Pertronix ignitor
 

What are the good and bad of converted from conventional point and rotor to electronic Petronius ignitor? Are there others brands of electronic ignitor that best for 1975 911s bone stock. Thanks for your inputs

In my experience, these type of contactless pickups have quality issues surrounding the plastic collar that is put over the distributor shaft.

The collar has six magnets set into a plastic ring. As the magnets pass the sensor, the trigger is generated for the ignition. The first time I saw one running on an engine, a very responsive tacho showed that the RPM was varying up and down with the engine held a constant RPM.

Further inspection with a scope showed that the unit was not firing each spark plug evenly. The conclusion was that the magnets are not perfectly set at 60 degree spacing, which leads to some cylinders firing early and others late.

I've spoken to numerous engine builders since and the conclusion is that you can use these systems but they need vetting, preferably with a distrbutor test machine. One shop I spoke to sends 50% of units tested back to the supplier.

I have one good unit and one bad unit and Jonny is correct as it being a magnet issue. I hear their quality control is not so good there. I am running pertronix in my 77 911 now and have for several years and also have it in my TR4 for years as well and plan on running it in my 68 corvette convertible this Spring too. You can buy the magnets seperately but why should we have to especially like brand new right out of the box!

Well, there you go, 50% failure rate. :)

I have used the Crane optical setup without any issues on multiple cars. These are on CDI ignition cars like the 77. I Have not seen any issues of floating rpm or uneven timing/firing.

Just use points Pertonix is prone to all sorts of problems don't waste your money.

Those are some pos and some neg. I would
Like to hear some more pos/neg before I converted
my 911s to pointer free. Thanks

When they fail in the middle of BFE, you're vulture food. With points, you clean, re-gap, and yer on yer way again.

Pertronix highly recommended
 

MY experience with the Pertronix Hall effect system has been very good.

I am sure there are failures.

I have heard the magnet argument and have run a scope on my car and could not find this alleged problem.

I am sure a Crane optical system will work well too.


I have owned my 1973 2.7 EFI 911 for 20 years. Ran the first 5 with points and it drove me crazy. I could feel the difference as the rubbing block wears away and and the dwell changes. I was adjusting points every 5-6000 miles.

Once I was stranded onside the 101 in heavy traffic because the gap closed.

I got tired of it and put in Pertonix. 15 years and 85,000 miles later the same Pertronix unit is performing perfectly.



"When they fail in the middle of BFE, you're vulture food. With points, you clean, re-gap, and yer on yer way again."
I carry a spare set of points. I carry a brand new extra Pertronix in my tool bag, Have not needed them in 15 YEARS!

"Just use points Pertonix is prone to all sorts of problems don't waste your money."


BEST $100 I have spent on my 911. HIGHLY RECOMMENDED

pertronix - i like 'em - never a problem in 20 yrs
 

i have run pertronix in several 911 engines including race motors, MGB race car, Manx buggy, and several more cars for over 20 yrs - 7000-7500 rpm on the race motors

- variously connected to std oem, MSD & permatune ign systems

never had a problem SmileWavy

if one is totally paranoid about it - carry a set of new points & condenser in your glove box

( such as - i carry an extra HEI ign module for my '84 GM truck HEI cuz i've had a couple of those fail on the road over 30 yrs - Ford Duraspark modules are also known to fail - so if paranoia is your thing - carry modules for every car you own)

I've had Pertronix in my 77 911S for around 10 years.

I had some issues installing by myself......never could get it just right. Got a friend to help and has been perfect ever since.

I'm a fan

The original ‘Ignitor 1’, which I see still being sold, will burn out quickly if the ignition is left on without the engine running. Later versions are supposed to be more resistant to this.

pertronix
 

Short story on those, I had a customer with a 69S MFI that was pretty much stock with open exhaust, he vintage raced it in HSR/SVRA for years, we freshened it up and ran it on the engine dyno and sent him on his way to Watkins Glen, he had bought one of these kits to replace his points, well it was a rainy day at the Glen so he installed it and the thing started ,ran the rest of the weekend but felt down on power. When he returned we put it back on the dyno and it was down almost 20 hp, he got another kit, same results.. we put the points back in and the next 3 pulls were back to where he was before, It started ran fine no hicups but was not as good as it was, so I guess if you put it in your pickup truck or whatever you may not notice the loss and would be happy not to deal with points.
Mike Bruns

MY EXPERIENCE TOO!! Thanks for the post.

I am so tired of people trashing Pertronix. In some threads I have heard many times to just leave the points in as Porsche designed it..... Porsche would have used a Hall effect system if it existed at the time.

When people say they’ve had them in for 15 or 20 years with no issues I believe that. The thing is, 15/20 years ago they were probably made in less volume and tested to a higher standard.

There is an inherent problem with most powered sensors which is to do with low battery voltage cranking. At some voltage threshold, the sensor will power off which causes the output to switch off. The problem here is that this is ‘seen’ by the CDI box as a trigger signal.

So, when you crank an engine the battery voltage drops as the cylinder pressure rises and if this causes the voltage to fall below the threshold, the CDI box will fire. Often this is way before TDC so the engine will kick back. This typically happens when the battery is already low, making the car difficult to start.

I’m not trying to bash the product but YMMV.

I bought a pertronix 1 to fit the Ford 8 cylinder dizzy on my test rig a few years ago. It will switch cleanly down to 6V making it a good trigger for the CDI. The magnet ring is well done on this particular unit, so quality control must vary. The 6V pertronix 1 apparently won't switch below 5V which makes it marginal for use on a 6V car even if triggering a CDI. I'm really surprised at the number of people that run the Pertronix 1 in a performance application because they really do have a weak spark. Fred

The only problem I've ever had with pertronix was due to a mechanic setting the pick up wrong. It was an older unit that allowed for adjustment in distance of the pick up from the collar. They left the screw too lose and the pick up ended up making constant contact with the collar on the dizzy shaft. Wore nice groove in the pick up and killed the unit. Totally mechanic fault.

Never had an issue otherwise.

I had a pertronix fail at 1:00 am in the middle of the AZ desert on a 77 vw camper with the kids in the car. The plastic disk disintegrated and magnets stuck to the steel parts inside the distributor I dug around and found the old points and installed them and timed it with the license plate light. Only held me up for a half hour. Carried a spare disk after that but never needed it. Never should have sold that van.

2 or so years in mine still works fine. But I do keep a set of points in the glove box for when I'm in the outback... but I'm careful that way... The license plate light is clever, but my tool kit always has a test light in it.... I can eyeball the points gap close enough to get it to run on account of 40 years of practice...could probably eyeball the timing too, but that's too easy to do with the light.

I haven't had too many failures, however my complaints are with uneven cylinder-to-cylinder timing variations. I've seen as a much as 4 degrees which can spell BIG trouble if you are a little aggressive with total timing or get some substandard fuel.

Caveat Emptor if you use them.

Current Bosch QC of points is terrible so this is a conundrum. :)