Suzuki GSX-R 600 K4 Iridium Spark Plugs

Hi,

I've heard and see, some motorcycles have Iridium Spark Plugs, and
they last longer than the normal ones i use in my GSX_R600 K4, can i
start using then also on my bike.

The recommend plugs last for 12000 km's, how many km's or miles the
iridium will last.

thanks
Jaime
Portugal

 

Google is your friend, Jaime.

http://www.densoiridium.com/faq.php

"DENSO Iridium Power plugs, with their .4mm center electrode, have
been developed for performance applications. Because gradual wear will
'round-off' firing points over time, the concentrated firing power and
voltage requirement benefits will be reduced. For this reason, DENSO
advises replacement after 30,000 miles."

That's 48,000 km between spark plug changes.

But, consider the cost of iridium spark plugs compared to standard
spark plugs. A set of iridium spark plugs will cost me
four times what a set of standard spark plugs will cost, but will only
last 2.5 times as long. I change my standard spark plugs every 8,000
miles (12800 km).

Consider the valve adjustment interval. Some Honda and Suzuki
motorcycles require the valves to be checked at 16,000 miles (25,600
km) and some Yamaha motorcycles recommend checking the valves at
26,000 miles (42,000 km).

So, if I need to remove the fairing, gas tank and airbox at regular
intervals to check the valves, why not install the cheaper standard
spark plugs while the valves are being checked?

http://www.babcox.com/editorial/cm/cm120032.htm

"The main reason for using platinum electrodes is to minimize
electrode wear. Every time a plug fires, a tiny amount of metal is
vaporized and lost from the surface of both electrodes. The center
electrode typically suffers the most wear because it runs hotter than
the side electrode."

"As the electrodes wear, the air gap across which the spark must jump
becomes wider and wider. The gap on a standard spark plug grows about
0.00063m. to 0.000126 in. for every 1,000 miles of normal driving. And
the wider the gap, the greater the voltage needed to jump the gap. On
standard plugs, the firing voltage requirements creep up about 500
volts for every 10,000 to 15,000 miles of driving. Eventually, the
plug may need more volts to fire than the coil can produce, causing
the plug to misfire."

"Using platinum almost eliminates electrode wear. Platinum is
expensive, but it can double or even triple a spark plug's normal
service life - from 30,000 to 45,000 miles for a standard plug up to
60,000 to 100,000 miles or more with platinum. Most aftermarket plug
suppliers do not make specific mileage claims for their platinum
plugs, but say to follow the OEM replacement intervals - which in most
cases is 100,000 miles for platinum plugs."

"Denso and NGK have both introduced new premium plugs with iridium
alloy electrodes. NGK says iridium is even better than platinum in
terms of corrosion, and resistance and ignition performance."

 

Are you sure it's not because of the polarity of the coil?

Single platinum tipped plugs aren't recommended for engines using double-ended coils.

Harley only offers double and triple tipped plugs to address this issue.

 

You may not have noticed that the statement was a quote from
http://www.babcox.com/editorial/cm/cm120032.htm

"But the Barrister, weary of proving in vain
That the Beaver's lace-making was wrong
Fell asleep, and in dreams saw the creature quite plain
That his fancy had dwelt on so long."
----Lewis Carroll http://rpo.library.utoronto.ca/poem/438.html

 

James Clark schreef:

I've been in the DC-welding area for some years and did lab work
on electrodes. Measuring temperatures like I did cannot be compared
to whatever happens inside a combustion chamber and how tip and
side electrode of a spark plug can get rid of the heat, but:

When you have two identical electrodes, the minus gets hotter than
the plus, and the plus wears faster.

Reason is that the negative electons are lighter than the
positive particles (atoms with a few missing electrons).

Wear is easy to understand. The positive electrode spits out
atoms+electrons. The negative spits out electrons only.
And the positive electrode thus wears faster.

Temperature difference comes because the negative
electrode is bombarded with (heavy) atoms, and
the positive electrode is bombarded with light electrons.
The kinetic impact energy of the atoms heats the
negative electrode more than the electron bombardment
does to the positive electrode.

Like I said, the difference in temperature cannot be
compared to what happens in the cilinder.
But the positive electrode will wear out faster anyway.

I don't know why Platinum lasts longer. It really does.
We used Wolfram (Tungsten) for electrodes. It may have to do with
the internal bonding force between atoms, but this is a guess.

