Any Transistor Ignition, (TI) experts on the board?
 

I am trying to find out for sure which wire is + and - on the pick-up coil? There is one solid white and one white with a green tracer. I need to know this because I am using this old TI pulse distributor to trigger an MSD . To be wired and run correctly, I need to know this info. None of the Delco info I have or any of the wiring diagrams clearly point this out. Thank you in advance.

Any ti experts
 

Do a search for Dave Fiedler, who has been doing ti repair/restoration for last 40 years.

Peter Serio who posts here will probably know. Very knowlegeable on the elec stuff!

You're referring to the pick-up in the distributor, correct?
(why not use a HEI one?)


I think the white is + and the white with green tracer is - (negative)


:confused:

Thanks for the replies so far. Dave Fiedler I haven't spoken to since I did this same thing in the mid 1980's. A blast from the past! I will look him up. Hope he is well. Peter Serio restored the speedometer on the 62 Catalina in question. It is perfect. Probably more accurate than a GPS now! As far as using an HEI pick-up: It is the same idea but won't fit easily in the old points distributor. Physically quite a bit different in size. I can't use an actual HEI distributor because this engine is a 2x4 induction set-up and it wouldn't fit. I could trigger off the points but the plan is for this engine to run 7000-7200 RPM with a solid lifter cam, and point bounce becomes an issue. The best of both worlds would be to trigger the hidden MSD off this points style distributor with the magnetic pick-up inside. I have three of these pick-up coils if I just knew what the polarity was? If I were to guess, I would agree with you. In home wiring, green is ground, so my guess is the white/green tracer is -. Just trying to confirm. Thanks

Here is a schematic of 67 TI wiring:


http://forums.maxperformanceinc.com/...1&d=1605730805


Sounds like you need just the polarity of the #1 and #2 ?


Here is a MSD diagram, which uses the HEI which this TI is basically the same idea.


http://forums.maxperformanceinc.com/...1&d=1605730805






And the wiring colors for different brands:


http://forums.maxperformanceinc.com/...1&d=1605730805




As said, green is usually ground, and I have a pic of the 67 TI having the connector from the TI control unit to distributor as being White connecting to white and Green connecting to White/green tracer (which is on the pick-up in dist).


So, up to you I guess.


:confused:

Thanks for that information and the diagram. The truth is there really isn't a positive and negative. It's just a coil of fine wire with two leads coming off it. It's a tiny generator that has magnetic induction produce a small AC output. But both MSD and even Delco make a big deal out of making sure the polarity is correct but don't specifically give the wires a polarity. Delco shows the connector and wire colors and says make sure you plug it together correctly. End of story. MSD says make sure the polarity is correct but only calls out the newer HEI coil which is white and solid green. White seems to be consistently called positive by MSD so I will try it that way. Thanks for the help everyone.

I wanted to end this thread with what could be useful information to anyone else wanting to use a TI distributor to trigger an MSD box. After an exhaustive look through the internet and calls to Dave Fiedler, (TI expert), and Peter Serio, (also an electrical and instrument expert), there is no answer yet. But I know how to find it at least. I found an obscure tech bulletin from MSD that addresses the issue and why the polarity matters. It has to do with what MSD does with the signal from the magnetic pick-up coil. One of the pick-up coil wires is grounded inside the MSD box. The other lead goes to a power transistor to trigger the MSD. The only way to know if the polarity is correct for sure is to test it on a running engine. Hook it up one way and set the timing to some number, say 10 degrees. Then reverse the two leads on the pick-up coil. Start the engine and look at the timing now. If the timing is more advanced than it was the first time, say 25 degrees, it is WRONG NOW. Change it back the way it was. If it is retarded now, it is correct. Leave it as-is and readjust the timing. This would be correct for all MSD Boxes that are analog type like a 6AL. If you are running an MSD digital box, the results need to be reversed. You want the pick-up coil to be the most advanced. Why is this? It has to do with the logic in the MSD boxes. You have to remember the pick-up coil produces an AC sine wave. The analog boxes trigger off the trailing edge of the wave and the digital boxes trigger off the rising side of the wave. Hope this makes some sense. Once I get all this in the car, I will post up what wire colors do what and that will end the story.

One question.
Does the TI distributor have a module in it like the 4-pin module in a HEI?
Or just the star thingies? (another technical term :D)


:confused:

The Original TI distributor is an iron body distributor and uses the same rotor and cap as the points unit. The entire breaker plate is replaced with a pick-up coil, pole, piece and reluctor, (thingie). No module. The "Module " is a separate amplifier box mounted near the core support. I will not be using it at all. They were very trouble prone due to the germanium transistors back in the day. The MSD box will replace it. Why not just use an MSD distributor? I have 2 of these units and with the box hidden it will look just like a stock points ignition but pack 45KV, accurate to 9000 RPM's and have a rev limiter. Kinda cool.

That's what I figured, but never saw one in person.

The setup would be just like using a HEI by taking the module out and using the MSD 7al2 for everything.
(like I have done)

Are you using the 8860 cable to connect it?

:)

I honestly don't know the number. I am trying to build this Catalina engine with 30 years of misc. Pontiac bits and pieces I have had laying around . The cable I am using is 3-4 ft. long has a black connector that plugs into a short pigtale at the MSD box. The other end I cut off to attach to the old TI pick-up coil. The MSD harness has a violet and green wire. The TI pick up has a solid white and a white/green tracer. That is where the polarity issue started. Thanks again for the help and drawings.