Points vs Pertronix Article by Rob Siegel

[Kuntacharlie]

For those interested in more info on the points vs Pertronix debate there is an article by Rob Siegel ( Hack Mechanic ) on the Hagerty Insurance web site that you may find interesting.  Its a good primer on the issues with both systems.  More importantly,  there is some good preventative info on some things that will kill a Pertronix.

 

https://www.hagerty.com/articles-videos/articles/2019/01/21/ignition-debate-points-vs-pertronix

[landon]

Install them correctly with the right resistance and the right unit for the application and they will last for at least 15 years and 125k miles like mine has.

[jimk]

He should have proofed it technically.  Maybe it was late at night after a couple of --

"When the points are open, current is sent through the coil’s primary windings, creating an electric field. This sets up a magnetic field in the coil’s ferrous core. "

and master tinkerer would you agree ?

"This makes the point gap smaller, which in turn increases the “dwell” and decreases the amount of time that the coil has to charge up before generating the next spark"

 

Edited January 31, 2019 by jimk

[jimk]

Here is a primer extracted from The Antique Outboarder magazine written in plain language.  See the scope trace on the bottom of the second sheet.

Inductive ignition.pdf

['76mintgrün'02]

18 hours ago, jimk said:

and master tinkerer would you agree ?

 

yes.  I agree with you.  Higher dwell = longer charge time. 

 

Plugs fire when points open, which happens later with longer dwell times; so as dwell increases, timing is retarded.  (thank you (jimk) for making that clear to me a while back)

 

As the rubbing block wears down the gap decreases, which increases dwell and retards timing.

As the points' contacts wear down the gap INcreases, which DEcreases dwell and advances timing.

 

Using a dwell meter to monitor which way the parts are wearing can clue you into the need for a different condenser; since they have to get along well with the coil to keep from burning up the contacts.

 

The more common way for them to wear is having the rubbing block get shorter; due to a lack of lubrication, or the center post's lobes having gotten rusty/rough/abrasive.  

 

Polishing the lobes on the center post will help keep the rubbing block from wearing and the dwell will not change as quickly.

 

If the distributor has a worn out center post/cam lobes, Pertronix will be an improvement, since the magnets in the trigger ring will restore accuracy. 

 

This one is worn-out, imo.  It needs a PerTronix.  

(here is a pretty one)

 

Side to side play in the shaft is more of a problem with points than Pertronix, so the Ignitor is a good BandAid then as well. 

 

Pertronix are also an UpGrade for people who refuse to use a dwell meter to set their points.

 

For the cost of a PerTronix, you can buy a nice variable advance timing light with built in tachometer, dwell and volt meters.

 

I have to admit, much of the appeal of points comes from having made mine adjustable.  (sorry for the sh!tty video)

 

Tom

[Conserv]

21 hours ago, landon said:

Install them correctly with the right resistance and the right unit for the application and they will last for at least 15 years and 125k miles like mine has.

 

Way to go!

 

Fifteen years ago, I had no idea that Pertronix existed... ?

 

Regards,

 

Steve

 

[thehackmechanic]

Whoops! Sorry about the mistakes. No alcohol or drugs involved; just too many late nights. Shame on me. Thanks for catching them. I have it correct in the books. I'll see if I can get Hagerty to correct it.

 

As a very small issue, I wouldn't say that "As the points' contacts wear down the gap INcreases, which DEcreases dwell and advances timing." The issue that I see with the point gap isn't that it loses metal and wears down and yawns open, but that the points pit and burn, which causes the gap to decrease, the dwell to increase, and the timing to retard.

 

The main, uh, point, I was trying to make is that, with points and condenser, the point gap "wears," which in turn causes timing to change, and that an advantage to Pertronix or other electronic triggering is that it stops that.

 

Thanks again.

 

--Rob

[Tdh]

58 minutes ago, thehackmechanic said:

 

As a very small issue, I wouldn't say that "As the points' contacts wear down the gap INcreases, which DEcreases dwell and advances timing."

 

He was referring to the  contact ("rubbing block") that rides on the distributor shaft that opens the points, not the contacts themselves.  As the contact ("rubbing block") wears out, the contacts gap will decrease not increase.  

Edited February 1, 2019 by Tdh

[Tdh]

2 minutes ago, Tdh said:

 

He was referring to the  contact ("rubbing block") that rides on the distributor shaft that opens the points, not the contacts themselves.  As the  contact ("rubbing block") wears out, the contacts gap will decrease not increase.  

Sorry.  quoted my own post by accident.  Disregard. 

Edited February 1, 2019 by Tdh

[Simeon]

1 hour ago, thehackmechanic said:

Whoops! Sorry about the mistakes. No alcohol or drugs involved; just too many late nights. Shame on me. Thanks for catching them. I have it correct in the books. I'll see if I can get Hagerty to correct it.

 

You are forgiven!

 

The one I always get wrong is the rotation direction of the distributor. It’s 50/50 and I always seem to guess wrong. 

[Flamingo 5]

When Pertronix die, they  die completely, oftentimes at 10:00pm

in the middle of nowhere rural

south Carolina , where there is no Cell towers.

just change points, breakers and condenser with each oil change.

 

[02dag]

 

 
Side to side play in the shaft is more of a problem with points than Pertronix, so the Ignitor is a good BandAid then as well. 

Regarding shaft play. this is often caused by a loose screw inside the shaft. This holds the shaft tight. Very often it is only needed to retighten this and the shaft play goes away. What I want to say, do not throw away your distributor check that screw first.



Sent from my iPhone using Tapatalk Pro

[TobyB]

Can you show us an image of this screw?

 

t

 

[halboyles]

7 hours ago, West Palm 2002 said:

When Pertronix die, they  die completely, oftentimes at 10:00pm

in the middle of nowhere rural

south Carolina , where there is no Cell towers.

just change points, breakers and condenser with each oil change.

 

Can someone give me an amen!

['76mintgrün'02]

17 minutes ago, TobyB said:

Can you show us an image of this screw?

 

The distributor that is on my car now has that screw inside the center post.  You can see it in this photo.

 

all of the other ones I have seen/worked on have a little wire circlip that locks the post onto the shaft. 

 

This one is 0 231 168 021 and has a date mark inside, indicating 1996.  I assumed the screw was a later modification, meaning I've never seen one on an older (original) model... but my exposure's been limited.

 

The special tool shown in the photo above can be used to overpower the wire circlip on the other style, in order to remove the center post from the shaft.  With the screw type, all you need is a Phillips screw driver.