Starting to rebuild the Allen distributor machine

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67Dart273

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Last summer I bought an Allen "Syncrograph." "distributor tester." It worked, but as soon as I looked inside and moved a couple of wires, the hard old insulation literally crumbled!!! So I decided to modernize it some. Plans are to use (probably) a Mopar ECU for ignition --the machine needs a high voltage source for the timing strobes. With something like the Mopar ECU, I can use EITHER points distributors or breakerless. I may also use a GM HEI module, with a toggle switch, could easily switch from points to breakerless.

For the tach and dwell, (separate meters) I have two "thrift store" meters and plan to simply pirate the boards and rework as necessary for those functions. I've got 6.00? bucks into the small one, and 25 into the large one.

Below, the gutted interior The bottom of the drive shaft is a rubber wheel, and all the mechanical crap is hooked to the huge knob in the front/ center on the lower part of the machine. This moves the drive motor plate up/ down against a spring, and the motor drives the rubber wheel with an aluminum disk. Anyone who has worked on Ariens snow blowers knows this trick.

I still have not figured out how to add text with each photo!!!!

The box of parts is the 1940's era technology. Yes they actually use a coil for ignition. It generates high voltage to fire the strobes and of course was triggered right off the dist. points. Three old tubes, a 5y3 GT dual diode rectifier tube, a 1B3 high voltage damper (used in old TV high voltage supplies), and an 0C3 gaseous rectifier tube

Next two are the tach/ dwell meters, only the boards will be used, my original Allen meters will be used The original tach was fired off the shaft with slip rings, and now I'll adapt one of these tach boards with the inductive pickup, doing away with the three slip rings and brushes

Next is bottom of the strobe wheel. The ring is the slip ring to pickup high voltage, the strobe flash tubes are in the enclosure near top. This will be used pretty much as--is, except a magnet will be attached on the side where the counterweight (bottom) is now, to fire the tach

Below the strobe wheel photo is the brushes holder (top right) for the tach, and the spark gap/ board bottom left is the brush holder and voltage limiter for the strobe tubes. An old 1B3 damper tube (a diode tube) is across the coil output to ground, which turns it into a spike, and limits voltage. The spark gaps here on this board further limit voltage

The chassis photos show the old technology. I started to build a diagram. I may or may not use the transformer. It has at least two low voltage windings, and I may use them for 12V supplies for the tach/ dwell and even ignition The two little square things on the one side are the forerunners of modern rectifier diodes, known as "selenium rectifiers." These may still be used in some battery chargers.

Bottom photo is the horrid, the awful, vacuum pump. Truely a horrid design. I'll find another pump to go in it's place
 

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Very cool Del! But ya lost me at "analyzer" LOL. You know me and electrical:banghead: Do I see a couple of those old "bulbs" I sent you??
 
Love those older machines, but yeah, if i tried to rebuild it i'd fry the last few hairs left on my head clean off.......lol. Can't wait to see it work. At least i know where to get a old points dizzy done right. :thumbrig:
 
Love those older machines, but yeah, if i tried to rebuild it i'd fry the last few hairs left on my head clean off.......lol. Can't wait to see it work. At least i know where to get a old points dizzy done right. :thumbrig:

LOL A big part of this is to do surgery on BREAKERLESS ones too!!
 
OK, so this afternoon I got a very good start on replacing the tach trigger. I still haven't figured out how to add text between uploads, so the top photo is the original slip ring which breaks conduction of the brushes once or twice a shaft rev to operate the original tach circuit.

Below is what I'll replace it with ---a Mopar dist. setup. The shaft is out of a locked lean burn dist, and luckily the dist. machine shaft is 3/8" and I just HAPPEN to have a reamer that size!!!

Next, rough boring the original reluctor shaft, and below that, reaming it to size.

Next, we have machined off the bottom crimp, removed the lock tang, and faced the bottom of the shaft.

The next photo just shows rough progress against an original advance assy.

Next we see the nearly finished shaft. It has been shortened off the top, the reluctor will be installed upside down for more clearance, and the bottom has been counterbored to clear the bearing bore protrusion on the machine shaft, to allow it to sit lower.

Next we see it sitting on the shaft as it would be installed, all I need now is a couple of set screw holes drilled and tapped

Next we see the reluctor on the machine's shaft from below, with the original strobe wheel as it will install on top. The slip ring you see above conducts spark energy to the flash tubes, to operate the strobe for timing and advance
 

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Below we have essentially the circuit involved with the distributor trigger. Do not confuse with above, which is separate and is for the TACH trigger. This circuit below get's hooked to the distributor, either magnetic pickup or points, and ONLY operates the strobe for the degree wheel

So this is a 4 wire Mopar module, with TWO 4 terminal resistors, all in series, to reduce spark output from the coil

The last photo may look like one 'ell of a mess, but in reality this is a very scientific, closely controlled experiment!!!!

The strobe power comes from the coil but it needs nowhere near full output. The original had a huge dropping resistor in series with the coil wire to limit spark energy, was connected to ground through a television (1B3) damper tube, and last, has spark gaps at the slip ring/ brushes board to further limit hi voltage.

So what this experiment produced was a combination of Mopar ECU, and larger resistance than normal coil resistance to "knock down" uneeded coil voltage.

So the lashup will be thus:

To test a Toy/ GM/ Mopar/ other magnetic trigger, I will use a Mopar module.

