Spark plugs 2012

[elansprint71]

Having checked the archive, it looks like the last time there was a meaningful discussion on this elementary subject was the Paul Adamson thread from 2001.
So; tecchnology having moved on somewhat since the manual was written, what is the considered opinion of the assembled experts? I am asking about road car spec; btw

[lotocone]

Pete,

This thread is pretty good. It includes some interesting comments from Rohan.

elan-f14/plug-advice-please-t17686.html

[elansprint71]

Thanks for responding and, having been around here for some while, I'm unlikely to go into bat against Rohan on racing tech-stuff, he know his onions but.... your linked thread is a few years old and really reached no conclusion.
Have there been no developments recently in spark-plug technology, given the changes to "petroleum" between the "five star era" (when the Twin_Cam was conceived), to the E 10 world, which we are immediately facing?

[rgh0]

As i posted somewhere more recently most of the plug development work in the last 40 years has been around extension of plug life driven by emissions regulations.

Better fuel formulations that burn cleaner, better oil control with inproved rings and elimination of lead and introduction of fuel injection has meant that a plug can last a long time and its life is really limited by the life of the electrodes. So fancy exoctic material electrodes and multiple electrode design are more common.

Unfortunately in a twin cam unless you rebuild it to modern standards and add modern fuel injection you will not get a longer plug life with the exotic plugs as the plugs in a twin cam normally fails from fouling and not from electrode erosion.

So for road use today I would stick with a standard NGK BP6ES unless you are building a modernised engine in which case you could try the platinum tipped equivalent if you do enough miles to justify its longer life but much higher cost

cheers
Rohan

[ardee_selby]

As i posted somewhere more recently... Rohan

April 2012: elan-f14/spark-plugs-t25031.html

Richard

[elansprint71]

Thanks folks; I'll get some NGK, as suggested by Rohan.

Where can I get a copy of the ardee_selby forum search engine?

I seem to be like most folks in being unable to find what I'm looking for easily. I suspect pilot error is contributing factor in my case.

[lotocone]

So for road use today I would stick with a standard NGK BP6ES unless you are building a modernised engine in which case you could try the platinum tipped equivalent if you do enough miles to justify its longer life but much higher cost

Rohan

I agree about the NGK BP6ES plugs. They have worked well for me. Last summer I installed the iridium version (NGK BPR6EIX) and within a few months the engine misfired a lot. Don't know what the problem was. I'll stay with the BP6ES plugs at only about $2 each.

[AHM]

It is all about flame kernel formation, and flame front propagation..... you aint going to notice the difference between the cheap and expensive ones!