Adjusting Rotor Phase on Duraspark Distributor

[basstrix]

That's a good observation, Hemi, but the screw has 2 ground lugs and the distributor uses the one on opposite side. The coil assy must have multiple applications?

Edit #2: I have wondered about adding a ground strap between the coil's baseplate and the breaker plate. Thoughts?



Edit #1: You might also notice 2 different distributors in the pictures. The older looking one is from my big block engine...that's the blue cap I sacrificed and cut holes in. I'm also using it to snap pictures showing positions of the rotor and reluctor while the Cardone remains installed on engine.

 

[Hemikiller]

Ah, that makes sense, thought the distributor looked a bit dirty for a fresh reman.

Those pickups are used in a multitude of applications. A ground strap can't hurt, even something temporary. You'd think it would be unnecessary with so many contact points to the housing, but....

Is the ground lead connected to anything?

I'd also be suspicious of the pickup coil itself, as it's the only thing moves with the vacuum advance.

 

[basstrix]

Ah, that makes sense, thought the distributor looked a bit dirty for a fresh reman.

It's actually new! One thing people should know about the Cardone....the housing OD, where the cap seats, is larger than a Motorcraft. In other words, you have to use their small to large cap adapter. I learned that when I tried to fit a small diameter HV cap and it wouldn't fit.....I ended up turning down the housing and use a Motorcraft adapter now. I bought it for its 10L advance plate.

Those pickups are used in a multitude of applications. A ground strap can't hurt, even something temporary. You'd think it would be unnecessary with so many contact points to the housing, but....

Is the ground lead connected to anything?

It makes very good/low resistance connection to the DS-1 module, engine block, battery, body sheet metal....

I'd also be suspicious of the pickup coil itself, as it's the only thing moves with the vacuum advance.

I've run the distributor with a drill and had the coil connected to an oscilloscope....applied and released vacuum, tapped the coil with a screwdriver handle....it's rock solid....never skips a beat. I compared it to the motorcraft distributor's wave form and they are, essentially, identical. The slope on the waveform is steeper on the leading edge vs the trailing edge....and the slope reverses when you reverse polarity on the coil. Sure makes a big difference on timing and rotor phase.

In case anyone is wondering, the Motorcraft distributor does the same thing with the noisy signal, but it happens at a higher RPM....above 3500.