Ok guys this might be a little out of left field...

So my thought is that while someday I would like to buy a real pulse adapter, I don't have 200 bones laying around.

Why can't we put our heads together and think up a way to build a pressure-switch that lights up a timing light, just like commercially available clip-on adapters do?

It seems to me we could build a new hose, and somewhere in the hose "T" in a pressure-activated switch that sends an electrical signal to a light. It CAN'T be that hard. Can it?

Pressure would be set at 1800 PSI and boom, timing setup.

You don't even need hard lines, grease lines at Harbor Frieght are practically free and pressure rated up to 3200psi. How to make the lines can be figured out easy enough, I'm interested more in the sending-unit aspect.

Thoughts?!?!

Thanks guys!
-Joshua

 

things to know.
1) maximum burst pressure. im assuming you plan on leaving the fitting in there permanantly. whats the most pressure the ip/injector can handle?
2) strength engeneering of the part so that handeling 2k-3k of pressure doesnt blow the sensor out of the line. if you dont get a prebuilt one.
not sure about the plezeo electric sensors and how hard it would be to get/make one reliable enough.

3) plezeo electric like the ferrit uses changes vibrations in to voltage. you have to have a high sampling rate just a guess but 8khz sampling rate to make sure you can pick up exacly when the pulse is. 2-4x the maximum rate needed to read. I just looked real quick in the pic controllers adn most of the current ones should work fine i think (rusty with the stats)

4) inductive electronics. you need to know how much juce @ what voltage will set off the timing light

 

1. I have no idea what the burst pressure of an injector are, but I'm sure that it's more than the seals inside the IP can handle. Injectors are designed to pop off at 1800psi for N/A but I've no idea what would happen if the injector somehow seized. But unless I was under the hook looking at it I am certain we'd all be ok. Just swap in a usable injector.

2. My thought was actually just to change the line whenever I needed to time it, the #1 injector is an easy line to take off. (But either way of course I would be using parts rated for somewhere around 3Kpsi)

3. I think making a pezioelectric device would be ideal, but not practical.

4. I hadn't planned on using induction to fire the light. It's just a zenon bulb that I figured would fire based on the electrical signal of the pressure sensor. I don't know much about zenon bulbs though. Dunno if it needs more that 12v to fire.

Thanks for the thoughts and ideas!

-Joshua

 

Subscribing.

I recently gave in and ordered the Ferret unit due to time constraints, but I can't stop telling myself I should have cooked up a way to do it in my head.

I had imagined using a piezo sensor for the injector line and a magnetic pick-up at the crank, both connected to an Arduino, which could calculate the degrees and report them to an add-on LCD screen. Finding a suitable piezo is the constraint... but this idea of a tee and pressure sensor is a better alternate.

You could fit the tee in where the 7.3 injector sensor is on #1 line. Any ideas where to get a presssure sensor in that high a range?

 

I don't want to squash you guy's hopes, but there is a reason why these units are pricey. By the time you find a suitable sensor, and figure out how to read it and interpret the signal, you'll have spent everything you've saved, and probably more.

Also, swapping the line out to test is a bad idea. Diesel injection lines are a precise length, all of them being the same length. If you change the length, you change the timing in the one cylinder relative to the others, which is not good for the engine. And just because a line is rated for a certain pressure doesn't mean it will work here. If the line expands under pressure, it may absorb some or all of the injection pulse and cause the injector to not fire, or fire erratically.

I think you'd have better luck trying to figure out a way to make a luminosity probe, although a piezo system might not be that hard to engineer, I doubt its worth the time and money.

 

the ferrit sensor is 120-140 whole unit 170-200.

you are likely to spend about 10$ on a couple pic controllers. simple lcd could be as low as 20. if buying every thing new probably 50 for the main unit. sensors no idea.

lume probe would be a pita to make but doable. not sure what quarts "glass" would cost and the cost to have a custom casing made. smaller machining so it could be quite a pain. high temp high spead/sensitivity photo sensor.

bear was just thinking of dupilicating the ferrit didnt think about replacing thetiming lite lol.