And further:
Did I ever buy Platinum spark plugs?
No. Not worth the price.

Rob.

 

http://www.densoiridium.com/faq.php

"Q. What makes Iridium better?

A. Until recently, platinum was considered the best material to use on
the top of an electrode because of its durability. However, Iridium is
6 times harder, 8 times stronger, and has a melting point 1200 degrees
higher than platinum. Put that into a harsh environment such as an
engine piston chamber, and you have a spark plug that can resist wear
much better than platinum. Additionally, the DENSO Iridium Power alloy
is so durable; it allowed our engineers to produce the world's
smallest center electrode (.4mm) which reduces the voltage
requirements, concentrating its sparking power. Also, its smaller
size, combined with the tapered U-Groove ground electrode, allows more
room for the flame kernel to develop and produce a more efficient
combustion."

http://www.theodoregray.com/PeriodicTable/Elements/SparkPlugs/index.html
Elements in spark plugs

http://en.wikipedia.org/wiki/Spark_plug

"At one time it was common to remove the spark plugs, clean deposits
off the ends either manually or with specialized sandblasting
equipment and file the end of the electrode to restore the sharp
edges, but this practice has become less frequent as spark plugs are
now merely replaced, at much longer intervals. The development of
precious metal high temperature electrodes (using metals such as
yttrium, iridium, platinum, tungsten, or palladium, as well as the
relatively prosaic silver or gold) allows the use of a smaller center
wire, which has sharper edges but will not melt or corrode away. The
smaller electrode also absorbs less heat from the spark and initial
flame energy. At one point, Firestone marketed plugs with polonium in
the tip, under the questionable theory that the radioactivity would
ionize the air in the gap, easing spark formation. (See external link
below)"

http://www.theodoregray.com/PeriodicTable/Elements/SparkPlugs/index.html
Elements in spark plug

I tried about two sets of Champion Gold Palladium plugs in the
mid-1970's. Their claim to fame was that they ran too hot to foul with
the rather low voltage available from the coils. The part$ guy who
touted them to me said that I shouldn't worry about the fact that the
center
electrode would actually *melt* into a round blob...


"The Witnesses proved, without error or flaw,
"That the sty was deserted when found:
"And the Judge kept explaining the state of the law
"In a soft under-current of sound.

"The indictment had never been clearly expressed,
"And it seemed that the Snark had begun,
"And had spoken three hours, before any one guessed
"What the pig was supposed to have done."---Lewis Carroll, "The
Hunting of the Snark"

 

On a spark plug, we've got nothing like two identical electrodes.

The center electrode is fairly long and how well it's connected
to the heat sink (cylinder head) is one of the factors that determines
the plug heat number.
The side electrode is short, relatively thick and thus well connected
to the heat sink. OTOH it is very exposed.

AFAIK, transport of metal between the plug electrodes is the
last thing we want to see.

If I may make a guess, I would say that the heat of combustion
totally dominates over any electrically caused heating.

 

OH- schreef:

I said *When*, I talked about lab-conditions.
And yes. We could make a fortune if we invented one and marketed it
right: 'More power, longer lifetime. less fuel consumption, good for
the environment, girls love it'. I'd fall for the last reason.

It is inside insulator material, but I know what you mean. BTW, an
electrical
insulator usually also is a good thermal insulator.

Yes, there is no formula to calculate which one is the hottest.

Correct. But we see it. If it wasn't the case you'd never have to
install new plugs.

No guess needed. It does.

Let me retry to write what I wanted to say:

Heat is movement of atoms. The hotter, the faster they
move, or- in solid material anyway- vibrate.
Many atoms on the surface of hot material will jump off of the
surface, but most will be pulled back onto the surface
because of the force that holds atoms together.
But some will escape (if temp is high enough).
Water already does that at room temperature. We
call that evaporation. But note that evaporation does
not mean that the metal must be in a liquid phase.

If there is a negative electrode close by (an
electric field), then there will escape more
atoms from the positive electrode, because
the negative electrode pulls on them.

So *at equal temperature(!)* a positive electrode
will loose more atoms over time than a negative
electrode.

I don't know wether center or side is the hottest,
but the fact that usually the center is cladded with
expensive material makes me think that the center
is the hottest, or that the electric field helps the
center to loose atoms most, or maybe both things
together is the reason for center cladding.

Rob.