Follow up test with a CDI ignition

[92b]

I can test ALL these distributors as stand alone parts. And what I’m telling you is that IF the distributor has SOME retard it’s far enough up the RPM scale that most guys would never need to account for it.

This would be an interesting video. I'm sure many on here would like to see how the distributors compare to each other. I understand you are a busy man but hopefully you can find the time to do this. Keep up the the good work.

 

[Newbomb Turk]

This would be an interesting video. I'm sure many on here would like to see how the distributors compare to each other. I understand you are a busy man but hopefully you can find the time to do this. Keep up the the good work.

No need for me to do it. I know the answer.

I’ll wait for someone else to spend the time and effort to show how wrong I am.

That should be very easy to do if I’m wrong.

 

[BillGrissom]

Cool setup. Doubt even classics shops (ex. Mark Warman's) have a Sun distributor tester. All I have is that old Sears RPM/Dwell Monitor. I suspect what we see in the video with the tester running differs from real life, due to the video frame rate, giving dark flashes as if missed sparks. Your eye doesn't see that since it averages more over time.

My 1965 Newport had a CD box on the 383, with OE points distributor, when bought (Delta? forget). I don't know if it worked as it should. There was a push-switch to change from CD to just pass-thru points. Seemed less than robust since just a thin ribbon cable to the distributor terminals. Switched to a Crane Cams XR700 optical trigger pickup ~1996, and now an e-distributor triggering an 8-pin GM HEI module and their coil.

 

[Newbomb Turk]

Cool setup. Doubt even classics shops (ex. Mark Warman's) have a Sun distributor tester. All I have is that old Sears RPM/Dwell Monitor. I suspect what we see in the video with the tester running differs from real life, due to the video frame rate, giving dark flashes as if missed sparks. Your eye doesn't see that since it averages more over time.

My 1965 Newport had a CD box on the 383, with OE points distributor, when bought (Delta? forget). I don't know if it worked as it should. There was a push-switch to change from CD to just pass-thru points. Seemed less than robust since just a thin ribbon cable to the distributor terminals. Switched to a Crane Cams XR700 optical trigger pickup ~1996, and now an e-distributor triggering an 8-pin GM HEI module and their coil.

Thanks for reminding me of that Bill.

Some of what you see in the video of the arrows missing is just the speed of the camera.

I’m close enough to see the spark plugs missing, and sadly that doesn’t show up worth a crap in a video either.

I was going to edit my post to say that. You are correct though. Some of what shows up in real life isn’t shown by the camera.

 

[MadScientistMat]

You have yet to explain how the Chrysler Gold box I had would show 1 degree of retard at 10k. With a Chrysler magnetic trigger. Was it the box. The distributor? Some of both?

To play Captain Obvious, the right answer is "All of them." Any point in the system can take timing out, and when that happens, ain't nothing putting it back in. So for a system to hold the timing that steady, the chain must have no weak links.

Sometimes that point is even a component in a system. Hypothetical example: A particular CDI box might have very little retard with a points or optical trigger, and you have a particular Gold Box and magnetic pick-up distributor that has very little retard, but pair the exact same CDI with the the distributor from the Gold Box combo and you suddenly get 6 more degrees of retard. What happened? The magnetic pick-up conditioning circuit in the CDI box just didn't react as fast as the one in the Gold Box. (Maybe running the Gold Box to the points trigger would get back some of your timing!)