Is there any real difference between NGK BPR6ES-11 and BP6ES-11?


My 240z has a petronix ignitor installed and sometimes gives me hassles with the current BP6ES which advertise as pre-gapped.


Have called many retailers here in Panama and they only have either BP6ES or BPR6ES-11. They dont have BP6ES-11.


Can i use NGK BPR6ES-11? US$1.80 a piece!

The R's are the resistor plug version. Used to supress radio interference.  Mostly AM radio were sensitive to the ignition noise.

B6ES is fine, and they are the cheapest.

 

You don't need the P and R letters. I find the R ( Resistor ) plugs don't run fine on older engines.

I use the B6ES also on my 240Z, works great. The plugs are pre gapped from the factory, I believe 0.8 don't need to do anything on that, just instal them from the box.

Edited April 1, 20159 yr by bartsscooterservice

http://www.classiczcars.com/topic/31474-ngk-spark-plug-number/

 

Read post #3

My car has a Pertronix ignitor! Maybe the BP6ES are giving me hassle? Could this be correct?

bp6es is fine.

Adjust your jets so that all plugs look like this after a 5min run on the highway up to Colón at 130km/hr

Pull over every 5 min and adjust jets until you get close like this:

or [brand new plug]

or

Edited April 2, 20159 yr by Blue

BP6ES are good plugs for a stock setup. Gap them to about .03. Don't go past timing of 32 degrees at full advance (over 4000 rpm).

The following is just my opinion but is backed by Dr Jacob's book as I remember:

Plug gap should be set based on the performance of your ignition system and particularly the output of your coil. A weak coil may require a plug gap as tight as .025 while a strong coil can jump a gap of.040 or greater. The spark likes to jump from sharp edges to other sharp edges which are provided by new plugs or closely maintained plugs. Large gaps work well with high output coils and MSDs as this allows for the large spark to better address the air fuel mixture. A week coil or an over rich mixture or oily cylinder needs a smaller gap just to allow for a spark to make the jump and prevent missing and fouling.

As far as P or protruded plugs such as BP6ES go, the plug tip sticks further into the cylinder than a non protruded plug and can aid in better exposure to the air fuel mixture. This can help provide a cleaner burn with less fouling but it often depends on the head and piston design.

This is where it gets weird. When you start modifying your engine for more power such as increasing compression and air/fuel flow, other factors come into play. Protruded plugs can interfere with the piston and can also handle less total timing advance. I've raced the 240Z for over 30 years and have found this(off the top of my head) to work out.

Stock engine - BP6ES at 32 degrees full advance, .030 gap(.025 with weak coil)

10:1 ITS race motor - B8ES at 34 degrees full advance, .040 gap, MSD/Jacobs

12:1 EP race motor - same as ITS or even as cold as B9ES. Warning! I index my plugs with washers to make sure the plug electrodes will not contact the piston.

I never ever use R or resistance plugs such as BPR6ES. If you are hoping to drop the voltage through your ignition system by doing it with the plug, you are forgetting about all the interference caused by the low resistance coil and plug wires. You can even be jamming your own ignition system as I finally discovered years ago. The proper way to lower the electro magnetic interference(EMI), is to use a resistance coil wire and zero resistance plug wires. The coil wire I use is 900 ohms per foot at about 2.5 feet long(coil mounted on other side). This lowers all the voltages just the right amount to avoid inteference in my application and does it evenly across all six plug wires and plugs.

I hope this helps. This was done from an I Pad in a hotel room from memory but is very close.