Points vs Pertronix Article by Rob Siegel

['76mintgrün'02]

9 hours 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." 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.

 

8 hours 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.  

 

Well, I was talking about both, but the quote Rob chose was about the contact points themselves.

 

After a bunch of searching (off of this site) I found a quote that further explains why my understanding was incorrect.  ( I assumed metal was being 'removed' or 'burned away', but they say it is deposited from one side to the other.

 

"Problem Areas: Each time the points open, a very small amount of metal is transferred from one side of the points to the other. This transfer is uneven, and in effect closes the point gap. The second problem area is the fiber block that rides on the distributor cam and opens the points. This fiber block not only seats itself on newly installed points, but wears on points that have been in use for long periods of time. The combination of wear and metal transfer will eventually close the points completely, and the engine will no longer run."

 

(Quote taken from here http://cny.mgcarclub.com/electrical_systems.htm )

 

Tom

 

[jimk]

Old timer pro tune up guys had a tool that slips over the cam that has a fine file type surface on the od.  This tool was turned with the points rubbing block resting on it.  This "filed" the rubbing block to better have it better conform to the cam and reduce the initial wearing in of the rubbing block so the dwell didn't drift as much.

The initial wear was more pronounced with the older phenolic material rubbing block than the new plastic blocks.

['76mintgrün'02]

AMEN Hal!  Although points are just getting broken in at 3k miles   for the reason jimk mentions above.

 

This article has a bunch of interesting information on Points/PerTronix.  

http://www.ratwell.com/technical/PertronixAdjust.html

[TobyB]

13 hours ago, '76mintgrün'02 said:

 

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.  

I didn't know there WAS a screw version- see, you learn something here every day.

 

Every one I've ever worked on had that wire clip.  It's NOT an E clip, you're right, and the groove it sits

in is tapered to allow it to come off if pulled.  I spent HOURS on the first one I took apart, making

some very delicate pliers to remove that spring clip... only to discover when it was apart, as you show,

that your special tool does it just fine.  Mine wrecked the spring clip...

 

t

[TobyB]

Quote

This transfer is uneven, and in effect closes the point gap

Huh.  IF you have the absolutely right balance between condenser and coil,

then the transfer IS even.  But I wouldn't expect the Lord of Darkness club to have ever seen that.

People who have more faith in points than I could tell you the effect of mismatch-

too large a capacitance vs too much inductance- but I don't remember.

 

This does NOT match my experience, btw- if I kept the rubbing block well- lubed,

the point gap would open, but if the block wore faster (yep, the phenolic had to be lubed regularly)

then the points closed up.

I would sometimes hasten that by filing the points in situ, but even just letting them 

go, they would transfer material from the point contacts to the inside of the distributor cap.

Slowly- I think I used to get 15k or more from a set.

 

But I'm a firm believer in modern semiconductors, used in moderation and with due deliberation and hardening.

 

t

 

[Slavs]

Petronix will fail with no warning. And, when they do, your engine will cut out no matter where you are. One of my friends was in the middle of an intersection making a left turn when his Petronix failed with disastrous consequences. The Petronix kits will not fit all 02 distributors. In my opinion, these things are junk.

[Vicleonardo1]

Question: Is it illegal to  have a Petronix installed and have in your trunk: 

A: A backup/old distributor or,  

B: Another Petronix kit? 

 

Just wondering cuz there is a lot if room in the trunk......

 

Edited February 3, 2019 by Vicleonardo1

['76mintgrün'02]

You will also want to have your timing light with you, Vic, if you are going to swap out the distributor.

(I keep mine under the driver's seat, with spare points/condenser in the box).

 

I installed a Pertronix when I first got my car.  I wired it in a way that allowed me to go back to points... which I did, shortly there after.  For a little while, I kept the Pertronix on board in case the points/condenser failed.  (I just liked the irony of that situation). 

 

Condensers can also fail without warning and leave you sitting in the middle of an intersection, or rural South Carolina....

 

It takes some effort to maintain points.  Distributors too, for that matter; but I find pleasure in fixing and maintaining mine. 

 

I understand the appeal of having the constant dwell-angle associated with Pertronix and how it keeps the timing from changing as the points wear down. 

 

Typically, we chase the change in dwell angle by adjusting the timing along with it; since adjusting points is more tedious than twisting the distributor a little to compensate.  With this gadget installed, it is now easier to adjust the dwell than the timing. 

