Racing Spark Plug

[MPittma100]

Have not seen these before. Anyone had any experience with them?

http://www.amazon.com/PERFORMANCE-YA...=yamaha+xs1100

[CaptonZap]

Have not seen these before. Anyone had any experience with them?

http://www.amazon.com/PERFORMANCE-YA...=yamaha+xs1100

Save your money, or promise to give us a complete description of your experience with them.
It looks like variation of the surface igniters used in jet engines, which work in jet engines, but have problems with engines that can run rich, (carbon up), and don't have 75,000 volt coils.
YMMV
CZ

[MPittma100]

Racing Plugs

Save your money, or promise to give us a complete description of your experience with them.
It looks like variation of the surface igniters used in jet engines, which work in jet engines, but have problems with engines that can run rich, (carbon up), and don't have 75,000 volt coils.
YMMV
CZ

Actually, I am not considering trying them. I'm guessing that they are intended for use in applications above and beyond normal street driving/riding. I would like to hear from someone that has witnessed their performance.

Mike

[rover]

Racing plugs

Last time I changed my plugs, I did a "surface gap" on them. You trim the ground electrode so that you can rebend it to sit about .040 from the center electrode. That way, the spark is fully exposed to the incoming fuel charge. I don't have a dyno, but I can feel the smoother response and a bit faster and smoother idle. By the "feel of the pants" dyno, there is a significant improvement. My last plugs looked pretty good after I guess 5 or so years, so these should last quite a long time. I ONLY use NKG plugs.

[Prothec]

I'd like to try side-gapping my plugs one of these days... I've heard the plug life is dramatically reduced, though.

[rover]

Side gap

After 5 or more years, my original plugs looked like almost new, just some tan color to the insulators. I had a new set on hand, and I had just read about the side gapping on a race car site, so I thought I'd try it. I realize that after almost 60 years of motorcycling and trying for the best performance, the mind sometimes stretches the improvements we try, but I gained about 200 RPM at idle, and a smoother idle. No stumbling flat spots anywhere in the RPM range, and what feels like better acceleration. My engine does not burn oil, gets around 42 MPG, has 87K miles, plugs last a very long time. I am not really concerned with shortened plug life, I love the feel of a smooth, powerful bike under me. When we get our usual January thaw, I will pull those plugs and see how they held up. The way it ran all last summer, I would gladly change plugs every year, but I think they will last one or two more years. I put on about 10,000 last summer, my son is now old enough to ride with me, and I do not work in the summer, so we ride a lot. I will report back when it gets a bit warmer here.

[Crusty Snippets]

Amazing

Says you get a 3% gain in HP, and a 15% gain in acceleration.
Would like to know how they worked those numbers.
Sticking with NGK. The standard number 6 plug is a fairly hot plug, using the heat range to describe hot. Not as in hot rod or more power.
For racing purposes a colder plug would be required due to the engine running at mostly WOT and much hotter. A hot heat range plug would result in a seizure of a two stroke and likely in a four stroke motor.
We would start the 250cc 2 strokes on a 6, 7, or 8 plug until warmed up. Then switch to a 10, 11, or 12 plug for actual racing. The above dependent on how rich or lean we were running, the outside temperature, the grace of God and cloud cover. The 4 stroke motors could run a hotter plug and not seize.
If you want a more efficient spark, then more zap and more control over the advance system is obtained by more modern ignition systems.
I have electronic ignition on my 41 Ford tractor. I ran a magneto on the Norton because we only ran it to 7500, and we saved the weight of a battery.
For me the plug decision revolves around resistor plugs or not.
On an scope the resistor plug has a shorter more radical zap. A non resistor has a slower more subdued zap. The former might work better with regular gas, the other with higher octane gas. The octane burn rate was discussed in another thread.
That extra gap plan sounds interesting.
Unkle Crusty

[MPittma100]

Spark Plugs

I use Autolite racing plugs in two drag race cars. The ground electrode on these plugs are already shortened - by Autolite. So, undoubtedly, there is something to the theory of that adjustment. Another theory is to "index" the plugs. There are two reasons to do this: 1) is to have the gap turned in such a way that it will not hit the piston (in ultra high compression engines) 2) is to have the gap turned towards the incoming air/fuel charge (intake valve) for more complete combustion seemingly making for horse power.

Mike