 

I wouldn't make a lumy probe... that's definitely beyond the scale of DIY cost-wise.

You can make the damper pickup out of common junk, the Arduino board is 20$, a nice LCD is 10$ but you can just plug into a PC and avoid that part. The tough one is the pressure sensor, that type is between 100-150$.

If you could find one used or sacrifice it off something else, you could be in business for less than 50$, and that with that method you can read timing directly and not need the timing light either.

 

I was poking around today and found a post in the Mercadies bends? diesel forms where some one mentioned a different brand who owns the pattent that the ferrit and others use.. unit is 450 w light and mag pickup. the sensors from then are about 70$ reading the sensors are most likely not that bad to do since its just a on off signal. finding a chip thats high enough resolution to do that would be a bit of a pain but not to bad. i could see the parts being 100$ total adding the timing light part might not be to horible to do and simple lcd/timing retard calculater being easily doable. 20-40 in parts to have a all in 1 unit that would be smart enough to calculate it all...

 

Nice find, Kendrick. Link?

I'm more of a mechanical guy, though between you and NorthernDiesel it seems like we have some electrical-leaning thought going...

Seems like something that really could work. I like what ND said about using a laptop to read the thing. I wonder how to hook it up though.

And I have a differet question-- when I go to the DOT smog tester, they just hook two leads up to my battery and somehow get my RPM's. How does that work?

Oh and just because it's sorta cool-- tonight I built a flexible injector line using the aformentioned grease line from Harbor Freight!
I had a line break on me the other day and so I cut about 3" from the good end and welded that onto one end of the grease line, then sacrificed a good line for science and welded another 3" end on the other side of the grease line.
Hooked it up in the truck and it worked great! Problems came when I moved it... the welding is too hot for a grease line and melted the jacket under the crimp-on fittings. But it worked until I disturbed the already-tormented crimp-on part.
The best part is that my welds stayed dry! I have no formal training and am self-taught at welding so that's huge for me.

-Joshua

 

Sorry guys I am going to resurrect from the dead. Maybe there is some renewed interest here. I know I am interested. Perhaps we can start with the Ferret Piezo element. What does anybody know about it?

 

Even though the Ferret pulse adapter is no longer available there are plenty of other options out there. I'm surprised that Josh Bear was able to fabricate an injector line that worked.

 

Here are some adaptors that might help?

https://tinytach.com/timing-equipment

Charlie

 

A few months ago, I contemplated making a replacement Ferret adapter and selling it. I sourced replacement piezo clamps (you can buy them online in bulk) and the electronics to convert the signal to a pulse is trivial. But with all the work, it wasn't economically viable for a business option. I'd have to sell them at $400 just to make the profit worth while, and I doubt anyone would pay that much for the device.

 

I am talking about making something for around $40. I think it's possible we just need to convert a pulse something a regular timing gun can read. We need a 50 Cent piezo element (clamped onto the number one injection line to ramp voltage up high enough that it can trigger the timing gun. We should be able to pull this off with a standard automotive coil. Now we need to piezo element to trigger the coil.

Before anybody gets to far ahead with all the timing advance stuff lets just assume we will make a new mark down by the pulley where 8.5 BTDC should be and just adjust timing until we get the line out to there instead of trying to build circuitry to bring the timing mark back to zero. Does that make sense?

 

Here's a good video on timing your IP:


Here's one of the most reasonably priced timing adapters available. Occasionally they're available on Amazon too.

https://www.ebay.com/itm/Gunson-77089-Diesel-Adaptor-For-Timing-Lights/281589394900?epid=1443570632&hash=item4190092dd4:g :kSgAAOSwG9Fbzdsu:rk:1f:0

As the others said, I think fabricating your own adapter is wishful thinking. At least, doing it cheaper than the cost of one already available.