My rotor is "short".

[RedFish]

Matched set of cap and rotor may seem "theory" today. "Old school" is more correct. D.I.N. standards were developed in early 1980s . I.S.O. standards followed. I'm older than that.
I'll still always buy cap and rotor of same brand.

 

[snailpower]

Just wanted to say thanks for this thread and add that I had similar findings.

After using an accel cap / rotor for a couple weeks I found this thread and changed out for napa parts (mo3000 and mo30?) The difference is HUGE in idle quality and overall performance. Feels like a different car with no other changes. It even sounds different at WOT.

The rotor length difference is noticeable as well.

 

[67Dart273]

If there really was that much difference there was something seriously wrong, and I doubt very much it was the Accel brand

 

[snailpower]

If there really was that much difference there was something seriously wrong, and I doubt very much it was the Accel brand

Perhaps I overstated the difference. For me its huge from being used to how the car typically runs. If someone else jumped in they would probably not notice at all. Idle smoothness at warm idle is noticeable though.



You can see on the old cap that probably has less than 10k on it the rotor quite hitting the mark.

 

[AJ/FormS]

If there really was that much difference there was something seriously wrong, and I doubt very much it was the Accel brand

I used to file my rotor down on purpose. That forces the coil voltage to rise, and then when it gets to the plugs, it has some real zing to it. Course not every crappy coil can push that hard. So I bought a real coil. I think I could probably weld with it.
I open my plug-gaps for the same reason.
I don't need no steenkeeng MS ptoui D,lol
Seems to me, with all the trouble you are having, a decent coil and matching ballast resistor woulda overcome the situation a long time ago.
Just saying.

 

[67Dart273]

I used to file my rotor down on purpose. That forces the coil voltage to rise,.

There was a big controversy about such things "when I was a kid." At one time, the typical Delco V8 rotor was longer, and at some point Delco started making them shorter. It was for this same reason. At about the same time Champion plugs had started manufacturing their booster gap plugs........I don't remember what they were called, "buzz word" they had a gap inside the ceramic that was supposed to do the same thing. Of course you didn't want "both."

 

[AJ/FormS]

Booster gaps! I barely remember those. I tink dey was for chebbies wit points,lol

 

[mguner]

Back in the day they used to sell these gimmick items to boost your spark that were nothing more than an additional gap in the coil wire. The problem with these short rotors is that they will amplify any indexing issues you may have and the last thing you want is the wrong plug getting fire!