Hi all,

 

I think I may have found an equivalent to PFR6B-11B which ceased production some years ago. Unfortunately I'm having difficulty getting the original specifications of PFR6B-11B so would appreciate some help if anyone has an old/new PFR6B-11B lying around. Even better would be if someone could send me a used plug. Why NGK stopped making this plug is a mystery.

 

I need a measurement of the total thread length from the base of the metal shell (not the gasket) to the end of the shell (not the end of the thread). Also a measurement from the end of the shell to the outside of the ground electrode.

 

The plug I'm thinking of is available in standard copper and also extreme longlife Iridium/platinum mix.

 

Any help appreciated as ever.

 

Best regards,

 

RobH

Rob can you share a little info between copper and iridium plugs,I use the HKS and find them very good but I have been reading that the US seem to favour the copper ones.

Hi Ian,

 

Concensus of opinion is that a shiny new copper plug is difficult to beat. Problem is that copper plugs wear so quickly, ignition performance soon fades. I don't cover much distance in my Z at the moment but even so I wouldn't like to change the plugs every 2000 miles. Iridium plugs *should* theoretically perform better assuming they are a suitable design for the engine/combustion chamber - there is currently no 'perfect' design of Iridium plug (or copper for that matter) for the VG30DETT - that's what I'm currently investigating.

 

Either BKR6EIX or Denso IK20 will be a good equivalent replacement for the PFR6B-11 in an NA and offer a compromise for the PFR6B-11C for the TT (cheaper, long service life and should perform approximately as well as the platinum plug). Iridium plugs are most useful for tuned engines where a colder heat range is required, it may be preferable to use a less projected plug than PFR6B-11C in this case to afford the firing tip some projection - BKR7EIX (BKR7EIX-11 if you're confident in your ignition system) or IK22.

 

It's impossible to prove anything on a dyno - conditions of climate and engine temperature etc vary so much from run to run.

 

Sorry....didn't mean to waffle.

 

BR

 

RobH

Copper plugs also give the ultimate pritection against detonation - you'll melt the electrode LONG before you go putting any holes in anything else ;)

Rob, when I spoke to NGK technical they said the only match was in an 8 heat range and was a racing plug part Rxxxx. I'll see if I can find the number.

Worth checking ZFR7F-11 coppers, they're pretty close projection wise.

Agreed to both. My only gripe with the ZFR7F-11's is that they aren't 'shrouded' as the PFR6B-11B's are. The insulator (and electrode) are fully exposed to the combustion process - pieces have been known to break off the ceramic insulator under harsh conditions. I'm expecting this 'new' plug I've found to have the same projection as ZFR7F-11 but also to be shrouded like the PFR6B-11B ;-) ++++ the Iridium version should last 120000 miles :-O

 

John - I think you mentioed it was a surface discharge type previously (the NGK race plug), excellent for extreme conditions and preventing fouling but non projected.

 

Cheers all!

 

H

Copper plugs also give the ultimate pritection against detonation - you'll melt the electrode LONG before you go putting any holes in anything else ;)

 

 

sorry, but i strongly disagree with this.

 

before platinum plugs were available people still got holed pistons due to det on copper plugs!!

 

i wouldnt rely on a plug to stop damage from det. (IMOHFO ;) )

By the way PFR6B-11B are still available in the US :confused:

 

 

There is a theory you need the projection in higher boost cars due to the extra turbulence in the chamber, btw copper plugs are meant to give a rounder spark, more suitable to turbo applications!

 

Have I been here before :shock:

Hi all,

 

I think I may have found an equivalent to PFR6B-11B which ceased production some years ago. Unfortunately I'm having difficulty getting the original specifications of PFR6B-11B so would appreciate some help if anyone has an old/new PFR6B-11B lying around. Even better would be if someone could send me a used plug. Why NGK stopped making this plug is a mystery.

 

I need a measurement of the total thread length from the base of the metal shell (not the gasket) to the end of the shell (not the end of the thread). Also a measurement from the end of the shell to the outside of the ground electrode.

 

The plug I'm thinking of is available in standard copper and also extreme longlife Iridium/platinum mix.

 

Any help appreciated as ever.

 

Best regards,

 

RobH

 

Rob,

 

I ordered a box of these (10) from the Motorbike shop where my brother works - they're an NGK dealer amongst other makes, and there was no problem getting them.

 

Shall I ask him for a quote on another?

 

Simon.

Hi Ian,

 

Concensus of opinion is that a shiny new copper plug is difficult to beat. Problem is that copper plugs wear so quickly, ignition performance soon fades. I don't cover much distance in my Z at the moment but even so I wouldn't like to change the plugs every 2000 miles. Iridium plugs *should* theoretically perform better assuming they are a suitable design for the engine/combustion chamber - there is currently no 'perfect' design of Iridium plug (or copper for that matter) for the VG30DETT - that's what I'm currently investigating.

 

Either BKR6EIX or Denso IK20 will be a good equivalent replacement for the PFR6B-11 in an NA and offer a compromise for the PFR6B-11C for the TT (cheaper, long service life and should perform approximately as well as the platinum plug). Iridium plugs are most useful for tuned engines where a colder heat range is required, it may be preferable to use a less projected plug than PFR6B-11C in this case to afford the firing tip some projection - BKR7EIX (BKR7EIX-11 if you're confident in your ignition system) or IK22.

 

It's impossible to prove anything on a dyno - conditions of climate and engine temperature etc vary so much from run to run.

 

Sorry....didn't mean to waffle.

 

BR

 

RobH

 

 

Thanks Rob :bow: you are the ONLY one I listen too when it comes to plugs.

LOL - I think we all have to agree to disagree on what works best. I s'pose if a particular plug works for you then don't change it.

 

My US suppliers report PFR6B-11B as no longer in production - I would imagine it wasn't a particularly popular plug as it isn't recommended for any other engine (as the PFR6B-11C isn't). There may still be some shelf stock here and there.

 

Projection of the spark is good for any engine but exposure of the firing end is not good in a turbo engine. PFR6B-11B allegedly gets the spark position right and keeps the insulator and centre electrode shrouded (i.e. protected).

 

Bah - I only posted to try get some dimensions :-( LOL!

 

Ciao!

Oops! It appears that PFR6B-11B should still be available from NGK in the US. It just seems that my suppliers are no longer stocking it.

 

Cheers!

Rob, it the other plug you're talking about available in other heat ranges?

Hi John, as far as I know it's a '6' (Denso 20) only BUT it is 'shrouded' like PFR6B-11B which should give the effect of running slightly cooler.

Cheers, I guess I'll stick with the coppers for now then ....