>Here I go again, ranting... I work on cars and
>light trucks for a living. I realized yesterday as
>I was removing yet ANOTHER set of Bosch Platinum sparkplugs from a
>customer's car that
>good people on this list mght have fallen into this trap.
> In my part of the world the DIY auto parts
>stores push these pieces of junk. They are completely unacceptable for
>most U.S. cars
>and just about ANY older vehicle I can think of.
> If you have a BMW, Volvo, Mercedes-Benz, maybe...
>Here's what's wrong. I call it "running out of
>spark". On the 'scope, a good sparkplug requires 7 to 13kV to fire.
>Most systems will
>max out (12v electronic ignition) at around 30 to
>35 kV. Older 6v systems will be less, 20kV?
> The difference between firing voltage and maximum output is like a
>reserve. As soon as you put the pedal to the metal that reserve begins
>to narrow. Add a heavy GVW, lean mixture, too wide of plug gap, etc, and
>the reserve is JUST enough to prevent misfire.
> Let's add Bosch Platinum plugs to the mix!
>They require somewhere around 80% of max output AT IDLE! You can see
>that your ignition
>system will "run out of spark" very quickly.
>God forbid you forgot to take the choke off or
>you happen to be running old gasoline! The
>spark will completely bypass this "huge resistor"
>of platinum electrodes and just run down the coated insulator.
> There MUST be someone on this list who has
>had problems with "high performance-long life"
>platinum plugs.
> I'm not just picking on Bosch, "Split fires", and
>other platinum plugs are just as bad.
> I know that certain vehicles REQUIRE platinum plugs. Use what came in
>them originally.
> If I hurt someone's feeling with this, too bad!
>It's the truth!
>Don Kenyon ASE Certified Master Automotive Technician, L-1, CA Enhanced
>Smog License
>
>
I find your comments interesting on the platinums.I remember when they were
being first introduced it was important not to gap them with steel feeler
gauges but instead teflon or plastic guages had to be used.the steel
scratches the platinum or paladium coating and causes havoc with the spark.
The split fire plugs are being or allready have been taken to court by the
FTC.There is a website on it and basically they are fraud.Don't do what they
claim.So is Slick 50.
I have a 72 Land Rover 88 California special.When I got it I changed the
plugs and put the newer Bosch(not platinum) plugs in.they lasted about a
year.I was a little pissed because the original Bosch ones in it were there
for 5 years.I recleaned the originals and got another 5 years out of them.
I have used Champions but don't like them because they have an unusually
high dud rate.AC's not much better,basically same company.NGK's by far the
best from what I have used.
Another good chuckle-a friend of mine(real cheap)owns a New
Yorker/318-decides to get 4 plugs and change one side-Canadian tire
crap.About 6 months later gets 4 Autolites.A year later checks his plugs and
find the Canadian tire ones are shot and the Auto lites still looked really
good.He's Scottish,what can I say.
Andre
This archive was generated by hypermail 2b29 : Tue May 01 2001 - 07:42:42 PDT