd or via an H Bridge thingy which makes any motor variable speed.

roastin240

iTrader: (13)

I hear what your saying but when I said variable control I wasnt referring to a 3-phase AC control like used in the supercharged LS9 factory fuel system. I am only talking about variable speed based on DC control using PWM. Most control systems have the ability to control PWM output frequency up to 100-200 Hz. At this switching frequency, you produce a lot of heat in the electrical components downstream of the controller, including the pump. One way to resolve it is a frequency multiplier that ramps it up an order of magnitude (for example - 100Hz to 1000Hz).

I was updated today that one of our electrical engineers are sizing and selecting an appropriate power inverter that has integrated high frequency PWM control. So all is well now and we will be running a 12V pump with speed control...no external relays/contacters needed. Power in, power out to pump. Thanks for your feedback Stevie

stevieturbo

Does the LS9 use a 3 phase pump ?

There are 12v Brushless pumps you could use, again Protec make these. But they probably flow about 20x what you need

And I agree, 100-200Hz is low, a few thousand would be better.

I actually just ordered a Crydom SSR the other day that is rated for 1000Hz and I'm going to try it on my own car.
Although there are plenby of cheap DC motor controllers on ebay etc that will PWM at a few thousand Hz.

Or others have used OEM fuel pump controllers of fan controllers to the same effect. I believe a Range Rover of some sort uses a PWM based variable pump controller that can be bought very cheap second hand.
Or others in the US have been using a GM fan controller module

Forcefed86

iTrader: (4)

Looked at 24v Aircraft hydraulic/brake pumps and fuel pumps?

This claims 35gph at 18psi... I'm sure it can be modified for more pressure and less flow.

http://www.ebay.com/itm/Fuel-Pump-24...1TDPMP&vxp=mtr

Hyd pumps

http://www.ebay.com/itm/Eaton-Hydrau...8AAOSwm8VUvtOE

http://www.ebay.com/itm/Raymond-Dock...kAAOSw03lY7j0p


Or a 24v to 12v step down box?

roastin240

iTrader: (13)

We are not in the business of modifying off the shelf components for single 1 off use like you and I and alot of others here do on our cars. This is a very expensive prototype engine that took years to develop, redesign and test, etc etc. Only the best is used. But yes we have selected a power inverter ("step down box" - 24V to 12V) to drive a traditional COTS 12V diesel fuel pump.

The hydraulic pump idea is a good one though. I didnt think to look into that market, thanks for the suggestion! I would have to be sure the seals in the pump are functional with high sulfur content diesel, as well as other low lubricity heavy fuels like JP-8, Jet-Fuel, JP-5 etc. Would it work for 3 years before failure? maybe...but in this application it would not be accepted unless it was 100% guaranteed to work with excellent chemical compatibility between the fuel and all materials it comes into contact with. trust me, if it were my own vehicle, it wouldnt be a hard decision for me lol.

Krom

Ford and GM uses pw fuel pumps, you can use one of their modules.

http://www.rockauto.com/en/catalog/c...e+module,14756


Hell this will prob work as is:

http://fuelab.com/products/performan...ine_fuel_pump/

stevieturbo

Except the Fuelab will also flow about 20x what is needed lol and would anyone seriously trust one for OEM reliability ? ( not to mention unit price )