To test a breaker points dist, it turns out that you can trigger a Mopar module by hooking the points to the distributor male terminal of the two wire connector.

All that's left is whatever (Ford) uses "Hall Effect" triggers, and we'll see

So the "mess" was experimenting with different coil resistors to limit voltage.

IT TURNS OUT that with a 4- wire module, I can take TWO 4 terminal resistors, and wire ALL FOUR resistors in series with the coil, and still have plenty of coil output to fire the timing strobe!!!. This GREATLY reduces the load on a power supply.


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Stock box should be good to 3500, eh? That is a project. I may look at my 1950's drill press and find out why the spindle is wobbly...
 
TACH The tach will be triggered off the shaft trigger pictured previously, which has really, nothing to do with the distributor. I plan to use an LM 2907/ LM 2917 chip, which should be able to trigger directly off the Mopar reluctor/ pickup

Data sheet

[ame]http://www.ti.com/lit/ds/symlink/lm2907-n.pdf[/ame]

Should be pretty simple

LM2907-tachometer-circuit.jpg
 
Stock box should be good to 3500, eh? That is a project. I may look at my 1950's drill press and find out why the spindle is wobbly...

Remember, the machine shaft only has to go to 1/2 crank speed. I plan to experiment with the Mopar boxes I have (about 6?) to see if any "fall down" at higher RPM, or if they effect timing


I can easily do that by either subbing an HEI module for the Mopar box, or maybe using a points dist, and first triggering the strobe off the Mopar box, then wiring the points to coil NEG just as it originally was, thus eliminating any possible timing effects from the ECU
 
wow. this is awesome stuff you are doing. i know nothing about any of this sorta thing...so when this is all done, will you be able to figure out what distributors have for curves, and be able to dial in or tune a dist. with different weights and springs for performance applications? sorry for such a dummy question...
 
Not dumb at all, and in reality, you can do your own distributors with a little "homemade" stuff.

I think it might have been crackedback ?? showed a simple way of using a protractor and straight edge to measure how far an advance moves

One guy's home method:

DSCN0234Large.jpg


The object is this:

1---Have a way to spin the distributor and to measure that RPM. You have to know "at what RPM" the advance is kicking in

2---Preferably -- as this one did originally, and will when repaired, trigger a tach directly off the machine drive shaft, so that any problems in the dist do not affect RPM readings

3--Trigger a timing strobe off the distributor. THIS IS the big big key, because these strobes can be read all the way around as the dist. fires, thus showing you VERY quickly if a shaft is bent, loose, worn, etc, and of course the strobes tell you what the mechanical AND vacuum advance is doing.

4--Vacuum pump with a controllable needle valve and accurate vacuum gauge, so that you can test vacuum advance units. Very easy, you just open the valve, and see what the advance is doing at what vacuum

Here is a photo of the strobes in operation ---this is a Sun, not an Allen, but the idea is the same. I believe this is a V12 dist. You can see one weak strobe down right at the bottom, one big one in the middle, and one up by the person's thumb. If these do not read "the same" all the way around, they show that bearings are worn, shaft is bent, etc, because each time the points fire or the trigger "triggers" it should happen exactly so many degrees apart (45*) on a V8, or 90 at the crank

The one below is every 60*

http://www.tomyang.net/cars/ferrari719.htm

sun4.jpg
 
Made a Meager amount of progress. Bought some LM-2907 chips to rebuild the tach circuit, then decided to try a cheap digi tach on ebay. Just over 11 bucks, free shipping!!

Got the Mopar reluctor "Roughed in" still have to do a little work to make that fit. That will be the new tach trigger


Got a used medical vacuum pump (thrift store, of course) mounted, picked up some new 4 conductor wire for the motor wiring and got the motor re--mounted

Mounted the old, empty chassis to measure up so I can mod if for mounting the new digi tach
 

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Well, tonight I decided to "let it all hang out" and do away with the dwell meter. I found this little solid state oscilloscope, which can look at the coil primary, and of course measure dwell time. It's JUST the right size to fit behind the factory meter cutouts

65 bucks shipped to my door

And............got the trigger finally mounted permanently and tested with the tach. That's 4554 RPM distributor RPM, so that equates to 9108 crank speed. I don't think I'll be recurving anything that runs much faster than that!!

The brown board on the bottom is the spark gap and brush holder which communicates spark voltage to the slip ring on the strobe wheel. It's close, but it clears.

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Well tonight I got the tach mounting "roughed in" still need to clean the sub panel. Have not decided to sand it for texture, or paint it black. Waiting for the mini o scope which will go into the bottom hole. I'm pretty sure I can use the original power transformer for the power I'll need for the machine and instrumentation

Any of you remember these torturous devices? I still have my 40 year old Vaco (Now Klein) nibbler

[ame="http://www.amazon.com/Klein-Tools-76011B-Nibbler-Tool/dp/B0000CBJCT"]Klein Tools 76011B Nibbler Tool - Amazon.com[/ame]

76011B%20Nibbler.JPG
 

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Yes, I will look at them as they are boxed up. if easy to get at I will snap a pic of one of them. They are grey though with no guages I think but with degree position wheels
 
I'm really kinda envious. Not sure I could ever warrant having one, but I so want one.
 
yea....if or when ya get set up, let us know! I have one that needs to be tuned for my 318. for a fee of course.. :)
 
WOW ...this thread is impressive to say the least.

i thought i got into everything in detail on a car but i still have a lot of Jedi training to left to do.
 
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