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#11
 
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Re: Platinum spark plugs? -
10-12-2009
, 04:41 PM
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On Oct 10, 12:17*am, sub... (AT) toddh (DOT) net (Todd H.) wrote: Yousuf Khan <bbb... (AT) spammenot (DOT) yahoo.com> writes: Can anyone tell me the pros & cons of going with a platinum spark plug over a regular copper one? Same question for the super-high-end iridium plugs. I've been told they're bad news in these engines and to stick with a regular NGK. -- Todd H. 2001 Legacy Outback Wagon, 2.5L H-4 Chicago, Illinois USA my wife's Outback (H6) has them from the factory. ??? |
more than every 60K.
Dave
#12
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Really, platinum is good for about 75-100,000 miles, and back in the day Toyota specified them for their EFI engines. I'd stay with what's proven. |
My dealer did finally replace the spark plugs, they were platinums. He
said that that's what's recommended for Subies.
Yousuf Khan
#13
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clare (AT) snyder (DOT) on.ca wrote: As far as Plats are concerned, if the engine is waste-fire (double ended coil) using single platinums is a waste of money - dual platinums are required to do the job properly. The single platinums were only $1.50 more than the non-platinums, so the cost is no big deal. Why are dual platinums required? What's the difference? My beaf with the long life plugs is unless you pull them to check them at about half life, there is a good chance they won't come out, at least in one piece, when required. Doesn't anti-seize lubricant prevent them from having trouble coming out? Yousuf Khan |
Yup...
#14
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Hachiroku ハチ*ク wrote: Really, platinum is good for about 75-100,000 miles, and back in the day Toyota specified them for their EFI engines. I'd stay with what's proven. My dealer did finally replace the spark plugs, they were platinums. He said that that's what's recommended for Subies. Yousuf Khan |
You can "upgrade" to iridium, but since you're replacing them you
probably have ~100,000 on the car. Sit back and relax for the next
100,000...
#15
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On Oct 10, 1:17*am, sub... (AT) toddh (DOT) net (Todd H.) wrote: Todd H. 2001 Legacy Outback Wagon, 2.5L H-4 Chicago, Illinois USA Second question, is it worth my time to try to change my own spark plugs? Today I tried doing it, and found everything was too cramped. Is this something that's easier done from underneath? A few of the wires were easily accessible, mostly the front cylinders, but the rear cylinders seem to be highly congested. I left them alone for now, awaiting opinions. Mine's an 2.5L H4 too. * Yousuf Khan |
#16
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Yeah, because they're so hard to get to- no one wants to change 'em more than every 60K. Dave- Hide quoted text - - Show quoted text - |
#17
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On Fri, 09 Oct 2009 19:11:41 -0400, Yousuf Khan <bbb... (AT) yahoo (DOT) com wrote: cl... (AT) snyder (DOT) on.ca wrote: As far as Plats are concerned, if the engine is waste-fire (double ended coil) using single platinums is a waste of money - dual platinums are required to do the job properly. The single platinums were only $1.50 more than the non-platinums, so the cost is no big deal. Why are dual platinums required? What's the difference? The platinum tip is designed to keep the electrode from "eroding" due to electron transfer (I think that's what it is called) - with waste spark half the plugs fire backwards - so it is the gtound electrode that "erodes" - dual plats have platinum wafer on both electrodes. |
http://en.wikipedia.org/wiki/Electromigration
That's a key concern in metal layers forming interconnect (wires) in
integrated circuits. The problem happens more often when the current
is relatively high and the width of the interconnect is minimum width
- especially when aluminum is used. Often design rules state that
there should be a minimum width to interconnects for certain
applications, and sometimes copper is added to aluminum to reduce the
effect. Now they use copper interconnects which aren't as
susceptible.
Platinum can certainly erode due to heat. I remember the Japanese car
specialist I take my cars to used to use Bosch single platinums. They
noted that quite a few came back with the center electrode pretty much
completely eroded. Those use a thin platinum wire buried flush in the
insulator. Since then they primarily go with Denso.
My understanding about spark plug effectiveness is that with
conventional plugs (that develop a corroded finish) a newer plug with
"sharp edges is easier to fire. Eventually the material wears away
and the edges blunt. If you've seen the NGK V-Power and Denso U-
groove, they're trying to add extra edges to the center or ground
electrode. Good double platinums don't seem to need the sharp edges
to fire properly if the platinum areas are properly sized to both keep
clean and prevent erosion.
#18
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On Oct 9, 4:21*pm, cl... (AT) snyder (DOT) on.ca wrote: On Fri, 09 Oct 2009 19:11:41 -0400, Yousuf Khan <bbb... (AT) yahoo (DOT) com wrote: cl... (AT) snyder (DOT) on.ca wrote: As far as Plats are concerned, if the engine is waste-fire (double ended coil) using single platinums is a waste of money - dual platinums are required to do the job properly. The single platinums were only $1.50 more than the non-platinums, so the cost is no big deal. Why are dual platinums required? What's the difference? The platinum tip is designed to keep the electrode from "eroding" due to electron transfer (I think that's what it is called) - with waste spark half the plugs fire backwards - so it is the gtound electrode that "erodes" - dual plats have platinum wafer on both electrodes. Not sure, but are you thinking of "electromigration"? http://en.wikipedia.org/wiki/Electromigration That's a key concern in metal layers forming interconnect (wires) in integrated circuits. The problem happens more often when the current is relatively high and the width of the interconnect is minimum width - especially when aluminum is used. Often design rules state that there should be a minimum width to interconnects for certain applications, and sometimes copper is added to aluminum to reduce the effect. Now they use copper interconnects which aren't as susceptible. |
Quote:
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Platinum can certainly erode due to heat. I remember the Japanese car specialist I take my cars to used to use Bosch single platinums. They noted that quite a few came back with the center electrode pretty much completely eroded. Those use a thin platinum wire buried flush in the insulator. Since then they primarily go with Denso. My understanding about spark plug effectiveness is that with conventional plugs (that develop a corroded finish) a newer plug with "sharp edges is easier to fire. Eventually the material wears away and the edges blunt. If you've seen the NGK V-Power and Denso U- groove, they're trying to add extra edges to the center or ground electrode. Good double platinums don't seem to need the sharp edges to fire properly if the platinum areas are properly sized to both keep clean and prevent erosion. |
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