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prebordao's Avatar
 
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To Pertronix or not ?

I'm thinking of replacing the points in the distributor with an Ignitor kit from Pertronix.

Apart from not having to deal with points again, what benefits (even small) can I expect ? Better cold starts ? Slightly better mileage ?

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Old 01-03-2012, 03:20 AM
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Installed the Pertronix about 10 years ago in my '74. One of the best upgrades I've made. Don't know if any improvement in starting/mileage etc. but never having to change and adjust points again is great.
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Old 01-03-2012, 05:11 AM
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I think I'll go that way too.
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Old 01-03-2012, 05:34 AM
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Old 01-03-2012, 06:25 AM
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I removed the Pertronix from all 3 of my old cars. I found every cylinder had different ignition timing; cylinders varied by 6 degrees if I remember right. Junk. Stick with points or go with a system which will give ignition pulses 60deg (120really) apart.
Going back to points was an upgrade in driveability IMO.
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Old 01-03-2012, 06:32 AM
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Can you be more specific ?
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Old 01-03-2012, 06:32 AM
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Really!! Need more data

Quote:
Originally Posted by 69911e View Post
I removed the Pertronix from all 3 of my old cars. I found every cylinder had different ignition timing; cylinders varied by 6 degrees if I remember right. Junk. Stick with points or go with a system which will give ignition pulses 60deg (120really) apart.
Going back to points was an upgrade in driveability IMO.
I have had a pertronix in my 1973 for 8 years and it is terrific. Engine runs great and never had a problem.

Give us some proof before you call this excellent product "Junk"

I totally disagree with you.

How did you measure the timing variation? I am very curious. Before I accuse you of techno babble or working for a competitor, I really would like to know how you did this measurement.

It does not add up to me. The cam in the distributor provides the triggering through the Hall effect system in the Pertronix. How is this cam off by 6 degrees? I don't get it.

Points are in proper timing for less time than they are out! Pertronix keeps system in time and needs no maintenance. They are a godsend to points cars.

Installation is easy. You only need to add switched 12vdc to power the module.

Please give us all technical specifics including the model of Pertronix you tested.
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Old 01-03-2012, 08:00 AM
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Prebordao; Find someone with a pertronix unit and take a timing light with adjustable timing dial. Connect to all 6 wires and spot using the marks on the pulley. Porsche marked for all cyl. Note the variance. Alternatively find someone with an old distributor machine to test before you install in the car. The fault with these lies in the fact the 6 magnets are of varying strength and will trigger at slightly different distances to the hall effect sensor. I swapped the magnets inside to diagnose to cause of the problem and the variance followed the specific magnets. Lead to slightly reduced power and lumpy idle.
Properly installed and lubed points on a good distributor will give years of service with the CDI system.


DICK: You must have awaken on the wrong side of the bed this morning. I will not reply to such a hostile post. You should learn people can disagree in this world....
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Old 01-03-2012, 08:28 AM
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"The cam in the distributor provides the triggering through the Hall effect system in the Pertronix."

Which has the reliability problem of the Hall Effect semiconductor being in a high
temperature environment. With the Bosch CDI system, the ignition points only
switch a very low current and the points basically last forever. So there's no
real benefit to using the Pertronix and a downside because of the reliability
issue, i.e. another ignition element that can fail.
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Old 01-03-2012, 08:38 AM
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Pertronix

I have had issues with these from street cars to vintage 2.0 race cars that run as single plug, from starting up and running sounding fine but will not load on the engine dyno period that was a stock 69 "S" ! ended up putting the points back in and it performed as it should, retested pertronix again same issue, another customer installed them in his FIA 2.0 car at an event at the Glen and it seemed "Flat" all weekend, we put it back on the dyno when he returned and it was down almost 15 HP, reinstalled points and power came back, I am not a fan of points by any means because of the constant attention they need but that is not good to see that . Just my 2 cents

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Old 01-03-2012, 08:41 AM
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I am another satisfied user of the Pertronix, but I can certainly understand that the accuracy of the cylinder-to-cylinder timing is dependent on the accuracy of the location and strength of the individual magnets imbeded in the spinning magnet cap, as well as the temperature of the Hall Effect transducer. That being said, Pertronix must know this, too, and their production process specs must control these variables to an acceptable degree (no pun). It would be helpful if Pertronix shared these specs.
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Old 01-03-2012, 09:09 AM
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I've never owned a Porsche with points, however, I have replaced points with Pertronix ignitor on several other vehicles with outstanding results. For what it's worth.
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Old 01-03-2012, 09:15 AM
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Think I'll wait...
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Old 01-03-2012, 09:24 AM
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I think calling a product "junk" is pretty hostile! Especially with no supporting data in the post.

