Diesel instrumentation

[oldbeaver]

It would be great if you can share with all of us where we can get "Zemco like" flow meters.

Thank you in advance.

Oldbeaver.

Originally Posted by consaka

Actually vibration is not a good way to describe it. The transducer really does pick up very small pulses of the steel line expanding when the injection even occurs. You are talking about alot of pressure here and it happens pretty fast. If it was vibration then what vibration? because the whole engine has tons of various harmonics and vibrations.
With these older engines the easiest way is to use two zemco like flow meteres and subtract the return line pulse from the supply pulses, take the leftover pulses and feed those into the mpguino. DCB could, I am sure modify the program to count pulses and associate fuel use to each pulse similar to the way we do now. Shoot with my peak and hold gasser injectors thats basically all the mpguino is doing anyway.

[consaka]

Originally Posted by dcb

The premise is that the old timey diesel pumps are positive displacement. If the length of the injection event can be determined as well as the rpm (both from the same sensor) then it should be possible to get a relative consumption figure of the fuel that was just squirted into the cylinder. That would be the simplest in terms of installation anyway, but you might have to go through a few tanks to get it dialed in (business as usual for most fuel consumption gizmos)

hmmm what about fuel leakoff? This is literally fuel that leaks past injection pistons at the pump and at the injectors. This is the wear factor and will change with time. I guess you could recalibrate once a year or something. Also what about differences in pump design? I am only really familiar with the stanadyne pumps that came on early GM vehicles. Basically the piston rolls up a ramp. At idle it barely touches the ramp where at full throttle it is allowed to hit the whole ramp. Timing is controlled by turning the ring like housing that has the ramps in it. I could post a picture of the parts that actually do the injection events. I have a stanadyne pump from an GM 6.2 liter diesel. These pumps were used a lot and eventually modified to be computer controlled for the later 6.5 engines.

[diesel_john]

i was just toying with a prototype injection signal measuring sensor yesterday, you might need to attenuate the signal a bit with a couple Meg pot so you don't over range your A to D.
Parts: 2 used GM knock sensors, one 1/4" FPT x 1/4" FPT pipe coupling.
Tools: a drill bit the size of my injection line, a 1/4" pipe tap, hack saw or dremel.
Procedure: drill a hole in the center of the coupling, thread the coupling deeper on both ends until the knock sensors will reach in to the hole, cut one side of the coupling out until it will fit over the injection line.
Place coupling on a straight section of the injector line.
Hand tighten the knock sensors until they clamp on the injection. Wire the sensors in parallel. Attenuate signal as needed. see pic
i tapped on the bolt with a pencil and it made the analog bar on my Fluke jump, i don't think signal strength is going to be a problem.
Oh, BTW, there are two of these knock sensors threaded into the bottom of the water jacket on most injected 350 chevy's. make provisions to handle the antifreeze when you unscrew them.

[diesel_john]

Originally Posted by oldbeaver

It would be great if you can share with all of us where we can get "Zemco like" flow meters.

Thank you in advance.

Oldbeaver.

Beav, i have seen them on ebay type sites. i try to make stuff. but if you don't mind buying, you can get modern flow meters for a $100 or less. An old Zemco will probably need a new ball and light, so can't go to high on price.
A lot of talk about it in this thread
http://ecomodder.com/forum/showthrea...-new-post.html

[dcb]

Dang John, you make it look easy

I'm not %100 on why two, or how to wire them up though. In series I presume, for a larger signal?

Oh, and obligatory drawing of what came to mind when I saw the pic Harder to manufacture but should be able to clamp down harder w/it.




P.S. we should probably keep the diesel stuff in this thread. Hate to see you guys having to type everything in twice.

[diesel_john]

two opposed because they cancel horizontal "vibration" but retain the expansive signals. wire parallel for this effect. i noted there were two in the store bought example. GM because there is an endless supply. don't squash the line, hand tight. difficult to wire in series anyway, base is one wire and connector is a single pin. tools to harvest sensors 7/8" 6 pt. deep socket (they are very tight), wire cutter and a bucket.

[consaka]

Originally Posted by diesel_john

i was just toying with a prototype injection signal measuring sensor yesterday, you might need to attenuate the signal a bit with a couple Meg pot so you don't over range your A to D.
Parts: 2 used GM knock sensors, one 1/4" FPT x 1/4" FPT pipe coupling.
Tools: a drill bit the size of my injection line, a 1/4" pipe tap, hack saw or dremel.
Procedure: drill a hole in the center of the coupling, thread the coupling deeper on both ends until the knock sensors will reach in to the hole, cut one side of the coupling out until it will fit over the injection line.
Place coupling on a straight section of the injector line.
Hand tighten the knock sensors until they clamp on the injection. Wire the sensors in parallel. Attenuate signal as needed. see pic
i tapped on the bolt with a pencil and it made the analog bar on my Fluke jump, i don't think signal strength is going to be a problem.
Oh, BTW, there are two of these knock sensors threaded into the bottom of the water jacket on most injected 350 chevy's. make provisions to handle the antifreeze when you unscrew them.

Ok this is just ingenius. I love it.
questions and suggestions. Id love to see a scope reading off of this.. part and full throttle.. pretty please?
I suggest a junkyard for those knock sensors or just get a couple new ones from the parts house.
I seriously would drop all my current projects to try this except its a pain in the butt getting to my injector lines in my VAN. I have a custom doghouse and laptop holder all setup right in the way.

[consaka]

Originally Posted by oldbeaver

It would be great if you can share with all of us where we can get "Zemco like" flow meters.

Thank you in advance.

Oldbeaver.

Im sorry but you cant get them anymore. They are out of business. You can sometimes find old ones on ebay but not very often. I have fixed a few old ones so even if they dont work and you find one keep it. They are very simple. Most dont work well on larger engines without slight modifications, due to the small orifice inside.
Of course you still need a circuit board design to drive it and produce a signal the mpguino can read.
DCB or one of the others may be able to post a schematic that would be able to render a signal suitable for the mpguino.

[consaka]

Originally Posted by dcb

Dang John, you make it look easy

I'm not %100 on why two, or how to wire them up though. In series I presume, for a larger signal?

Oh, and obligatory drawing of what came to mind when I saw the pic Harder to manufacture but should be able to clamp down harder w/it.




P.S. we should probably keep the diesel stuff in this thread. Hate to see you guys having to type everything in twice.

If you did it this way dcb you should probably back up the injector line or it might get bent. perhaps weld in a flat piece of steel to back it up or better yet weld in something the shape of the injector line for full support on the back side. Then thread one sensor on over the top. What do you think diesel John?

[dcb]

Originally Posted by consaka

DCB or one of the others may be able to post a schematic that would be able to render a signal suitable for the mpguino.

Find a flowmeter first, then we can discuss