Correct Twin Cam Coil On Plug Spark Plug Type Is>

[RB30-POWER]

Hey Guys and Gals.

Just thought I would make this thread as its become apparent to me alot of people use the BCP plugs in their RB engines with coil on plug spark systems.

The correct plug to suit the engine and coil arrangment is actually the BK type plug.

So for example, you should use BKR6ES-11 instead of BCPR6ES-11 in standard copper type plugs, PFR6G-11 for Platinum type plugs and BKR6EIX-11 for Iridium.

The BK type meet the "ISO" standard and are designed for the coils that go over the top of the plug, the BCP type meet the "JIS" are designed for speak plug leads.

The difference is the BK type are 2.5mm shorter and if you use the BCP type the spring in the coil can be damaged or compressed, so that if you go back to the correct plug, it doesn't make correct contact and cause possible missfire.

I know alot of you will say, yeah yeah, I use BCP without dramas, but fact is that type is not designed for coil on plug ignition systems.

Just thought i would make this thread so all owners are aware of what might not otherwise be apparent.

Edited May 19, 2007 by RB30-POWER

[Cubes]

I checked the height issue out some time ago when I had a set of BKR plugs.

There really is nothing to worry about with our coil on plug setups as there is more than enough coil travel not to cause problems with bind. Running BCPR plugs for quite a few years and comparing my springs to another coil that had its life sitting on a plat plug there was no difference in coil height. So they don't squash so to speak.

So I wouldn't be too concerned with the remote ignitor coil setup we use. I haven't checked the s2 r33's or r34's so that may very well be a different story.

[BHDave]

Thats because bcp's are specified for 20's and 26's. I agree that bkr's are specified for 25's though.

[Cubes]

There's no difference between the S1 Rb25's coils and the RB20/26's coils.

[govich]

I wouldn't say it's a cause for concern. I don't see how the spring could be damaged. Having said that i've always used BKR6E-11 plugs myself (RB25).

Edited May 21, 2007 by govich

[Cubes]

One would think according to.......

http://www.ngk.com/sparkplug411.asp?kw=JIS&mfid=1

JIS (Japanese International Standard) plug height is 53mm (i.e the BCP range)

ISO (International Standard Organisation) plug height is 50.5mm (i.e the BKR range)

Nissan made in Japan... You'd think they would adopt the JIS standard plug.

And then according to this..

http://www.spark-plugs.co.uk/pages/technic..._faq.htm#ISOJIS

While the small difference in height will not affect most vehicles (ISO and JIS types can often be interchanged), some vehicles (particularly with direct fire ignition or specially fitted plug caps) MUST use the correct plug standard or a bad contact between plug and cap may be result.

I see that as suggesting; if the coil on plug vehicle has been designed for use with the larger JIS (BCPR) plug then using the smaller ISO (BKR) plug 'may' cause poor contact.

Possibly why some have had their springs and spring seat within the coil show signs of corrosion/burns? :S

Considering the amount of km's my coils did (200,000+) the springs and spring seats were perfect with the slightly taller plugs.

[BHDave]

There's no difference between the S1 Rb25's coils and the RB20/26's coils.

That too! which is another reason why i find it weird that the 25 got different plugs specified. Could it be something silly like NGK didn't have the bkr's in the late 80's when the 20 and 26 were born but they were around in 93/94?

What do r33/34 gtr's get factory?

[govich]

Could it be something silly like NGK didn't have the bkr's in the late 80's when the 20 and 26 were born but they were around in 93/94?

You could be onto something Dave. The BKR series are a really common plug nowadays. It could well be that Nissan wanted to conform with newly introduced ISO stuff with the newer engine. Sounds feasible to me..

[2rismo]

BCPR plugs work fine in everything RB. What's the problem?