I'm getting ready to change my spark plugs. I've been using AC or Bosch
standard configuration plugs. I keep seeing ads for the SplitFire plugs and
even some Bosch 2 or 4 conductor plugs. Rather than blow the cash and find
out for myself, does anyone have anything good to say about these style
plugs? I know how they're SUPPOSED to work, but do you actually notice a
power gain or any increased fuel efficiency?
Either way, does anyone have some advice on where to set the gap for a
typical 5.7 liter with 155k miles on it? I've just been using the gap that
Checker Auto Parts gives me with new plugs.
If your planning on trying out any modified electrode plugs go with the AC Delco
Rapidfire as Doc
pointed out. These plugs 'do' work as advertised plus there about $3 each, less
than splitfire and
other platinum plugs. But they will wear out, unlike platinum tip plugs.
Also these are AC branded products.
These plugs are 'pregapped' http://www.acdelco.com/html/faq_plugs.htm
BTW i've tried Bosh platinums, and the AC's resulted in a smoother idle.
Why .035 as opposed to the sticker in the engine bay that says .060? And on
another note, I've seen it recommended by the manufacturer of the plugs to
be at .045 for the same vehicle that says .060. I've never understood the
difference the gap makes. Can anyone clear it up?
A brief answer, and others can go into detail if they wish. The gap
controls how "hot" the spark is. Not sure on the recommendations by Doc,
but my guess is that the multiple electrodes (or electrode points on a
single electrode) cause a variance in the recommended gap. The actual
distance of the gap is NOT the real issue, but the intensity of the spark
is. The distance for the gap is just the way to control that. Perhaps a
bit over simplified, but should get you a better understanding 'till someone
with a deeper knowledge wants to expound further.
It actually has to do with voltage, electrode area, and the internal compression
If you running an MSD or other ignition system that has voltages higher than
stock then you could go
But most ignition systems like to see 0.035 at the normal compresion pressures.
However, Rapidfire plugs are gapped from the factory (at at\round 0.040) for
application because of their electrode area.
Derek Schwartz wrote in
The plugs I took out were Autolite's and the electrodes were melted at
Why am I not surprised. Autolites are the worst junk out there, yet a lot of
people swear by them. Anytime I've used them in the past (parent's car).
They have melted or in two seperate instances...exploded.
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