[Scott Stoneburg]

Reading about rotor phasing in a couple threads recently made me think that I may not completely understand the process. I have a sacrificial cap I will use. I would think I should make my "window" to view the rotor pointing at #1 in one of these 2 locations. But recent post indicate I should be making the window at #6 plug terminal instead. I don't know why that would be the case. And let me say I could be completely wrong and just don't understand the process.

[Formulas]

as far as which terminal it does not matter as all cylinders are the same phasing, pick the easiest to view and put your timing light on that cylinder

i did mine from the top used white paint on top of rotor tip for easy viewing

if someone is doing a HEI the side would have to be used but an HEI should be good from factory usually only cobbled together / hybrid systems should need a phasing check

[Scott Stoneburg]

Oh..put the timing light on that plug wire, not sure why I wasn't getting that! DUH!!! Wow. I get it now. Thanks. So wouldn't just cutting the hole and setting the distributor to point to the proper wire terminal work just as well without running it?

[Formulas]

in verifying rotor phasing you want to know where the rotor is in relationship to the cap terminal at firing of a given cylinder

to far away from the proper terminal and the spark energy to the plug may be reduced OR the spark energy could be jumping inside the cap to an adjacent terminal you dont want to fire off

also for those that have mechanical and vacum advance you want to observe phasing during those influences

in completly stock OEM points and HEI units there isnt much need for phasing its engineered in and the rotor is in a fixed position but its when running a bunch of non OE components different triggering options coil option ignition boxes crank mag triggers the triggering and distribution of spark can get out of sync

I bought a MSD cap adapt from HO. racing in the early 80's it has a 2 piece rotor you can phase with

[chuckies76ta]

Scott. I just took a hole saw and cut a hole in the top of one of my used MSD caps close to #1 terminal. My timing is locked out as I'm using a crank trigger. Here is a good read from MSD. https://documents.holley.com/techlib...or_phasing.pdf

[XLR8STEVE]

This video is a simple demo. If you go between 15 and 35 degrees timing, you phase it to be arcing well at all timing points but favor the higher full throttle timing arc length.

https://www.youtube.com/watch?v=aWMlNwGW0tM

[blueghoast]

Originally Posted by XLR8STEVE

This video is a simple demo. If you go between 15 and 35 degrees timing, you phase it to be arcing well at all timing points but favor the higher full throttle timing arc length.

https://www.youtube.com/watch?v=aWMlNwGW0tM

Yea what he said. Thanks alot for this vidio.

GT

[Half-Inch Stud]

Should be mentioned that;

Mechanically pointing a rotor to post 1 ( at TDC for firing 1) doesn't set the spark-event. So then using a timing light is nice, but could the spark-event could be moving further away from the post as desired timing is set. Pretty exciting stuff.

An unphased rotor does indeed affect the pullaway TQ, in my experience if so usually in an aweful way. Backfire pops thru the carb are the typical tell.