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Discussion Starter · #1 ·
Magneto

Trying to figure out what is going on with my 69 GT.

The previous owner installed a magneto to replace the points, and I was wondering if anyone just had a wiring diagram for a magneto lying around.

Also He grounded out the top of the coil to the body; which, also seems rather absurd.

Any ideas before I start moving wires around?

Thank You,

Sean
 

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i have seen grounded coil caps before. they are used when you run a JACOBS ignition. i don't know if other fancy ignition systems use this method? I used a jacobs on one of my 914's and there was a noticable difference.

on another note, i have a complete unopened Jacobs system for an Opel gt. i bought it years ago, and now that i am swapping a 2.3L turbo into my opel i will not need it. It is for sale.

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Well, now you BOTH have my attention.

A magneto in an Opel? I am familar with magneto ignition systems, but only in lawnmowers (Briggs & Stratton, Tecumsehs and Lawn Boys, from 3 HP to 5 HP) and in very large industrial natural gas fired engines (Waukeshas, Caterpillers and Whites, from 65 HP to 2650 HP). What system would fit an Opel? A magneto (in it's simplest form) is a spinning magnet and a stationary inductive coil, with a set of points to collapse the induced primary field. The main advantage is that they are "standalone", in that they don't require a battery to provide primary voltage to the coil. You wouldn't actually be referring to a Capacitive Discharge system, would you?

And what is a "Jacob's Ignition System"?

TIA
 

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all right guys, let the newbie clear things up...(hah)

I am also familiar with magnetos, my jetskis use them. but what I think what Sean was talking about was a magnetic pick-up instead of points in his dist. like a pertronix.

Jacobs is a company that makes an ignition system that 'uses the spark plug to measure the condition inside the combustion chamber' at least that is what they say. but I have no reason to doubt them, it seems like the system works. it makes sure that all of the fuel is burned by giving a multiple spark discharge. but does not give you multiple sparks if they are not necessary. it also allows you to run .10-.25 bigger gaps! that gives you a lot more surface area on the spark, giving you better combustion.

here is a quote from their site...

'Jacobs' computer-controlled ignitions "modify spark output in response to changing environment and running conditions. By tailoring spark voltage, duration, and phase angle for each cylinder on every power stroke. Jacobs Electronics' computer-controlled ignition systems improve performance, gas mileage, engine life, and lengthen intervals between tune-ups.'


like I said, I have run they on my porsches, and noticed a seat of the pants difference.

but this may not help Sean get his Opel running. does it run? is this how you got it? is it the coil to dist wire that is grounded? or just one of the smaller tabs (which should be grounded) maybe post a picture. but I do know that it was OK to unground the coil and return the wire to the dist. this would bypass the Jacobs system and allow you to run on the original system.

hope this wasn't too much...Jon ;)
 

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Discussion Starter · #5 · (Edited)
Yes it is indeed like a pertronix, it is called an omni pack and seems to be working well.

Basically it has three wires running from it; one through an inline 15 amp fuse to the positive battery terminal, the second to the negative battery terminal (But this one is disconnected), a third to the negative side of the coil.

The car runs, got an idle speed of about 1450 rpm though and from what I understand it should be down around 750-800 rpm. Somewhere in that range, well at least under a 1000 rpm. Getting a slight miss (assuming timing here, but haven't adjusted it yet.)

It is the coil to distributor wire that is grounded (comes out of top looks almost exactly like a plug wire in size is heat shrinked to a smaller wire which is screwed into the inner fender well on drivers side.

Note: Disconnecting this wire from the coil doesn't do anything to the engine (while running) at idle speed.

Car was like this when I got it. Basically got wiring problems (probably doing at least some rewiring) Headlights are wired straight from the battery (Only come on when ignition is on and interior light switches for them do not do anything) Tail lights only work when ignition is on. Hit horn and it moves the tach. Basically got wiring problems under the dash (Thinking Here).

Car is a learning project for me, but I do have people who know how to work on cars helping me out (Just not a lot of experience with this particular car).

Sorry for the length and all

BTW Jon I would like to know as much as possible about how your 2.3l turbo swap goes (with whatever pics and such) was thinking about maybe doing that some day. Was thinking about it when I bought my car 8 months ago, just wanted to see how it ran stock first and see where to go from there, and no one was doing the 2.3L turbo swap then with info on line.

Thank You
Sean
 

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Jon, I suspect that you are right about the "magneto" ignition that Sean refers to. I recall at least one manufacturer calling their Capacitive Discharge system a "Mag Discharge" system.

I believe that this type of system often uses the stock points (rather than a new magnetic or optical device) to trigger an electronic relay which in turn collapses the primary voltage to the coil. This saves the points by greatly reducing the current through them, and also results in a higher potential spark plug voltage.

I say "potential", because the actual plug gap voltage will never be higher than that required to ionize the air/fuel mixture in the spark plug gap. A bigger plug gap, or higher combustion pressures (such as at full throttle conditions), will require a higher voltage. So a higher voltage ignition system is only beneficial at the "margin". But a bigger gap will cause a larger, hotter spark, which can better ignite a mixture that might otherwise cause a "mis-fire".

The "Pertronix" system is just a magnetically triggered relay, that utilizes a "Hall Effect" system; a small iron post passing by a magnet creates a voltage spike that triggers an electronic relay, which merely is a substitute for the points. Other systems used optical triggers, such as the Allison, which can be seen on ebay right now at:

http://cgi.aol.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33691&item=2400808563&rd=1

Sean, if you have a Pertronix system (which looks like a little black block of plastic where the points usually reside), there is a discussion on the wiring on this site at:

http://www.opelgt.com/forums/showthread.php?s=&threadid=665

HTH
 

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is the omni pack blue in color? if so it is a jacobs product. they sold a system called an 'omni pack' it should be blue anodized alum. and have blue plug wires. it looks looks like a block with a couple wires and a male spark plug end coming out of it. you could have a $300 ignition system there...
 

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Discussion Starter · #9 ·
Here is a picture and it does indeed say Jacobs on the side close to the bottom.

Guess I need to know if this thing is wired correctly now and how to set the timing with it or is it the same as without the box?



Thank You,
Sean
 

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