Final word on spark plugs for L28

[Virto]

Hey folks -

Last time I did a plug change, I used autolite plugs, and the car ran fine, but since it's been sitting, I'm going to go ahead and change the plugs for NGK.

Now, I've seen a lot of people saying that BPR6ES is the correct plug, but NGK says that it's actually BPR5ES-11. I've also seen people say don't use the BPR model, just the BP instead.

So naturally I'm confused, and searching gets me a lot of results from people with 240s, and I'm not sure if the FI on the L28 makes a difference.

What do you use in your 280Z?

[Virto]

Well, B6ES-11 looks like the preference, after finding tidbits in some un-related threads. I may just bite the bullet and order a full tune kit from MSA, along with some new wires.

[Pomorza]

Virto

I use ngk bpr6es on my Z. They seem to run just fine. I've used NGK's since I got the car back in 09' and haven't had an issue. I also opted to use NGK wires I got off amazon a few months back, blues ones. They work quite well. For what I understand from a few sites I've been on recently the -11 type plugs are for better emissions purposes more than anything else. I don't use them personally but I don't think it'll hurt.

Hope that helps

Jan

[EuroDat]

Im using NGK BP6ES and they seem to work fine for me. The last time I had the plugs out the were a nice clean colour. This set has about 800 miles on them.

Chas

[LeonV]

Virto

I use ngk bpr6es on my Z. They seem to run just fine. I've used NGK's since I got the car back in 09' and haven't had an issue. I also opted to use NGK wires I got off amazon a few months back, blues ones. They work quite well. For what I understand from a few sites I've been on recently the -11 type plugs are for better emissions purposes more than anything else. I don't use them personally but I don't think it'll hurt.

Hope that helps

Jan

Better emissions purposes? All the -11 designation means is that the plugs are gapped to .044".

http://www.ngksparkplugs.com/techinfo/spark_plugs/partnumberkey.pdf

My '75-'76 FSM specs B6ES with a .028"-.031" gap.

[Captain Obvious]

In 75 they switched away from the projected tip to a non-projected tip plug. (They switched from the projected tipped BP6ES to the non-projected tipped B6ES.) That was in 75.

Then they switched back to the projected tip in 1980.

Here is a little non-conclusional discussion about it:

http://www.classiczcars.com/forums/electrical-s30/47495-spark-plugs-projected-tips-vs-standard.html

[Carl Beck]

As I recall - according to NGK - The Projected Tip was intended to keep the electrodes pushed farther into the combustion flame - and thus to keep the plug from fowling as easily. I would guess that with the L28E - the more precise air/fuel mixtures offered by Fuel Injection, along with the wider plug gaps ran with the electronic ignition - they didn't seem to think that the Projected Tip was necessary any longer.

Personally - if the engine has 100K+ miles, and it is ran mostly in stop/go traffic - I'd still use the Projected Tip plugs. Likewise - the "R" resister plugs help keep engine ignition noise {electrical} at bay.

FWIW,

Carl B.

[LeonV]

As I recall - according to NGK - The Projected Tip was intended to keep the electrodes pushed farther into the combustion flame - and thus to keep the plug from fowling as easily. I would guess that with the L28E - the more precise air/fuel mixtures offered by Fuel Injection, along with the wider plug gaps ran with the electronic ignition - they didn't seem to think that the Projected Tip was necessary any longer.

Personally - if the engine has 100K+ miles, and it is ran mostly in stop/go traffic - I'd still use the Projected Tip plugs. Likewise - the "R" resister plugs help keep engine ignition noise {electrical} at bay.

FWIW,

Carl B.

FYI, Nissan spec'd smaller plug gaps for the L28E.

1972 FSM: .031"-.035"

1975-76 FSM: .028"-.031"

The plug gap didn't open up until the ZX came out, but projected tip plugs were once again spec'd by Nissan at that point. I'm no spark plug engineer, but wider plug gaps have nothing to do with it. I'd imagine projected tips would be useful for both self-cleaning of the plug as well as lighting off the mixture deeper into the combustion chamber, slightly shortening flame travel.

[Captain Obvious]

Leon, it's worse than that. The gap spec for 1977-78 is .039-.043 for the US cars but Canada retained the .028-.031 spec.

For some reason, the US got a wider gap in 77 and 78 while Canada didn't?? I'm no spark engineer either, and I have no idea why...

[Zed Head]

I think that the bigger gap came when they went to a better ignition system. They got rid of the ballast resistor, changed the coil, and most likely improved the internals of the ignition module to take the higher current. This apparently gave enough juice to open the gap. A guess.

[Captain Obvious]

77 still has a ballast resistor. I don't think 78 gets one, but 77 definitely does.

[LeonV]

Leon, it's worse than that. The gap spec for 1977-78 is .039-.043 for the US cars but Canada retained the .028-.031 spec.

For some reason, the US got a wider gap in 77 and 78 while Canada didn't?? I'm no spark engineer either, and I have no idea why...

I think that's because Canadians are a little slow, ey?

I have no idea why that would be Captain, nor do I plan to put any more research into it.