Injection pump and injectors test bench - PeachParts Mercedes-Benz Forum

subetealabici · #1 11-19-2010, 02:49 AM

I been fiddling with the car in different areas trying to tune it up on the best possible way, and to make it run on wvo without major modifications.
So I finally bough and injection pump to test on a bench the injectors and different fuels.
The idea in this thread is to have as many possible input about the pump tuning and function and test all in the bench to see the result before putting the pump in the car.
And to share some of the projects around the oil filtration, I made a centrifuge filter with some pinter parts and some other bits and pieces that I found around work.
So far the car is running great, it is getting harder to start with the oil but the first 2 hours of testing the pump and rebuilding the injectors pay for the price of the pump at the pick and pull.

layback40 · #2 11-19-2010, 03:17 AM

What car is it you have?
Why not just convert the WVO to bio diesel?
Its not the injection that is the main problem, its the combustion characteristics of the triglyceride that you are using.
have a read of this

http://www.ncat.org/special/oilseeds_innovations4.php

This was with fresh oil. Not stuff that had been boiled for an extended period.

subetealabici · #3 11-19-2010, 11:34 AM

Hi

It is a 240D.
I may try to convert the wvo to biodiesel in a future, but the idea is to have the car running just on straight oil.
I also think that heating the oil before enters the IP has little or no difference in the weather here in Portland Or, once the oil enters the engine it will go to any temperature that the IP or the engine is at due to the fact that most the part and pipes are cold during the start.
The idea with the test bench is to set up the injectors to spray the oil at room temperature of 40F at the lowest, I think that is the path to have a clean combustion avoid carbon build up and other problems.

Thanks for the reply the reading on the ncat.org was interesting but there was no modification on the fuel delivery other than preheating the oil

Biodiesel300TD · #4 11-19-2010, 12:33 PM

Layback, I'll say the same thing I've said before, that study and all the studies I've ever seen are not on a properly built 2 tanks systems with lots of heat, and I think this biases the results. All the studies are single tank systems with little or no heat. That study is a single tanks conversion, with one band heater and a coolant heater. On start up they are injecting cold VO. Cold VO starts = DEATH for the engine. My VO system has a coolant heated fuel tank, coolant heated fuel lines, coolant heated fuel filter and two electric heaters. Far more heat than they'll get out of a band fuel filter heater and coolant heater. They saw problems starting in two months. My system has transported me 50k miles since I installed it in Sept. of 2007. My car will fire up no problem.

Now back to the OP. subetealabici, I think your barking up a tree that a lot of people have already tried, and many have failed. Elsbett has been playing around with single tank VO conversions for a long time. Their systems do modify the injection of the fuel. But no matter how much you tweak the IP or injectors, cold VO will never burn like diesel or biodiesel, even at 100F. So unless you come up with a way to preheat ALL the fuel, especially the fuel that is going to be immediatly injected on a cold start, you're going to have problems. Cold VO is where the biggest problems arise when running VO. It causes more gelling and sticking.
Also, your stock fuel system doesn't heat fuel very well. It may come up a little but not nearly enough to make VO burn as complete as diesel. There is a reason that Lovecraft no longer has a store in Portland, and I'm not really sure that their LA shop it open either. And even if it did come up to the 160*F range that it's best to burn VO at, that is only going to happen one the engine is hot. So you've got 5-15minutes of unheated VO being burned.

How are you turning your Injection pump on the bench?

Diesel911 · #5 11-19-2010, 12:40 PM

Injector Pop/Nozzle Tester yes.

So called test stand no.
In order to get any idea what the Fuel Injection Pump is doing you have to run it long enough on the Test Stand to get it nice and hot. After that in order to measure the Fuel Quanitiy with any accuracy you need to have a Flow Meter for each Injector or some sort of switching valve so one Flow Meter can be used on each Injector.

Or the older way after clearing the Air out of the system you hit a button on the Test Stand and it channeled the Injected Fuel into Graduates. After X amount of strokes of the Fuel Injection Pump it cut the Fuel (actually Calibration Oil) off from going into the Graduates and you read the measurements of each Graduate (one Graduate per Fuel Injection Pump Element).

There is more to it than that but the above is the bare minimum.

Diesel911 · #6 11-19-2010, 01:02 PM

Quote:

Originally Posted by subetealabici

Hi

It is a 240D.
I may try to convert the wvo to biodiesel in a future, but the idea is to have the car running just on straight oil.
I also think that heating the oil before enters the IP has little or no difference in the weather here in Portland Or, once the oil enters the engine it will go to any temperature that the IP or the engine is at due to the fact that most the part and pipes are cold during the start.
The idea with the test bench is to set up the injectors to spray the oil at room temperature of 40F at the lowest, I think that is the path to have a clean combustion avoid carbon build up and other problems.

