pertronix coil and resistor

[john123]

I am putting a Pertronix ignition in my 1966 230 sl zf.  I would also like to replace the coil and resistor.  I see listings for several different coils and five different resistors on vendor websites.  Does anyone have information as to the best combination of coil and resistor for a Pertronix ignition in this application? The Pertronix instructions say to keep the resistor in line if one is present in the original setup.
thanks

[mdsalemi]

John,

The Pertronix doesn't use the external resistor(s); I left my resistor in place merely to use one side as an electrical tie point and to provide a somewhat authentic look. But, it's disconnected from the ignition system.
I took Pertronix' recommendation and used their Flamethrower II coil to replace the Bosch; it provides higher output voltage.

My Pertronix system is the 1864LA and my distributor is the cast-iron -050. I'm not certain if yours is the same or not. If you have the -050 it probably is.

[john123]

mdsalemi thank you for your reply.  I have the 1864LA Ignitor and the 40011 (1.5 ohm) flamethrower coil and a Bosch -- 051 cast iron distributor on my 1966 230sl.  I'm still not sure if I need to use a ballast resistor, and if I do what resistance. Can anyone give me a definitive answer.
Years ago I installed a pertronix system in my Jag. It really ran poorly. I read an article about a batch of bad flamethrower coils so I tried a new flamethrower coil  Still bad. Took it to a seasoned local mechanic and he said he didn't like the spark and replaced the flamethrower with a MSD coil. Car now runs like a champ.  I'm sure Pertronix is the right way to go, but you have to get all of the parts right or you will have poor results or possibly smoke and flames (bad thing!)

[mdsalemi]

No ballast resistor in my circuit. The only difference is, at the time I bought mine, the coil was called the Flamethrower II, and it came in only two models: chrome and black. Built in .6 ohm resistance.

I see now that there are other Flamethrower coils on the Pertronix website. I see coils with 1.5 ohm and 3.0 ohm. The coil I have is the 45011. The one you have, 40011, is the Flamethrower (not II) with 1.5 ohm. Had my setup in since 2011. No ignition issues since then.

[SEB]

Michael,
I have a question, because I just ordered for my friend  the Pertronix 1864LA - is on the way. But for sure he will face with the problem what coil resistance should be used?
Will it work with it current Bosch coil? Or he should replace it?
Many thanks in advance!
Sebastian

[lagolag]

It will work, no need to replace the coil if you have the Blue Coil, just install the Pertronix and do the timing.
It worked well on my 1967 230SL when I installed my Pertronix last summer.
Just for reference:
A friend of mine driving a classic car of other brand han the Black Bosch Coil, he was instructed to change to the Blue Bosch Coil to make it work.

[mdsalemi]

Michael,
I have a question, because I just ordered for my friend  the Pertronix 1864LA - is on the way. But for sure he will face with the problem what coil resistance should be used?

Again, I have (upon Pertronix recommendation at the time) the Flamethrower II coil, part number 45011. It was only something like USD $35. No ignition issues.

[jeblack123]

I replaced my points with Pertronix 1864LA in my 1968 280 Euro spec. I kept the Bosch coil and bypassed the resistor and car runs well with no issues for over 5 years.

James (Eddie) Black

[SEB]

Many thanks for all this inputs. Ordering the Pertronix part I have seen on their web side, that they have two parts numbers - one for the 230SL 1864LA
https://pertronixbrands.com/products/pertronix-1864la-ignitor-bosch-6-cyl?variant=31797245247524
and an other 280SL engine- the 1863 version
https://pertronixbrands.com/products/pertronix-1863-ignitor-bosch-6-cyl?variant=31797243969572.
Here on the forum that you all took the 1864LA also for the 280 engine?
Does anybody know what is the difference?

[mdsalemi]

When I search their website for 1969, Mercedes, 280SL only two models come up. 1864LA, Ignitor, and 91864LA, which is Ignitor II with adaptive dwell.

Like I’ve said before and others also said the same, I’ve got the 1864LA on an -050 distributor.

[Lew]

Will the Pertronix PELPT1864LA fit the 1971 280sl?  Their website only states 1968 and 1969....

[Benz Dr.]

Will the Pertronix PELPT1864LA fit the 1971 280sl?  Their website only states 1968 and 1969....

The CD ( capacitive discharge ) type ignition system is a type of electronic ignition and was common during those years on a number of different manufacturers. If the system is working right I would leave it alone. There is very little to be gained by going to a system that uses different parts but uses the same basic operating system which is a switching device to fire the coil.   

[Lew]

Thanks for your reply.  So, if I were to make a modification, are you saying go with the 123 distributor?

[mdsalemi]

The later model 280 SL‘s already had a Bosch electronic ignition system as I recall. I think that is what Dr. Benz is referring to. The only real challenge is if your Bosch ignition module fails, they have been unavailable for many years and if you were to find one used somebody would want a fortune for it. In the case of any kind of failure with that the 123 is a good solution.

The earlier 280SLs did not have this. I believe that’s why the Pertronix site doesn’t list the 70 and 71s as part of the fitment guide.

[Lew]

Oh, ok, think I've got it now....  Soooo much I don't know.  In the very short time I have been a member, this group is amazing.  Such a value for $30 annual dues.

[ctaylor738]

I would only add that with a 123, you are getting a brand new distributor.  With the Pertronix, you are still dealing with an old and possibly worn-out distributor wrt to timing advance and stability.  I also understand that the vacuum dashpot is NLA. 

I have worked on a number of cars with original distributors where the timing bounced around +/- 10 degrees at constant RPM.

And, with a 123, you get a new cap and rotor.

Cheers,

CAT

[mdsalemi]

I would only add that with a 123, you are getting a brand new distributor.  With the Pertronix, you are still dealing with an old and possibly worn-out distributor wrt to timing advance and stability.  I also understand that the vacuum dashpot is NLA. 

Precisely, and thanks Chuck, for driving the point home.

Prior to installing my Pertronix in 2011, I had my -051 fully rebuilt. Actually, I had two rebuilds of two -051s: one by Dan Caron, and one by Glenn Ring in NY. Alas, for some bizarre reason, the one from Dan (despite being just a stone's throw across the river from Michigan) was held up in customs for weeks. Glenn's arrived quickly without troubles at the border of course, so that's the one that was replaced. I believe I sold the other at that time.

I suspect if you have a worn distributor and you are trying to correct ignition ills by removing the points and installing ANY kind of electronic breaker less or capacitive discharge ignition system, it's a fool's errand. You need to have your distributor working properly first.