123 ignition for Datsun L6 on my L28

240L31

Club Member
I haven't checked yet. However I talked to the 123 supplier over here in Germany, seems to be a honest guy. He was quite surprised to hear about cap failures, had never heard of the before with 30+ units sold to the Datsun crowd.

Also I think the resistor inside the rotor only hurts if you run any additional MSD box or similar, doesn't it?
 

Huw

Club Member
Never had a problem with the supplied cap to be honest. Plenty of replacement caps and rotors available online. Can get replacements from various distributors in the UK or from Rockautos, I get mine from Powerspark via their eBay shop. Also not had an issue with the resistor in the rotor either.

123 has been a great bit of kit for my 280ZX, zero issues with it.
 

yellowz

Club Member
What coil do you use with your 123?

Ordered one a while back and chased up delivery today. The guy I spoke to was very helpful in trying to sell me a new coil but did not know when the dizzy was coming in! His reasoning was 'buy a new distributor - buy a new coil every time'.

I know its his job to sell stuff but he recommended a Pertronix Flame Thrower 1.5 ohm at a high price. When I looked on line on another website a. they were a lot cheaper, b. the advice about the Flame Thrower was meant for 'Fast Road or Race or the coil will overheat'. The fastest I'm planning on going is a tad over 70 (nobody sees you looking sooooo good if you go faster :cool: ), so never going to go through peak revs.

Any recommendations gratefully listened too. My knowledge in this area runs to I know what it does and when a mechanic tells me I need a new one I buy one.
 

Huw

Club Member
1.5ohm Flamethrower. Always use them in my cars. I’m sure there is better but I stick with what I know 😋
 

alienpoker

Forum User
I think Bosch is best for the cap, if it fits. Sorry to hear the new ones may not index right. I got some NOS ones and they did, although out of the two one had a hairline crack. I complained and got 1/2 my money refunded. So I only have one.

I like Beru too- I think the 123 ignition/rotors supplied are Beru.

I use WVE 4R1209 Rotors which says ‘made in Italy’ on the box. They do have the resistor though, which I removed and soldered on the one in my car. I have a few of those so hit me up on a DM if you need one, you can modify it yourself. More detail is earlier in the thread.
 

AliK

Vehicle Dating Officer
Staff member
Club Member
Never had a problem with the supplied cap to be honest. Plenty of replacement caps and rotors available online. Can get replacements from various distributors in the UK or from Rockautos, I get mine from Powerspark via their eBay shop. Also not had an issue with the resistor in the rotor either.

123 has been a great bit of kit for my 280ZX, zero issues with it.
So uncle Huw, I had two Beru caps fail on me - one was broken the day it arrived 🤣. The other was arcing on the outside.

Have been Ok with Bosch.

1.5ohm flamethrower works very well and doesn’t overheat. The late Mr F and I spoke about this a lot and he had quite a few people experiencing issues with the 3ohm one - engines struggled to Rev out in the higher range. But I can’t recall the engineering reason for it ;)
 

AliK

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alienpoker

Forum User
Hmmm… Rotors and caps.

While the Bosch GB782 may fit and be correct for the 123 ignition distributor, that crosses to a
Bosch 1.234.332.074 rotor

The part number I was given for the rotor (according to Bosch) is: Bosch 1.234.332.024
Which was superseded by part number:
Bosch 1.234.332.088
Same as Beru EVL 4/6Z (EVL46Z)

I should be clear and say both the Beru VK102 Cap (which now comes in black -as well) and the Rotor 123i sells are recommended by SNG who make the actual distributor bodies. But I’ve found the Bosch stuff more reliable over a long period of use / heat cycles.
 

240L31

Club Member
So final question, is there any evidence that the standard resistor type rotor is any bad with the recommended 1.5 ohm coil? I couldn't find any and also can't see any issue from an engineering standpoint.
 

alienpoker

Forum User
None, but you get less strong spark. You could leave it there and use the NGK BP6ES instead of the BPR6ES on a stock 240Z engine. They run great. For performance or if you are racing, you probably have an MSD 6A or other CDI ignition system: you delete the ballast resistor, modify the rotor, and run the BP6ES sparkers. R means there’s another resistance in the plug, and kills interference on mainly AM radio. I used to just add an inductance (small coil) on the input power for just the radio for suppression when I had the stock AM mono radio in my 240Z - or I’d only listen to FM. Lol. I feel old now.

There’s resistance in the plug wires too depending on the ones you use. But for cruising around on a stock 240Z you can leave everything as is. There’s a whole thread and other discussions here: https://www.classiczcars.com/topic/31474-ngk-spark-plug-number/

Other owners may know more than I do about this topic, but I have studied electronics. So YMMV.

Google is also your friend. -Richard
 
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AliK

Vehicle Dating Officer
Staff member
Club Member
So final question, is there any evidence that the standard resistor type rotor is any bad with the recommended 1.5 ohm coil? I couldn't find any and also can't see any issue from an engineering standpoint.
So, I’ve ran both with and without rotor resistor - did I notice a difference? None whatsoever!!

I even for a bit of fun added the ballast reaistor in and still didn’t notice a difference!

I’m pretty sure you will see some gains / losses on a rolling road but in normal spirited road driving, the difference was indiscernible to me.
 
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alienpoker

Forum User
From another thread:

“Flamethrower coils; there is a 3 ohm one and a 1.5 ohm one that you use with a ballast resistor.

The 3 ohm coil has an 80:1 ratio, the 1.5 ohm coil has a 100:1 ratio, therefore the output voltage of both setups is going to be more or less the same, so basically the whole argument of the 3 ohm setup putting out more volts than the 1.5 ohm setup doesn't really hold up. It looks like the manufacturer has put more secondary windings and thus a higher step-up in the 1.5 ohm coil in order to compensate for the ballast resistor.”

So provided you have the right coil, the ballast resistor can stay in a 240/260z without CDI. Same with the resistor in the rotor, if your setup has an MSD6A (CDI) then you remove the rotor resistance. Otherwise I don’t think you will need to, just run it as it comes.
 

yellowz

Club Member
So the 123 arrived today and the instructions are in German - French - Spanish................... I have read enough on the forum to go through the install with confidence, there is a lot of good info and advice to follow. Thanks to all who went before me!

While I'm doing it plan to change the plugs and leads (when I've it running). What plugs are people using for an L28, the manual has this which does not help me. I think I'm standard but what determines whether you need hot or cold? I'm thinking that is when you want to be precise with a tune?

1670960509745.png
 

toopy

Club Member
Colder plugs are to help stop pre-ignition in tuned/performance engines. Not so sure why you would need a hotter plug though, really cold operating environment perhaps?!
My L28 is standard so i use BPR6ES
 
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AliK

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I use the 7ES for the reasons the Toopster mentioned - but mine is quite modified.
 

alienpoker

Forum User
BP6RS is normal. No reason to run the resistors in the sparkers anymore that I’m aware of. No one listens to AM radio which the BP6RS was used to cut down on an RFI hum that changed with RPM. So i would recommend the NGK BP6S On an untuned / stock setup. BP5ES are so fine for a stock engine but run in a hotter range, perhaps can help to burn off residue like carbon.
 
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