Thanks for the reply the reading on the ncat.org was interesting but there was no modification on the fuel delivery other than preheating the oil

I think the issues are about the stuff that will not burn under any circumstances, the stuff that burns but turns into something bad when it burns, acid, and the non-consistent variety of stuff that is in WVO.

Processing VO/WVO into Biodiesel attempts to solve the above issues.

moon161 · #7 11-19-2010, 01:18 PM

Good reading on the topic.

SVO

Biodiesel basics & beyond

Rafi · #8 11-19-2010, 01:23 PM

Wow, that is some setup, how do you turn the IP ? by hand or do you have a motor attached ?

Biodiesel300TD · #9 11-19-2010, 02:11 PM

Quote:

Originally Posted by Rafi

Wow, that is some setup, how do you turn the IP ? by hand or do you have a motor attached ?

He's got to have a motor of some type. You'd never be able to turn it fast enough by hand to pump any fuel.

moon161 · #10 11-19-2010, 02:43 PM

IDK, it's a displacement pump. Leakage can't be too significant @ low RPM- if you couldn't pop an injector at low RPM, your car would never start. Cranking rev's are about 200 RPM, the IP and cam run at 1/2 crankshaft rev's. 100 RPM, don't have to be Jack Lalane to manage that.

Olivier · #11 11-19-2010, 02:51 PM

I had to search Jack lalane and found an old man in blue spandex

Olivier · #12 11-19-2010, 02:53 PM

To subetealabici
any chance to get more info on the centrifuge? You mentionned vrious parts from a printer.
Cheers.
Olivier

subetealabici · #13 11-19-2010, 07:40 PM

Hi

I'm just starting with the pump set up, I use a drill with a socket to turn the pump, in any case the pump still works if you turn it by hand, I think since is a reciprocant or displacement pump and it is independent from the turning speed.

I think there is a bunch of nasty stuff in the WVO, for sure, and it burns decently for a car with and old worn engine, the main problem is to start the car it runs perfect once the engine starts.

I also think that heating the oil may be a good idea but no matter how much heat the oil has, the is no way to transport that heat to the nozzle at the starting moment, so any preheating system for the oil in a 40F weather is a loss of energy, maybe a block heather would be somehow helpful, but the point is to save resources.

I remember seeing the injectors test benches wen I was a child, and the idea is to run the pump with the injectors for a period of time and have the injectors spraying into graduate cans, now I just put some bottles, and see the amount of oil coming out, of course that may change depending on the temperature/viscosity of the fuel, but I'm sure I will get a very decent approach with the cans.
I'm very intrigued by all the levers and mechanism involve in the control of the pump, and I think that there is many things that can be tweak in a simple mechanical way, from more power on a uphill situation, to lees fuel going on a flat area.
This is not a high precision test is more a simple approach to all those things that diesel car owners would like to see like the spray pattern from and actual IP/injector set up, different nozzles sprays, etc.
I work at and electronic recycling place and the centrifuge is made with half a transfer drum from a phaser and a random 3500rpm motor, that is very small, and you need to start by hand, and some valves and buckets, it is filtering 5 gallons in an hour without the hassle of cleaning up clogs filters heating the oil or pumping it, all the dirt gets trap by gravity on the drum walls and the "clean" oil overflows from the top, the feeding goes to the bottom.
I'm collecting parts for the next filter that is going to be made with a smaller drum and some old hard drive spindle motor that spins up to 7500 or 10K RPM there are some SCSI motors that go up to 15K RPM but there are to small.

C Sean Watts · #14 11-20-2010, 10:24 PM

Unless I missed something, it looks like the main filter has been bypassed and some mixture of chocolate milk and mud puddle are going into the IP.

I'm not discounting the effort but neither the IP nor injectors will last very long like that.

subetealabici · #15 12-09-2010, 12:19 AM

Hi

It was a kind of cold to work on the shed, I was also busy with other stuff, so I got a manometer and check the opening pressure on the injectors, I tried to get them as close as possible swapping the washers, I also lap some of the parts, they are all around 115 bar.
I was also looking at the return valves function, even wen all the injectors open at about the same pressure, they don't start spraying at the same point wen the pump is spin with the drill, I try swapping the injectors around and got the same result, It was only wen I change the return valves pressure that they all start at the same time.
I run it for some time and they drop about the same amount of fuel.
I also put the calibrated injectors in the car and runs very good, idle is very smooth, It has more power to.
The pump that I was using on the bench has some problem in the lift pump and doesn't run very good with the wvo.
I will try to swap the pumps over the weekend maybe.
WVO, or cocoa, is a cheap source of fuel for the car, it has other uses to,.