Pertronix


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OK so let me test my unit like the picture above. What would I find? Obviously it works to some extent. What would the failure mode be for the symptoms I described? I could heat the unit up and do the test. My miss at 5500 would be indicated by what? My idle issues would be indicated by what?

So lets say the unit is bad. Would you trust another one? Maybe I got the one bad egg. In many years and many sets of various points I have personally never got a bad one. I will grant you somebody has, but not me.

I think in theory a contact-less pick up is a step up and I am dissapointed in what I have experienced. So I will pull my "old fart" card and stay old school, for now.

Any new Pertronix reviews?

Wondering since in today’s world it seems a lot of products change over time; materials, the way they are made etc. Also wondering since a customer has requested I install one....

No one seems to mention the fact that Pertronix relies on a solid ground connection .. and 911 engines notorious for poor grounding. Suggest an additional ground to another grounding spot from the dist body may assist .. that’s what I’m going to test on mine.

2 BMW 2002s, one “74 911S, all had pertronix installed as fast as I could get them delivered. About 150,000 trouble free miles. Do what makes you happy. I would never use points again, my lawnmower uses pointless ignition. I hear the Mclaren P1 uses points.......
If you look at the previous posts from the negative posters, you will see a trend.

I used Pertronix but have moved onto a 123 Distributor.

Mycar, How's 123 Ignition distributor compared to Petronix in your car? Was there a noticeable improvement? I'm contemplating on replacing my stock distributor with Petronix to 123 Ignition on my 70S

I’ll weigh in here from a ‘sensors’ perspective. Magnetic sensors are generally used to detect when things are open or closed or close to an object. They are good at this job but none of these jobs need to tell you *precisely* when the event happened. Who cares exactly when the door opened?

In a rotating system where a magnet passes a sensor, a variable signal is produced proportional to the distance between the magnet and the sensor. As the system spins the signal will be a sine wave of sorts, peaks occurring as the sensor is close to the magnet. . The sensor will have some kind of threshold circuit that defines the voltage level at which the event occurred - the trigger point.

The voltage level is not only dependent on the distance BUT ALSO on the strength of the magnet. In many of these points replacement systems there are six magnets set into a plastic collar. Unless there is some special selection process, it is unlikely that the magnets are the same ‘strength’, hence the signal produced will vary per magnet. This coupled with a less than precise way of setting the magnets in the collar compounds the problem and results in discrepancies between timing per cylinder.

Most magnetic speed sensors use a single magnet for good reason.

I've been reading this thread and I disagree. Hall effect sensors work great. The type of hall effect sensor used in pertronix turns on and off in a square wave pattern, not a sine wave. Very precise and defined on and off periods. A reluctor and coil sensor operates (basically a small alternator) with a sine wave. Magnet strength doesn't have to be equal either with pertronix, just magnet spacing. The distance from the magnets to the sensor is critical as too wide will result in misfires. Pertronix 1 and 2 both work great for triggering CDIs. The current and voltage stress on the Pertronix is very low in that application just as it is for points. If there is cylinder to cylinder variation it is most likely due to improperly spaced magnets. Poor quality control at the factory. I have a pertronix 1 for a Ford V8 and the variation cylinder to cylinder is precise but that particular pertronix module is very common so they probably had to get it right. Fred

Interesting video comparing points, Petronix , and 123 Ignition.

https://youtu.be/F1PFb46gKlc

Fred, you haven’t understood my points 2 and 3 below.

1) The spacing is critical which is a quality issue. You agree with me on this.

2) Yes Hall sensors work great but they don’t usually have SIX magnets. Each magnet that passes the sensor will produce a slightly different response. Usually in these sensors, the single magnet is built into the sensor.

3) Although the output of the sensor is a square wave, the basic Hall effect before the electronics will be an analog wave so there is a level threshold circuit and point at which it triggers will depend on field strength.

