Bosch or NGK

[Jkalplus1]

Gents,

I read the archives and was unable to find any strong opinion as to whether get the Bosch or NGK plugs of equivalent rating for optimal performance, reliability, etc.  I understand availability issues of the Bosch plugs.  I am debating getting either NGK BP5ES or Bosch W9DC.  I can easily acquire either.  I read the archives and it seems NGK is a little more in favor (Mike S. I think wrote they were less prone to fouling than the equivalent Bosch).

So it seems to me that beyond "looking authentic" there is no advantage in getting the Bosch plugs? I have a Pertronix and red Bosch coil installed right now with W7DC plugs on a 3000km rebuilt engine.

Thanks for your enlightened advice.

Jerome

[Ulf]

Have run with both over the past 4 years with no perceived difference whatsoever - however, one NKG plug gave up in this period while I've never had a Bosch one fail, could be coincidence though...

[Benz Dr.]

I'm unable to find Bosch W9DC so I went to BP5ES. The W7DC is a bit too cold for most applications even though every book will tell you that's one to use. Those application guides were developed a long time ago with different fuel blends so I use them more for spark plug type rather than heat range.

[Jkalplus1]

Hi Dan,

I found new W9DC for sale on Kijiji, and there is also a British supplier who has them.  Not overly hard to get with an internet search.  I was only wondering, if you were putting plugs in your personal car today and you had 6x BP5ES and 6x W9DC on a table in front of you, would you put the Bosch or the NGKs in your car?  Or, like Ulf says, is the difference unnoticeable?  I am inclined to think like Ulf and "an equivalent plug is an equivalent, which means it is just the same", but I lack the experience in the field to make that call.

[philmas]

Non resistor plugs such as Bosch W7 are NLA in many places, unless you order them from the web...
NGK can be found much more easily, at least in France.That's why I 've been usig them for 2 years by now, with great satisfaction.

[Richard Madison]

My car spends time in city traffic at modest speeds so some fouling is to be expected.

I have used the Bosch W7 and also the hotter W9 Bosch plug.

While at a PUB event, I switched to NGK BP6ES then later to the hotter NGK BP5ES.

I don't see any real difference in performance with any of these plugs.
Perhaps the hotter plugs take a little longer to foul but I don't keep accurate records to know this.

Fouling is usually one or two plugs possibly because of worn piston rings.

I just replace the bad ones and either get new ones or have the fouled plugs blasted clean.

Richard M, NYC

[Jkalplus1]

OK, thanks a lot!

I pulled the plugs for the first time yesterday to inspect them (they had the appropriate light brown color), and realized they were W6DC, gapped at 29 thousandths.  I have a set of BP5ES in hand, I will gap them at 35 thousandths and try them.

[Run MBC]

Temped to try NKG Iridium BCPR5EIX-11, had good luck with Iridium plugs in my Lexus.  (Used to run Bosch Platinum.)

[Benz Dr.]

I have quite a few platinum plugs that were removed from poorly runing engines. These plugs are resistor type which won't work as well as non resistors since the spark plug ends already have them.
The main focus on a 113 ignition system is that you need to match all of the parts so that you have a complete system that works in harmony. Extra resistors. wrong spark plugs, carbon core wires, mismatched distributors and throttle valves; everything matters. Get it right and your engine will run well. Get it wrong, and you will be missing out.

[troctime]

Hi,

I just try not do do it wrong and you seems to know alot on it.
I run my 230SL from 66 since 4 years now.
I do have 123Ignition system with Valeo coil ( sold for equivalent to Bosch red coil) set of new silicon wire since two years now, running fine since 10000km.
I had my car stopped this week-end. After one hour drive without problem I feld like the car had misfires. I stopped to full tank and could not start it again !
I checked for fuel pump and fuel arriving to the injection , was ok
Then I checked for spark fire, there was no spark.
I removed and cleaned the distributor cap ... and could start again. Running fine but having difficulties to start.
As I'm going on a trip in a week, I try to make evrything fine before.
I ordered a new cap and rotor that I will install this afternoon, I think it will solve my problem.
By the way I will order a genuine Bosch red coil ( as spare ).
I want also to renew the sprark with the best for my configuration.
I have 6 x NKG BP7ES that are my spare sparks bought 2 years ago in case.
But I also bought a few month ago 6 x NGK BP8EIX, please don't ask how I came to this ref for my pagoda, I'm sure I had a good reason but I can not find it anymore.
Are this spark correct for our car ? or should I stay for the more regular BP7ES ?

Thank you for your knowledge,

Olivier

[66andBlue]

... set of new silicon wire since two years now, running fine since 10000km. .....

If you search this site you'll find many reports where these silicon wires created problems.
You should replace all ignition wires with 7mm copper core wire.
More here for example: http://www.sl113.org/forums/index.php?topic=20826
and here: http://www.sl113.org/wiki/Electrical/SparkPlugWires