The_Pipefather

iTrader: (5)

We are investigating the influence of fuel flow vs fuel specific gravity for different concentrations of ethanol in gasoline. A model of the whole thing has been built using CFD software and is giving good results, but we want to validate the model using a real experiment. Hence the decision to build a test rig.

Any ideas for a quick-n-dirty setup? I was thinking of a miata fuel rail with 1.6 stock injectors (since I already have them) mounted on a test bench. Graduated 500 ml cylinders to catch the test fluid. some sort of simple circuit to trigger the injectors for a set amount of time, say 1 minute.

The part I dont have any ideas for are what hardware to use for fuel tank and a pump. I'd think an inline pump is ideal but they're hard to find. Any ideas for the tank and pump?

Loki047

iTrader: (6)

Why not buy a flow bench? And then sell it to me when your done?

Or clean my injectors

The_Pipefather

iTrader: (5)

Cause it costs too much compared to what we want to do. This is not a personal project, it is for course credit and funds are non-existent.

Joe Perez

iTrader: (8)

If you're just comparing static flow rates, then the setup you describe sounds fine.

In actual practice, injector flow rate measurements must take injector lag time into effect. In other words, between the time you apply power and the time fuel actually starts flowing, there is a delay. Likewise, when you remove power, some fuel will continue to flow for a moment while the injector closes.

The_Pipefather

iTrader: (5)

Well that doesnt matter to us since the only variable is ethanol content and rail pressure.

Joe Perez

iTrader: (8)

What about using a Miata (or whatever other car you might have lying around) as the fuel tank and pump? Seriously- either disconnect or tee the fuel supply and return lines, and jumper the fuel pump relay on continuously. Inexpensive.

If you really want a dedicated test setup, try begging around the forum to see if anyone has upgraded their old FM or Bell system and no longer requires the Pierburg pump.

Braineack

iTrader: (62)

12' of hose will move that rail about 6' away from the car

ignition switch is an easy trigger, just need another length of wire....

KGP

iTrader: (9)

there is an SAE paper on this experiment...

The_Pipefather

iTrader: (5)

please post the paper number or reference. Right now we are using SAE J1832 which is recommended practice for fuel injector testing, as a guideline.

Doing all this in the car is out of the question. The test has to be done under standard test condition of 21 deg. C which is kinda tough to replicate in March in Detroit .

Anyone want to donate a Pierburg pump to the cause?

LOOINEY

You could just run a 5gal. fuel can with inline pump and return line back to the can and a simple toggle switch on and off... Kind of the idea of a engine dyno's fuel supply?.. just my .02

KGP

iTrader: (9)

I will have to dig it up... J1832 should be a good guide.
Please pardon me as I am not really sure what you are trying to accomplish even after reading your post. (or maybe I should say "why")

from what I recall, the specific gravity, although a factor, was not as important as the stoiciometric fuel ratio of the mixtures as far as how much fuel flow you would need. I have some info on how to determine the flow rate you would need based on this info. The info on determining the injector size when going to E85 from gas can be found here: http://www.injector-rehab.com/kbse/e85injectorsize.htm

Ill try to remember to try to find that paper number for you when I get in the shop tomorrow.

The_Pipefather

iTrader: (5)

Thanks...

as to why we're doing this its got more to do with the flow through the injector itself rather than injector sizing. Can't say any more that although I'd like to, sorry Damn NDA kicks in right about here.

This is what I was considering. However the switch needs to be much more precise than that. We were thinking of some kind of simple timer-based switch.