Home made timing meter

[Ratau]

With the lack of funds and not a lot off timing meters around I decided to improvise and made my own timing meter. I machined a brass fitting with a 5mm hole thru the axis off it to screw into the glow plug hole, then fitted a quartz rod as a window pressure tight into the 5mm hole. Next came the electronics; connected at +12 volt a phototransistor (mounted on the back off the quartz rod) a resistor to limit the current to a hi-bright white light emitting diode all connected in series to negative.The LED is mounted above the timing marker in front off the engine. That's my timing meter, one hour labour and the components was less than $10.

I painted the TDC mark on the vibration damper white, so what I saw at idle RPM on the vibration damper was not a single white line but almost a one inch wide white image. If I am correct that is the fiscal time duration of combustion. At idle the image started at 4

[gmctd]

Ingenious, Ratau!
Necessity is the mother of invention.

You just may have put Snap-On and Rotunda out of business! ;)

Good work, man.

[britannic]

What's even better, is that the system is ready to use at any time without grinding your fingers off in the fan etc. Ratau, you should write an article!

If you're getting TDC at 2000rpm, you can afford to advance another degree or two, aim for 4* BTDC at 1300rpm and see how you like it (assuming non-turbo).

[farmerpatrick]

I'd like more details on the components you used.. maybe even a diagram or pic. That's great that you did that.. Adapt and overcome.. That's what we always said in grunts. Lack of funds. Lack of parts. Lack of time. Adapt and overcome.

[Dieselboy]

Excellent work!

[BC Clark]

Well dang! And I thought I was doing good with getting a snap-on Lumy-Mag on Ebay for $180.
That's just all right!

[rke1]

Great job!

Yes, please an article ot at least a drawing and parts list.

Thanks

[mirage]

Sounds great! I would love to get some part numbers and more info on your machined brass fitting.

Contrats! :)

[rhill2901]

I wonder if we could find a brass compression fitting that has the right threads to screw in the glow plug hole... Then just use the compression side on a piece of glass rod.

I'm working on a solution for the white band... If we can take an average of the phase difference between pulses, we can smooth out the pulse variations, resulting in a finer band (or even a line) and a more accurate reading...

[Ratau]

If one look at the commercial timing meters like Snap-On and Rotunda that are Lumy driven what do you see at the timing marks?

Is there a member with electronic background who could fine-tune this idea. The LED is the cheap option, one could add a strobe to it or just hook a standard gas timing meter to it.

Rhill2901 it sound like you have something to add.

How do one put photo's on the forum and what size must they be? I will make a sketch off the diagram ( 3 components plus the window) and post it on the forum.

[britannic]

Ratau, they don't use the timing marks, but instead use a magnetic pickup to send a signal to the electronics and then display the reading. If you still have a timing chain, then I would expect the blur your seeing on the balancer.

Before I installed gears, my MT480 meter needle would wander over a 6* range and the Rotunda unit did the same. These units must have damping/averaging built in, but as soon as I installed gears, there was no longer any drift.

The timing light adapter I had, produced a similar result to the one you're seeing on the balancer.

[Ratau]

If anybody is interested in how I build the timing devise tell me how to put photo's on the forum and what size must they be? I will make a sketch off the diagram ( 3 components plus the window) and post it on the forum.

Danie

[Polar Diesel]

Brittanic- what difference does it make with timing if you have a turbo? You said aim for 4 BTDC at 1300 rpm. Just wondering.

[britannic]

The turbo boost creates higher pressures which speed up combustion. Add extra fuel and the static timing will need to be slightly retarded to lower the pressures and preserve headgaskets and piston crowns.

On my original engine running 13-15psi, I found 2.6* BTDC was optimal, however, different engines, mileage wear, pump model, air intake, injector type and diesel cetane values cause variations, so use 4* BTDC as a guide only and experiment with your configuration.

[Polar Diesel]

Is a gear drive a worth while investment? I know my timing chain is stretched way out. i can hear it rattle at idle. I can see how this would throw timing off in either direction. When i bought the truck it wouldn't start very good, real smoky and smelled raw. the timing was factory, but after i bumped the timing it smells clean and starts instantly. i moved the pump about 3/16 of an inch.

[CleviteKid]

Polar Diesel:


YES ! ! !


Dr. Lee :cool:

[Salemone]

I think you can make that stripe into a line by triggering a oneshot circuit into the led. It would trigger on the leading edge of the flame
front and it will not matter how long it burns.
Thats just a suggestion --When you post the circuit and pics I will try to add to it and make it display a line.

[garysleeman]

Ratau,
Can you please post the circuit drawing for your home made timing meter.
Thanks

[moondoggie]

Good Day!

Salemone: Dang, you stole my thunder. I was going to suggest differentiating the signal & eliminate the negative (flame done) pulse, but a one shot would be much better.

I wonder if a guy couldn

[Moses]

Ratau,

there's an IMAGE button on the Post A Reply page, below the text box as you're typing.

BUT, the images must first be posted on the web elsewhere before you can link it into the forum here.

good luck, sounds like you should patent your moefladger

[britannic]

After installing my gear drive, the engine was almost Duramax smooth (only almost though, it is a 6.2L after all :D ).


Originally posted by Polar Diesel:
Is a gear drive a worth while investment? I know my timing chain is stretched way out. i can hear it rattle at idle. I can see how this would throw timing off in either direction. When i bought the truck it wouldn't start very good, real smoky and smelled raw. the timing was factory, but after i bumped the timing it smells clean and starts instantly. i moved the pump about 3/16 of an inch.

[opto]

Is the thread on the glowplugs M10 x 1 ?

I think it really wouldn't be that hard making a timing meter similar to the proffesional ones (Snap On or Kent Moore), but of course you would have to start with manufaturing the probe.
My main concern is just where to get the quarts.

[Ratau]

Opto

The glow plug screw tread is M10 x 1mm.

The quartz? I am a scientific glassblower so I use quarts every day. Try to find a glassblower close to you and ask for a piece off rod. I used a Swagelok union with a Teflon ferrule to keep the quartz rod in place. This way it

[NH2112]

I was wondering if a used glow plug with the tip broken off and the center drilled out for a piece of lexan rod would work - Snap-on wants something like $225 for the lumy probe and that's more than I paid for the meter!

[Dezman125]

Phil
I have a couple of spare snaponlumi probes.
I'll let them go for a lot less than a new one.
Let me know at salecker@yknet.yk.ca if you are interested.

[garysleeman]

I have everything I need to assemble Ratu timing light except the quartz rod. The cheapest place I have found has a $35 minimum order. What diameter rod should I use 3mm or 6mm? 3mm closely matches the diameter of the phototransistor but 6mm matches the size of the glow plug element.
Thanks.

[Ratau]

The quartz I use is 5mm. I first installed it without the photo transistor to see how much light there is. The flash is so bright one could use a length off optical fiber to do the job. 3mm or bigger will work fine and then you don't need anything else.