Yes, It's because the output is an analogue square wave that the threshold voltage isn't critical. The rise and falls of voltage are almost instantaneous so the threshold voltage will be at the correct time every time plus or minus maybe a few µS which won't be measurable. The magnet field strength just has to be strong enough so it triggers the hall effect sensor which will be at the same rotational position providing the spacing between the module and the magnet wheel is within the recommend spacing (usually 30 thou). Someone running a 20 year old pertronix will have magnets that have lost some of their oomph yet they still will trigger at exactly the same position. Fred

While tuning my 72 I got it pretty well sorted but still experienced some backfiring. Inspecting the old points they measured 10mm spacing instead of 16MM. Once adjusted the backfiring went away. New points are on order, for $5 and $5 dollar shipping.

While describing this to a Master Porsche Mechanic (highly qualified) friend of mine, he said "install a Pertronix and new coil and be done with it, $200".

I have one in my 2002 BMW, and it works great. That's what I'm gonna do.

Well. ‘almost instantaneous’ is still a slope + problems with setting the magnets IS totally measurable. In some cases as much as 5 degrees variance per cylinder.

I have a Pertronix and it's been working well after a very challenging installation (I didn't find the proper CDI wiring diagram until expending much energy in the wrong direction). It's been working well ever since, but like many others, the durability of the components seems questionable to me.

I've thought about switching to the Crane optical setup, but I've read that dirt can mess with is and at least lately, I haven't found a place to buy it (Pelican as stopped selling them).


I often think about going with a 123 distributor, so I'd love to hear more from people who have made that jump.

123 Solved a lot of problems in my '73 Alfa. Wish I had known about it earlier. Highly approve.

Does anyone know if using the stock CD coil is OK with the Pertronix? the instructions say "minimum of 1.5 ohms for the coil" and the stock Porsche coil measures 0.7-0.8 ohms.

I've a 2.7 with stock CDI / coil
with Webers with Pertronix and it's performed great.

Great. I was sketching up wiring diagrams to make sure I wire it up correctly
Top sketch is with Pertronix. Lower sketch is baseline stock.

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http://forums.pelicanparts.com/uploa...1591827423.jpg

I used Pertronix on a tr6 I restored and it was great, but i ve not heard the same endorsements for porsches. I m curious too if a more current opinion is available

I have had Pertronix in my 1973 2.7 for about 15 years. I will check my servicelog and give the exact time and mileage.

NO problems. I carry a spare set of points and even another Pertronix, but have never needed them. I am talking 100,000 miles of service.

Best $100 I have spent on this car!!

I later installed a good CDI and transformer coil [NOT MSD] and that has made a HUGE difference in my MFI equipped engine.

Install it and forget it....it just works.

That only applies if the Pertronix is directly driving the ignition coil. When used with the original Bosch CDI,
the Pertronix is just a points replacement. Given that, it's questionable if the Pertronix has any real benefit over
the original distributor points.

That sums it up!

The rubbing block experiences no wear ......forever? I doubt it.....well I know it is not true.

Is it again forum rules to quote yourself??? ;-)

I looked it up and the Pertronix was installed 12 years ago and 102,000 miles ago. Has not been touched, and no problems since then.

I guess it is surviving its hot environment that the naysayers claim it will not.

This thread is so old that some posters are using the former names and current log in names, and even quoting themselves!!

Bottom line is the purists are going to tell you that points are terrific and the way Porsche intended. I kind of feel if Porsche had access to Hall effect ignitions when the early cars were built they would have put them in......well in reality they did put them in later models as soon as they were developed and reliable.

If points are just fine for us, and don't question the wisdom, why did Porsche put in a modern system when they were available?

Same goes for the old CDI. Some posters on this thread argue that they are fine and adequate and preferred and even that you will not see any improvement. This has not been my experience. When I switched to a modern CDI [not a red MSD ] it was a huge improvement. Much better starting, better running, better idle, and I get the benefit of a soft PROGRAMABLE rev limiter [no harsh rotor limiter] and data gathering for MAP, RPM, etc..

There are even CDI models now available that look like the old Bosch CDI from Parts Klassic, and others that have modern electronics in a look alike box. These units sell quite well.

Bottom line, make up your own mind. We have seen here guesses that Pertronix will not be reliable, and anecdotal evidence from users including me that they are reliable.

