NGK spark plug number

[guy_geo]

What do I need?

72 240Z, with E88 head.

Do I need to check the gap before installation?

[DatsunZsRule]

BP6ES with a .040 gap.

They should be pregapped but I always double check mine. Couple times I had 1 or two not properly gapped. Doesn't take much for them to get bumped during shipping which can mess up the gap. Also I recommend a light coat of anti-seize on the threads.

Edited April 11, 2009 by DatsunZsRule

[Arne]

I don't know about a '72, but the recommended gap for a '71 is only .032", not .040". In my experience, wider gap is not better, at least not for a 240Z.

Many NGK plugs have the gap that they preset as a suffix to the part number, in tenth of a millimeter. (1/10th mm = .004") So a BP6ES-8 has a .032" gap. a BPR6ES-11 is .044". If a plug doesn't have the suffix, assume it to be -8.

[DatsunZsRule]

I just got the info from the site linked below. I did get mine from them last time. I usually go through Nissan direct but at the time, they actually didn't have mine for my 280Z at the moment I needed them. I was happy with there service.

http://www.ngk.com/results_app.asp?AAIA=1209169

scroll down to "regular Class" plugs

Edited April 11, 2009 by DatsunZsRule

[Arne]

My info came from my Nissan FSM. Calls for 0.8-0.9mm (.031-.035"). I'll trust Nissan before I trust the plug manufacturer.

[DatsunZsRule]

No, I agree Arne. I'm the same way. I don't have a FSM for a 240Z so i just listed the one NGK showed for it on there site which I shouldn't have done. That is the right plug though.

[JonnyRock]

I just picked up two sets of NGK BP6ES-11's today. They ran about $2 apiece at NAPA. They had to order them in.

And my FSM says the same as Arne's.

Edited April 11, 2009 by JonnyRock

[sblake01]

The wider gap is for the cars with electronic ignition. The correct plug number is BP6ES for a 240Z and 260Z (.031-.035) and B6ES for a 280Z (.039-.043). Those are both according to the FSM. Apparently the EFI cars don't need the 'P' (projected tip). The 'R' (resistor) is optional. Technically speaking, Jared, if you're running BP6ES with a .040 gap on a 280Z, you're using the wrong plugs with the wrong gap.

Edited April 11, 2009 by sblake01

[guy_geo]

Super, merci beaucoup!

[240jetjoc]

While on the subject of spark plugs, what would be your plug and gap recommendation for the following motor: L28 1mm over with Mn47 head (280Z valves, unshrouded, ported/polished, etc. and appr. 11.2:1 compression), .520 lift Rebello cam, and Electromotive direct ignition system. Thanks.

[sblake01]

I'd say start with somewhere .040-.045 range. The two distributorless vehicles I have owned were .042 (Chevy HHR) and .045 (Infiniti J30). Now I know that neither of those cars have a setup like yours but that shoud put you in the ballpark.

[doradox]

BP6ES with a .040 gap.

They should be pregapped but I always double check mine. Couple times I had 1 or two not properly gapped. Doesn't take much for them to get bumped during shipping which can mess up the gap. Also I recommend a light coat of anti-seize on the threads.

You might want to rethink the anti-seize. The torque value in the FSM is assuming dry threads. Lubed threads will give a tighter joint for the same torque which causes higher stress on the threads and plug shell. It can also distort the spark plug shell, which can damage the ceramic insulator. Also it can change the heat transfer characteristics which effect the heat range.

http://www.ngksparkplugs.com/tech_support/spark_plugs/installation/index.asp?mode=nml

Steve