[Diy_efi] OT - platinum plugs burning up wires

[Rick McLeod]

I have to agree on the turbo w/ plat's, I have 4
gas/turbo cars, and ALL of them (3 Volvos and a GM)
HATE plat's, stock OEM plugs w/ large electrodes seem
to create the best light-off of the mix under higher
boosts, which relates to higher compression. I don't
have a 'hi-comp' engine to relate to (my GM v8's are <
9:1) and plat's weren't around when I built my 10.5:1
GM BB nearly 30 years ago, so no experience there, but
would be interested to hear what folks running hi-comp
have learned.

Thanks, everyone, for the great disscussions so far.
And, what's even better, no flames! Thanks

--- David Allen <davida1 at hiwaay.net> wrote:

>   Didn't hurt my 1991 TBI 305 with stock ign.
> components.  Hasn't hurt my
> mother's 1989 LeSabre with Series I 3800 and DIS
> ignition. On all these cars
> the ignition leads last fine.  Had one coil failure
> that I couldn't explain
> on the 305 but I was using a coil of unknown origin.
>   Modern graphite core wires can be fickle.  The
> core may be brittle; or the
> wires may be stressed or pulled during the service. 
> A crack opens in the
> core and as the ignition fires across this crack it
> burns away more and more
> of the core. Finally the wire is open-circuit.
>   However my turbo engine does not run as well with
> Bosch Platinums as it
> does with standard plugs.
>   Maybe I am just lucky with not ruining ignition
> leads?
> David
> 
> 
> ----- Original Message ----- 
> From: Bret Levandowski
> To: diy_efi at diy-efi.org
> Sent: Saturday, September 10, 2005 5:26 PM
> Subject: Re: [Diy_efi] OT - platinum plugs burning
> up wires
> 
> 
> Platinum plugs have a higher core resistance and
> require more current and
> more precise control to fire. This is not true of
> all platinum plugs but
> most. If the resistance in the plug or across the
> gap is too much, the
> current can't 'escape' through it's normal path and
> it has to go somewhere.
> Always the point of least resistance, whether it is
> the cap/rotor or plug
> wires it is going to flow somewhere. Either way, it
> is going to burn
> something up; possibly even your coil.
> I have experimented with different plugs and
> different systems and have seen
> all types of failures. From what we saw, AC Delco
> platinum plugs will burn
> up coils and wires quite nicely on older motors.
> SureFire triple platinums
> work well in just about any type of performance
> motor (high comp/high energy
> ignition), but not so well in older or lower
> compression motors. It wasn't a
> 'scientific experiment', just what we saw happen by
> changing plugs. So after
> much rambling..... Yes, what the tech said is true.
> You can burn up ignition
> components using platinum plugs in non-platinum
> applications. I have done it
> myself and had to have someone else tell me why.
> Unfortunately, you don't
> know 'til you try.
> 
> Rick McLeod <dunvegan at sbcglobal.net> wrote:
> Sorry for being off topic, but I know there is a lot
> of knowledge in this area on this list, and this
> might
> be of interest to discuss (remember the recent plug
> discussion?)
> 
> Recently I had an issue w/ a Hyundai where the plugs
> were replaced w/ platinum at a tune up. A few
> k-miles
> down the road, the car began running poorly, and was
> taken to the dealer where it was diagnosed as having
> 'burned up ignition wires'. The service advisor
> stated
> that you MUST NOT use platinum plugs in these cars
> since it will cause this to happen.
> 
> My question is: What is different about them that
> would cause this, it sounds like 'bunk' to me, but
> am
> looking to the vast world of knowledge on this list
> to
> get some insight.
> 
> Thanks
> 
> _______________________________________________
> Diy_efi mailing list
> Diy_efi at diy-efi.org
> http://lists.diy-efi.org/mailman/listinfo/diy_efi
> 
> 
> 
> Click here to donate to the Hurricane Katrina relief
> effort.
> 
> 
> 
> _______________________________________________
> Diy_efi mailing list
> Diy_efi at diy-efi.org
> http://lists.diy-efi.org/mailman/listinfo/diy_efi
> 
> _______________________________________________
> Diy_efi mailing list
> Diy_efi at diy-efi.org
> http://lists.diy-efi.org/mailman/listinfo/diy_efi
>