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No Advance Mechanism!!

Posted: Wed Aug 12, 2026 11:54 pm
by johnharrill
...and yet it runs.

The 1967 coupe I'm working on had an aftermarket ignition system that was installed by the P.O. I could not determine the manufacturer of the magnetic trigger, so I replaced it with a Pertronix Ignitor II. Also replaced the MSD 6A. When in the distributor, I noticed all the parts of the mechanical advance mechanism had been removed.

But the car ran and drove pretty well. Now, ChatGPT tells me that neither the MSD nor the Pertronix have any provision for ignition advance. The MSD box failed, so I removed it and I'm running with just the Pertronix Ignitor II and coil.
I'm grappling with a dodgy timing light to see how much advance I'm missing.

How is this engine able to rev beyond 2000 rpm with no mechanical advance?

Re: No Advance Mechanism!!

Posted: Thu Aug 13, 2026 7:37 pm
by Stefan2000
Are you sure that there is no old style timing computer or programmable timing computer like the MSD 8980 or MSD 8981 hidden underneath your dash?
They were products from the 80's that eliminated the need for a mechanical advance system and were usually connected to an old MSD 6 ignition box.

Re: No Advance Mechanism!!

Posted: Thu Aug 13, 2026 10:10 pm
by johnharrill
Nope.

Re: No Advance Mechanism!!

Posted: Fri Aug 14, 2026 8:30 pm
by Stefan2000
Well, it's not unthinkable that if you set it to static timing of around 25 degrees that it will run somewhat decent. Might be a bit of a load on the engine at low revs and high load, and it might run out of steam a bit early in the higher revs....

Re: No Advance Mechanism!!

Posted: Fri Aug 14, 2026 10:05 pm
by johnharrill
Put a timing light on it. Definitely not advancing going on.
So, I'm going to retro fit the distributor with the advance mechanism. I see there are a couple of vendors that offer weights/spring/pins as a kit.

Any advise on which set to buy?

Re: No Advance Mechanism!!

Posted: Sat Aug 15, 2026 12:42 pm
by Fanalone

Re: No Advance Mechanism!!

Posted: Sat Aug 15, 2026 1:12 pm
by johnharrill
Thanks.
The Elshout parts look fabulous.

Re: No Advance Mechanism!!

Posted: Sun Aug 23, 2026 7:22 pm
by Luis A
johnharrill wrote: ↑Sat Aug 15, 2026 1:12 pm Thanks.
The Elshout parts look fabulous.
I have dealt with him and he is a clever and capable engineer. His products are very good.

Re: No Advance Mechanism!!

Posted: Tue Sep 01, 2026 4:21 pm
by damien
Hello, I had exactly the same problem.
The mechanical advance mechanism had been removed or welded shut.
The engine ran reasonably well, but was just hard to start.
I rebuilt the distributor using Elshout parts.
Everything works perfectly now.