I plan to test my Pertronix to see if I can duplicate your results.

"Properly installed and lubed points on a good distributor will give years of service with the CDI system." I never found this to be true. Properly installed and lubed my 2.7 would be off song in 7000 miles or less. Points don't give years of trouble free service.......unless you rack up few miles.
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Old 01-03-2012, 09:55 AM
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"Properly installed and lubed my 2.7 would be off song in 7000 miles or less."

Very negligible, and not worth changing to add another ignition element that
could/will fail! The device not only has the Hall device but a power switching
transistor (and other parts) used to drive a coil, e.g. Bosch blue, directly.
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Old 01-03-2012, 10:18 AM
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I don't want to add fire to this... but every modern car that we drive has thousands of transistors (inside IC's of course) and other components. It's true that sometimes they fail, but fortunately it is quite rare.
I don't think that adding 3-4 additional components to our early cars would detract significantly from their reliability. And the CDI already has a few components, so we're not starting from 0.

Just my 2
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Old 01-03-2012, 10:25 AM
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Crane Optical Trigger is a better choice in my opinion.

However, the position of the optical window can be a concern with individual timing. This can be adjusted out quite easily should you desire tuning to the nth degree. I did.

The system works on a simple LED and photodiode. extremely reliable.
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Old 01-03-2012, 10:45 AM
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Quote:
Originally Posted by Lorenfb View Post
"Properly installed and lubed my 2.7 would be off song in 7000 miles or less."

Very negligible, and not worth changing to add another ignition element that
could/will fail! The device not only has the Hall device but a power switching
transistor (and other parts) used to drive a coil, e.g. Bosch blue, directly.
I found the timing change more than negligible. I could really sense it.

I found it well worthwhile adding and another device, and the failure rate for me is "0".

I have had no problems in 8 years and carry a set of points in just in case. You could carry a spare Petronix for as little as they cost!
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00 Saab 95 Aero wagon stick
01 Saab 95 Aero wagon auto
03 Boxster
90 Chevy PU Prerunner....1990
Old 01-03-2012, 11:03 AM
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Quote:
Originally Posted by Lorenfb View Post
"The cam in the distributor provides the triggering through the Hall effect system in the Pertronix."

Which has the reliability problem of the Hall Effect semiconductor being in a high
temperature environment. With the Bosch CDI system, the ignition points only
switch a very low current and the points basically last forever. So there's no
real benefit to using the Pertronix and a downside because of the reliability
issue, i.e. another ignition element that can fail.
Does this mean the block that rubs on the cam never wears? That is where the problem comes in. Not the points burning.

Believe me the dwell changes as the rubbing bock wears, which changes timing. If the dwell goes to "0" to car stops running. I have had points do that on my 911 years ago.

I am not really trying to be argumentative, Just that my personal experience in driving a 1973 Porsche with and without points for over 130,000 miles is that points basically DO NOT last forever.

The upside to a Pertronix conversion is no maintenance. The upside is no reliability issues.

All of this in my multi-year and 100,000+ mile experience.
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01 Saab 95 Aero wagon auto
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90 Chevy PU Prerunner....1990

Last edited by dicklague; 01-03-2012 at 02:37 PM..
Old 01-03-2012, 11:37 AM
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"I don't think that adding 3-4 additional components to our early cars would detract significantly from their reliability. And the CDI already has a few components, so we're not starting from 0."

Yes, but NOT inside of a hot engine part (distributor) and exposed to 30KV - 40KV
of high voltage. That's why Porsche on the later 911SC used a magnetic pickup
in the distributor, i.e. just a simple coil of wire without any temperature problems.
Remember, most all commercial semiconductors are only rated at 70C max, and
much more than that is common for an air cooled engine. Many of the newer engines
with cam position sensors (Hall Effect) have high failure rates versus the magnetic
pickups of the RPM sensors.

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Old 01-03-2012, 07:05 PM
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