Can anyone identify this please
Thread Starter
Melting Slicks
Joined: Apr 2010
Posts: 2,794
Likes: 1,195
From: Canberra Australia
2025 C3 of the Year Finalist - Modified
Can anyone identify this please
Hi
I am trying to identify the pointless ignition used in my 71 SB Corvette.
It is 2 wire.
Any help would be appreciated
I am trying to identify the pointless ignition used in my 71 SB Corvette.
It is 2 wire.
Any help would be appreciated
Le Mans Master
Joined: Dec 2003
Posts: 5,727
Likes: 38
From: Fremont CA
Pertronix Ignitor I original design. You should make sure to use a ballast resistor or that the factory resistor wire is still in place so coil voltage runs around 9-10VDC. If you try to run full 12VDC across it , it won't last long.
Le Mans Master
Joined: Dec 2003
Posts: 5,727
Likes: 38
From: Fremont CA
Thread Starter
Melting Slicks
Joined: Apr 2010
Posts: 2,794
Likes: 1,195
From: Canberra Australia
2025 C3 of the Year Finalist - Modified
Thanks for identifying it for me.
Now I have a couple more questions
From what I read on the Pertronix site an Ignitor I can work between 8 and 12 volts so with or without a Balast Resistor.
I assume my 71 has one in the wiring harness somewhere - How can i check ?
lets assume I have a Balast resister in the circuit..... then from the diagram below the red wire to the module should not be on the coil but direct to 12volts.
What I have is
- the black ignitor wire attached to negative on coil
- the red ignitor wire attached to positive on coil
- a black wire from the harness attached to positive on coil
- a whiteish wire (not plastic but cloth covered) attached to the positive on coil
It has all been working ok since i got the car but....
Connecting the red ignitor wire to true 12v if a balast resistor is in harness may be better.
Does that sound correct ?
Last edited by CraigH; Jul 24, 2010 at 04:12 AM.
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Drifting
Joined: Apr 2007
Posts: 1,970
Likes: 45
From: Cameron Park CA
I believe they specified it be aligned that way so the tach drive would be parallel with the firewall. That way, the tach cable isn't kinked, and there is no need for one of those 90° gearboxes. This image is from the 1969 AIM:
Pete
Thread Starter
Melting Slicks
Joined: Apr 2010
Posts: 2,794
Likes: 1,195
From: Canberra Australia
2025 C3 of the Year Finalist - Modified
So I did a bit of testing and with.....
Ignition On
around 6.5 volts at coil
While Cranking 9 volts at coil.
Battery is a bit low as i have been doing compression checks earlier in the day but what it shows is that there must be a Ballast resistor in the circuit with the higher voltage coming in when Starter is cranking.
I still think I need to change the ignitor's red with to full voltage to be most reliable rather than the reduced (Ballast Resistor) voltage.
yes No ?
Ignition On
around 6.5 volts at coil
While Cranking 9 volts at coil.
Battery is a bit low as i have been doing compression checks earlier in the day but what it shows is that there must be a Ballast resistor in the circuit with the higher voltage coming in when Starter is cranking.
I still think I need to change the ignitor's red with to full voltage to be most reliable rather than the reduced (Ballast Resistor) voltage.
yes No ?
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Measuring voltage at the positive post of the coil should have shown 12v if the points were open with or without a resistor wire.
On the Pertronix I have installed I have always bypassed the original resistor wire and supplied the red wire with unrestricted power directly from the 12 gauge pink ignition wire circuit.
On the Pertronix I have installed I have always bypassed the original resistor wire and supplied the red wire with unrestricted power directly from the 12 gauge pink ignition wire circuit.
Thread Starter
Melting Slicks
Joined: Apr 2010
Posts: 2,794
Likes: 1,195
From: Canberra Australia
2025 C3 of the Year Finalist - Modified
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
With respect, and having done a Breakerless SE conversion last winter on a distributor that is still in the basement, I stayed with points and condensor from NAPA/Echlin. Yes, I did a "tune-up" two weeks ago. I do have the equipment.
Today I took me and the Wife out for a 100-mile drive. I can tell you when those old cars are tuned properly they Hummmmmmm. The electronic versions may do better. I do not know.
I just know the old 1974 ran flawlessly. I stuck my finger up the exhaust pipes when I got home. Nice and grey. No black.
Nice day and drive! Love these old cars when they run well.
Today I took me and the Wife out for a 100-mile drive. I can tell you when those old cars are tuned properly they Hummmmmmm. The electronic versions may do better. I do not know.
I just know the old 1974 ran flawlessly. I stuck my finger up the exhaust pipes when I got home. Nice and grey. No black.
Nice day and drive! Love these old cars when they run well.