Spark plugs

[iannima]

This is a topic on which I have heard many metropolitan legends...

The typical story runs along the lines of modern spark plugs not being intended for side valve engines designed for 70 Octane petrol (which I am sure is all true ) and that all manners of woe will befall whosoever dares not to fit the original Russian ones such as these for sale with Sergey



https://retrogazparts.ru/products/20994907

Those with a DDR vehicle may find themselves equipped with DDR spark plugs such as these Isolator M18-145:



https://www.ebay.de/itm/unbenutzte-DDR- ... SwjthcNILS

I am sure our Polish; Czech and Slowack comrades will be able to provide the locally produced examples which are likely to be fitted to vehicles formerly in service with those other armies of the Warsaw Pact

[iannima]

The reality -as documented by a current discussion on the German forum- is somewhat different.

Firstly, Russian plugs are apparently notorious for the insulator shattering -God only knows why - This has happened to me at least twice if not three times :



I am now finding out on the German forum that this is very much common, and that I have been RELATIVELY lucky, because the broken ceramic can get anywhere and do all kinds of damage, e.g. stuck valves; scored cylinder bores etc.
Apparently the DDR ones are also known to do this

[iannima]

I think it will surprise no one that the Russians have been discussing this issue for some time already...

http://www.gaz69.ru/ipb/topic/126763-%D ... -%D0%BC20/

And the gist is that you actually CAN use alternatives, a list of possibilities being the following:

-Denso L14-U
-Autolite 386
-Motocraft BTS8
-Champion STK 22
-NGK AB6
-Bosch DR8BC
-NGK APR 6F-VG4
-Beru 18K-7BU

[iannima]

Last time I had to sort out the engine after a major failure (including but possibly not being caused by a broken spark plug insulator), I decided that it was time to ignore the metropolitan legends (and the purists) and try out the alternatives. I confess in my case it was very much a case of picking the ones that seemed more easily and readily available in the UK. So I went for the NGK AB6

https://www.ebay.co.uk/itm/BRAND-NEW-NG ... 1438.l2649



That was nearly three years and 3,000 Km ago. I probably should not say this but I cannot say that I have found any basis for the metropolitan legends mentioned above. My plugs are very chocolatey brown and the engine seems to be running OK.

[portamurda1]

Yeah, it’s a complete load of rubbish...a spark needs to be strong and clean

[wyvernfyre]

I run AB6 spark plugs in my Gaz 67 and they work fine

[duncan]

Had AB6 i n ours as well. Many things wrong with the vehicle, but never the plugs

[Abrs]

Yeah, had a few sets of plugs sent out FOC when I was ordering parts for the Zil a few years back, they were the same brand as the ones in the pic higher up, they didn't last long for me either, most seemed to just stop producing a spark, never noticed any broken ones though. Anyway after that I just went through the NGK reference chart and got the ones that looked the closest, used these for years without issue, upgraded from the standard plugs though to iridium plugs after fitting LPG, the only ones you can get are slightly longer than the standard plug but they work very nicely in the Zil.