Jump to content
HybridZ

Spoke to the Head Engineer at NGK about L28ET Plugs..Verdict


slownrusty

Recommended Posts

Had a great chat with the head engineer at NGK today, got his private tel. no. through a good friend that knows him. He is very familiar with the L engines, having supported many race teams over the years.

 

Anyway his recommendation for the L28ET with about 250ish hp is the BPR7ES or the BPY7 (which I could not find).

 

He said the best gap setting would be 35thou.

 

Hope that helps. I bought a set and will run them in my car this weekend and will report back. Cost is $2.20 per plug at NAPA (in stock).

 

Regards - Yasin

Link to comment
Share on other sites

Guest bastaad525

I never seem to be able to find the bpr7es

 

also, I thought you had to use the bpr7es -11?

 

isn't the -11 specified for EFI injectors, that's the one with the projected tip right? thought that was better for EFI L28's.

Link to comment
Share on other sites

I have them in my car for the past week. No ping yet but I've been taking it kinda easy. I have a track day on Saturday so I guess I'll find out then if there is a difference. I used to get pinging at track events after the car heated up. This might not be such a good comparison since the weather is getting a lot cooler in the north east and I've changed the radiatior. Never the less, I'll post the results on Monday.

 

Joe

Link to comment
Share on other sites

violacleff - The NGK engineer just said that if you are running around 250hp then the BPR7ES is the one to use. Naturally a heat range 8 would be needed for higher hp applications. I might call him back and find out to what hp level the BPR7ES is good to. I was thinking about my own application, so that is why I said 250hp.

 

If your plugs are turning white, it would be advisable to gap them down, hence the 35thou recommendation.

 

Bastaad - Do not buy the BPR7ES-11, the "11" is the higher gap'ed plugs from NGK and then you would have to bend the electrode down with your hand gapper, which is not really recommended as the electrode will be tilted down. It is better to get the straight BPR7ES (or order them from NAPA). If you have no luck, I can get you a set and ship them to you. That will be my good deed for the week!

 

Yasin

Link to comment
Share on other sites

Familiar number BR8ES - I used to run those in my Yamaha RZ-500 about 15 years ago. Square-4 twin crank 2 stroke GP500 engine. I went through a LOT of plugs street-driving that thing...

I'll try a sent in the car next year.

Any fouling problems during warmup?

 

Doug

Link to comment
Share on other sites

One needs to account for the spark plug style as well as the heat range. For example, a 7 range plug with a projected core plug (the insulator nose extends beyound the plug metal housing/thread) vs a conventional one (insulator at about the same level or below the metal housing) will be different. The projected type runs a little hotter at idle and a little cooler at high speed (more fuel being sprayed on it) which can affect idle quality in a bordeline application such as BRE8 in a Z (projected core when available is better).

Also, if you change from a plug with a projecting core to a conventional core as is often on cooler plugs, you will need to advance the timing a few degrees since the the spark from the shorter plug will have a longer distance to travel. So Drax, if you already haven't you probably need to advance your timing.

Lastly a good trick is to file down the earth electrode (the one that comes of the side) so instead of extending over the whole center electrode it covers only half of center electrode and to taper the end of the earth electrode.

The shorter and tapered ground electrode will make the plug run approximately 1/2 degree cooler, so a 7 can act more like a 7.5 (according to Graham Bell).

Perhaps, more important, by reducing the amount that the earth electrode covers the center electrode and hence spark, the flame initiated by the spark can better propagate resulting in better combustion.

(when filing the earth electrode shorter and tapering the ends, keep sharp angles, since it is easier for spark to jump from a sharp edge).

Link to comment
Share on other sites

Lastly a good trick is to file down the earth electrode (the one that comes of the side) so instead of extending over the whole center electrode it covers only half of center electrode and to taper the end of the earth electrode.

The shorter and tapered ground electrode will make the plug run approximately 1/2 degree cooler' date=' so a 7 can act more like a 7.5 (according to Graham Bell).

Perhaps, more important, by reducing the amount that the earth electrode covers the center electrode and hence spark, the flame initiated by the spark can better propagate resulting in better combustion.

(when filing the earth electrode shorter and tapering the ends, keep sharp angles, since it is easier for spark to jump from a sharp edge).[/quote']

 

 

I've done this before to the regular BPR6ES-11's and had good results. Don't know why I stopped other than being lazy.

Link to comment
Share on other sites

I´ve been running BPR7ES-11 in my L28E (F54,N42) twinturbo setup.

The gap was reduced to around 1mm (.039").

 

Has worked very well for me, with somewere around 270 crankhp.

 

I´m aiming for 300+ rwhp and thinking of going to an 8 (no -11, wich by the way, stands for a gap of 1,1mm/.043")

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...