Reworking a Stock Distributor to Trigger MSD Ignition Systems Part 1

Click Here to Begin Slideshow For greybeard hot rodders and racers, it seems it wasn’t that long ago that hopped up point trigger ignition systems were the standard for performance. A dual point setup was the cat’s meow, and so was a recurve that suited the vehicle. You’d swap in quality points, a good condenser and an aftermarket cap and rotor. The next step was to baseline the point gap with a feeler gauge. In theory, if the point gap is correct, the dwell should also be correct or very close, but a dwell meter allowed you to get it right on the money. So far so good, but today dwell meters, along with points, seem pretty much obsolete. Where you once found points front row center at the local auto parts store, they no longer take up prime real estate, but high quality components are still available from companies such as ACCEL. Let’s back up for second though: Way back in the ‘70s, it was no huge secret among racers that engines simply ran a whole bunch better when the spark was fired by electronic system. Those long duration roller cammed engines idled better and always seemed easier to tune with a good electronic setup. As a side benefit, combinations like the big block Chevy, which were known spark plug killers, actually became easier on parts. Fast forward to the present. It’s still possible to work with the simple systems of yesteryear, and at the same time mix in the wonders of modern electronics. Allow us to explain: With the right mix of parts, a vintage point equipped distributor can be rebuilt and reworked to act as a trigger device for a modern high ignition system such as an MSD 7AL2. That particular setup gives us a dirt simple device to tell the MSD when to fire, and at the same time, it gives us high powered multiple spark and a high quality, easy-to-adjust rev control. Best of all, the complete mix of parts is readily available from the folks at Holley-MSD. If you like simple and easy to work with, it's a great plan. Over the next few issues, we’ll show you how it went together, using a vintage Delco distributor as the basis (and keep in mind, the fundamentals of working with a Delco are pretty much the same as a Ford or Mopar distributor). In this issue, we’ll start the process of disassembling the distributor:

Reworking a Stock Distributor to Trigger MSD Ignition Systems Part 1

Click Here to Begin Slideshow

For greybeard hot rodders and racers, it seems it wasn’t that long ago that hopped up point trigger ignition systems were the standard for performance. A dual point setup was the cat’s meow, and so was a recurve that suited the vehicle. You’d swap in quality points, a good condenser and an aftermarket cap and rotor. The next step was to baseline the point gap with a feeler gauge. In theory, if the point gap is correct, the dwell should also be correct or very close, but a dwell meter allowed you to get it right on the money.
So far so good, but today dwell meters, along with points, seem pretty much obsolete. Where you once found points front row center at the local auto parts store, they no longer take up prime real estate, but high quality components are still available from companies such as ACCEL. Let’s back up for second though:

Way back in the ‘70s, it was no huge secret among racers that engines simply ran a whole bunch better when the spark was fired by electronic system. Those long duration roller cammed engines idled better and always seemed easier to tune with a good electronic setup. As a side benefit, combinations like the big block Chevy, which were known spark plug killers, actually became easier on parts.

Fast forward to the present. It’s still possible to work with the simple systems of yesteryear, and at the same time mix in the wonders of modern electronics. Allow us to explain: With the right mix of parts, a vintage point equipped distributor can be rebuilt and reworked to act as a trigger device for a modern high ignition system such as an MSD 7AL2. That particular setup gives us a dirt simple device to tell the MSD when to fire, and at the same time, it gives us high powered multiple spark and a high quality, easy-to-adjust rev control. Best of all, the complete mix of parts is readily available from the folks at Holley-MSD.

If you like simple and easy to work with, it's a great plan. Over the next few issues, we’ll show you how it went together, using a vintage Delco distributor as the basis (and keep in mind, the fundamentals of working with a Delco are pretty much the same as a Ford or Mopar distributor). In this issue, we’ll start the process of disassembling the distributor:

Reworking a Stock Distributor to Trigger MSD Ignition Systems Part 1 1

This is the starting point: a stock Delco single point distributor. This particular example is a pretty good score – it came out of an über-low-mileage 307. Because of the miles, the shaft bushings are in great shape, but the curve is pathetically slow.

Reworking a Stock Distributor to Trigger MSD Ignition Systems Part 1 2

First things first: Remove the cap and rotor. They’re easy. You’ll be met with this:

Reworking a Stock Distributor to Trigger MSD Ignition Systems Part 1 3

Check the end clearance before going any further. To accomplish this, simply use a feeler gauge to determine go-no-go clearance between the oil slinger and the gear. This one was huge at 0.065-inch.

Reworking a Stock Distributor to Trigger MSD Ignition Systems Part 1 4

Next, knock out the roll pin on the distributor gear.

Reworking a Stock Distributor to Trigger MSD Ignition Systems Part 1 5

This photo shows the gear, oil slinger and stock shim pack.

Reworking a Stock Distributor to Trigger MSD Ignition Systems Part 1 6

With the gear removed, you can remove the shaft.

Reworking a Stock Distributor to Trigger MSD Ignition Systems Part 1 7

With the shaft out, this is what you’re met with. Remove the point set along with the condenser. A simple flat blade screwdriver is all you’ll need.

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3 Comments on Reworking a Stock Distributor to Trigger MSD Ignition Systems Part 1

  1. Thanks for the info, I’ll be looking for the next chapter at 72 years young I guess I’m a greybeard with a 55 3100.the new comp270 still needs?
    Thanks

  2. High time. I’ve been doing this for decades, and I have been suggesting it on forums almost as long, and catching nothing but grief for it. And with the quality/reliability of aftermarket modules declining, it’s an idea that is due for a big comeback. Well done.

  3. Gear indexing please explain phasing which way does the gear with the roll pin between the tooth or lined up to single tooth. The old days the index on the gear would align with the rotor tip.

    That’s a great comment! And you’re right. The factory Delco distributor gear has a dimple in it that aligns with the pointer of the rotor (some aftermarket replacement distributor gears do not have a dimple) however the gear can be installed 180 degrees off in order to fine tune the distributor housing position on the engine. For example, if you cannot set the initial timing without the advance canister hitting an OEM spark plug wire bracket or an intake manifold runner, simply remove and reinstall the distributor drive gear 180-degrees and re-install the distributor. Flipping the drive gear will provide approximately 14-degrees of distributor body movement in relation to the surroundings. Installing the gear wth the dimple aligned with the rotor pointer is important in Corvettes with ignition shielding since it has to fit a pre-determined opening. Some aftermarket camshafts either ignore the indexing layout or they don’t take into account the importance in an early Corvette application with distributor shielding. The bottom line here is, it really doesn’t affect timing. It affects the location of the distributor body and vacuum advance canister in relation to the intake manifold (or the ignition shielding in a Corvette). WS

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