Plug leads 1k or 5K Ohm ?

[alpina]

Recently I have had a spark plug lead end cap go bad resulting in a misfire. I replace the faulty end cap with
Another of the same resistance (5k Ohm) the car runs well with these.

However after reading posts here, it suggests they should be 1K Ohm. Authentic classics and Neimoller sell 1K Ohm sets.
I have order a set of the 1K Ohm leads to try.

So does it matter which leads I use?  What difference if any would I see?
I am currently running a 1-2-3 distributor, NGK BP6ES plugs (gapped at 0.9mm)

I would like to hear your thoughts.

[WRe]

Hi,
1 kOhm plugs (= spark plug connectors/ends) are correct.
I am also running 1-2-3 ignition with NGK BP7ES, gapped 0.8mm; see att. pic. from the NGK web site*.
...WRe

* https://www.ngk.de/nc/en/product-finder/produktfinder/PKW/ZK_BENZINER/MERCEDES/280%20SL%20%20%20PAGODE%20%20%20%20%28113%29/BP7ES/8019/

[alpina]

it is the ignition leads that i am questioning. Not the spark plugs.

[Benz Dr.]

The plugs you're using are very cold. I use BP5ES  The book calls for BP6ES but I find they don't warm up fast enough to prevent fouling when starting from cold. Make sure your coil wire doesn't have a carbon filament.

[Cees Klumper]

If I'm not mistaken the leads are not supposed to have any resistance. Only the ends. The leads should be copper core also?

[WRe]

Hi alpinaltd,
this is not the question. The question is: Which type of ignition cables should be used?

There are - more or less - 3 types of cables:
- Ignition cables with a copper core: Ignition cables with a copper core are not equipped with their own interference suppression resistor. Instead, the resistor is integrated in the spark plug connector and coil connector in the form of a conductive glass seal. Depending on the cable it is between 1 and 6.5 kΩ.
- Ignition cables with carbon resistor: For carbon resistor ignition cables, the interference suppression resistance is calculated from:
1 m cable ≙ 10 kΩ - 23 kΩ.
- Ignition cables with inductive resistor: One meter of this type of cable can have interference suppression of 2.2 kΩ to 8 kΩ.
Source: https://www.ngk.de/en/sales/products-and-assortments/ignition-cables/

The answer: See https://www.sl113.org/wiki/Electrical/SparkPlugWires. --> Ignition cables with a copper core, as Benz Dr. mentioned.

Btw, there have been two different ends: Beru bakelit with 1kΩ and Bosch metal with 5kΩ, both should work.
...WRe

[ja17]

If you are still using the stock non-transistorized ignition and stock coil do not go above 1K ohm spark plug connectors. If you have the factory transistorized ignition, or have upgraded your ignition system with a higher out-put coil, then you should be fine with 1K or 5k ohm.  To be safe do not use carbon wires or resistor plugs with either. 

[alpina]

Well I thought this was a straight forward question. I know not to use carbon wires or resistor plugs.

I’m talking about the ends of the ignition wires that connect with the spark plugs.
SLS only sell ignition wire sets with 5K Ohm ends. Others for example Neimoller and Authentic Classics
Sell wire sets with 1K Ohm ends.

I have been using the SLS set with 1-2-3 Distributor and up rated coil.  This ran perfectly until one end went
Bad. Replaced the bad end with another 5K Ohm end. And all is perfect again.
It was only because I needed to replace an end, the question arose. Should I be using a set with 1K Ohm ends ?
And if I did would I notice any difference, or is there any benefit from using 1K Ohm ends.

All the wire sets for the suppliers above are copper core.

[Tyler S]

5k ohm plug ends started showing up during the 250sl range. They were part of the "Radio interference suppression" option. If your car came with a factory radio or interference supression code on the data card then they were originally 5k ohm ends. Since you have an upgraded coil, it is even less of an issue.

[alpina]

Given my set up with the 1-2-3 Distributor with upgraded coil. Is it okay / safe to use my new set of
Ignition leads with 1K Ohm ends ?

1. Should it run better ?
2. Will there be any noticeable difference ?
3. will they produce a better spark with less resistance ?
4. Should stick with the 5K Ohm set, seeing it is running perfectly.

[ja17]

Yes, the 5k should be fine for you.

[alpina]

I have a new set of 1K Ohm. I just felt like I should give them a try. I wanted some
Reassurance that I’m not going to cause any problems using the 1K.

[ja17]

You can't go wrong with the 1K