We have also seen claims that points don't lose dwell and never wear out, and our common sense and experience is that they do both.

So it wears a little over 100K miles and the timing might get retarded a little, maybe one degree for all cylinders,
versus random timing per cylinders with the Pertronix.

Well - I installed the Pertronix on the 2.7L distributor in my stock 3.2L w/ 46 PMO carbs and it's no better. Just so hard to start; takes many cranks and many throttle-throttle-sputter-throttle-die-try again - throttle sputter. Was hoping I had an ignition issue (since 90% of carb issues are ignition or mechanical).

Once lit, it does'nt run all that great until warm and RH carb needs the idle mixture screws almost falling out to run best. LH carb is just right - about 2 turns out.
Did full COLD leak down and it looks normal for an ORIGINAL used 3.2l engine

#1 = 5%
#2 = 16%
#3 = 8%
#4 = 13%
#5 = 12%
#6 = 5%

No audible noises or leakage heard during the testing.
RH carb pops - like it's lean. Yes, I've pulled the carbs apart and cleaned/gone thru them with no luck. did'nt find any smoking guns. All three idle mixture screws need full out to run best so it's not one cylinder. All throttles flowing equal air.

46mm PMO Carb specs:
Idle jets = 55
mains = 150
airs = 200
emulsion = F11
WR7DP spark plugs
3 pin Porsche CD box
CD coil

Thinking I may try another set of carbs I have up on the shelf - 40 PMO's and see what shakes.
I am so thru with carbs. It's time for FI but it seems no one makes a complete turn key system.

Jim: Did you try a different CDI? I recently helped a friend fix his 914-6. Very poor starting, bad running poor idle, lots of popping out carbs. Turned out to be the CDI box (components are getting a bit old). There is a specialist that repairs and can test yours, but from your signature, it seems likely that you may have another box around.

If you want FI, why not use the OEM 3.2l injection? Easy conversion as the original computer and injection harness connects with only 3 or 4 connections to your car. Very easy to do.

For those interested, I am at over 150K miles on my points with no measurable wear or adjustments so far. I do lube annually with the Bosch point lube Grady Clay or John Walker suggested many years ago.

Just for clarity, early in this tread I posted about removing the pertronix and reverting back to points. I never had a failure of the Pertronix and the car always ran, just not as good as on points or as good as Porsche designed it to. I tried to explain this with my data, science theory on the unique compact design sacrifices, and the information I received from Pertronix that they never considered or tested for a difference in cylinder timing. This is posted only for those interested in more insights.

That's a good idea - I have other 3 pin CD boxes I can try. Do these CD boxes "lose strength" over time? I also have a MSD unit but was trying to stick to "old school". I got the 3.2L without the intake and wiring/DME so went the route of carbs. I'd put the 3.2L intake on if I had the hardware!
Like you, I've had 911's with points and no troubles. When I went to carbs, I had to find a 2.7L distributor (rotates same as the 3.2L just have to swap distributor drive gear) and really wanted to convert the 3.2L to hall effects while I temporarily used the 2.7L. Figured the Pertronix was a quick upgrade.
After staying up all night reading about PMO carbs, the one thing I didn't do is close up the idle air bleeds to zero before starting my tune/calibration - these are lightly used PMO's I bought off the PP classifieds and unknown used history. So I'll try the CD box change and idle air bleeds today and see how it goes. Thanks for the feedback. I should start a hunt for 3.2L intake hardware and FI setup!

Yes, without going into unnecessary details, there are components that loose important properties with time and heat. You need to test with a known good one.

I used points in my 77 with 80 engine car for nearly 30 years. The point contacts lasted a long time, probably because of the triggering aspect with the CDI others have mentioned. However, the rub blocks seemed to wear so fast that I was going from 35 degree to 60 degree dwells in less than 1500 miles, which obviously affected performance, mileage, and starting. This started with a batch of new points that I stockpiled about 15 years ago.

I just installed an Ignitor 2. Easy installation. I've just gone out for my first test run with great results. Obviously there is still a lot of testing to come but so far so good.