 

By bringing the dwell back to the initial setting (with the engine running), the timing is simultaneously reset.  

 

  (dwell meter upper right)

 

It is true what Slavs says about different distributors requiring specific Pertronix units.  I installed mine in an 002 distributor and the switch was not being triggered at the correct time.  That became evident after a bit of use, when looking at the underside of the distributor cap.

I had made a phone call to Pertronix to be sure to buy the proper model for that distributor, but the one they recommended was   not   quite   right.  It was   firing   too   late. 

 

I paid $100 for that silly thing.  I suppose that experience fueled my disdain.

 

Tom

[Jimmy]

8 minutes ago, '76mintgrün'02 said:

You will also want to have your timing light with you, Vic, if you are going to swap out the distributor.

(I keep mine under the driver's seat, with spare points/condenser in the box).

 

I installed a Pertronix when I first got my car.  I wired it in a way that allowed me to go back to points... which I did, shortly there after.  For a little while, I kept the Pertronix on board in case the points/condenser failed.  (I just liked the irony of that situation). 

 

Condensers can also fail without warning and leave you sitting in the middle of an intersection, or rural South Carolina....

 

It takes some effort to maintain points.  Distributors too, for that matter; but I find pleasure in fixing and maintaining mine. 

 

I understand the appeal of having the constant dwell-angle associated with Pertronix and how it keeps the timing from changing as the points wear down. 

 

Typically, we chase the change in dwell angle by adjusting the timing along with it; since adjusting points is more tedious than twisting the distributor a little to compensate.  With this gadget installed, it is now easier to adjust the dwell than the timing. 

 

By bringing the dwell back to the initial setting (with the engine running), the timing is simultaneously reset.  

 

  (dwell meter upper right)

 

It is true what Slavs says about different distributors requiring specific Pertronix units.  I installed mine in an 002 distributor and the switch was not being triggered at the correct time.  That became evident after a bit of use, when looking at the underside of the distributor cap.

I had made a phone call to Pertronix to be sure to buy the proper model for that distributor, but the one they recommended was   not   quite   right.  It was   firing   too   late. 

 

I paid $100 for that silly thing.  I suppose that experience fueled my disdain.

 

Tom

 

If ran a Pertronix, I would wire it with disconnects, get it all dialed in, remove it, install another one exactly like it, store the "known good" one in the car as a spare and never give it a second thought.

['76mintgrün'02]

That sounds like a fine $200 plan to me.  Makes perfect cents.

[Vicleonardo1]

3 minutes ago, '76mintgrün'02 said:

That sounds like a fine $200 plan to me.  Makes perfect cents.

 

Vs a $500 1-2-3? I wonder how centsable that would be?

It appears there isn’t a wrong approach, just what one’s preferences and pocketbooks allow. 

 

If I wasn’t running points at the moment, I would go with a Pertronix  with some sort of backup.

 

Cheers!

[Jimmy]

12 minutes ago, '76mintgrün'02 said:

That sounds like a fine $200 plan to me.  Makes perfect cents.

 

It's $160, which I concede is a lifetime of points and condensers. The way my luck goes, having a spare in the car would guarantee the one in the dizzy would never fail. I should just buy a spare 2002 and I'd never have to work on my car again. I guess that only works if I take them both everywhere! ?

[Simeon]

19 minutes ago, Jimmy said:

 

If ran a Pertronix, I would wire it with disconnects, get it all dialed in, remove it, install another one exactly like it, store the "known good" one in the car as a spare and never give it a second thought.

 

... but how would you know that it didn’t get damaged when you removed it? 

 

I have no direct experience of Pertronix brand ignitors but I did have a HotSpark type installed in a distributor that I removed in a working condition and then tried reinstalling the distributor a year or so later and the HotSpark had failed. 

 

I wonder if you could install two, on opposite sides of the cam / magnet? You could then wire them in series and they would be dual redundant. You would need to work out a way of showing one had failed otherwise it could fail and you don’t notice until the next one fails. ?

['76mintgrün'02]

For a little while, I couldn't make up my mind; so I ran both at the same time.

[Simeon]

3 minutes ago, '76mintgrün'02 said:

For a little while, I couldn't make up my mind; so I ran both at the same time.

 

That would do it. Genius.