Re: Re: Ping Report - Updated

From: Mike Schwall (mschwall@flash.net)
Date: Mon Jan 24 2000 - 22:09:51 EST


>I wonder what year they started using the metal spark plug
>shields? Are these on the 96 5.2's ??? I know Bernd said he
>spotted traces of arcing? Could they be part of the problem?
>Maybe we should compile a list of manufactured differences
>between the 96 & 97 Magnum engines and try to eliminate them
>one by one. Logical? Just a thought.
>
>GS -

Nah, the pinging is caused by either a casting problem with the heads,
combustion chamber shape, spark plug position, or a computer problem
(ignition timing). I can't see how external arching will cause preignition
(ping). All that arching will do is reduce the voltage going to the plug
where it counts. Electricity will go were there is a least amount of
resistance to ground. All resistor spark plugs have a 5K Ohm resistor in
them to reduce electromagnetic interference (EMI). It takes 1 million
volts to arch across 1 meter of air. Do the math and figure out how much
voltage it takes to jump from the plug hex nut to the heat shield. It
takes 1KV to push through the resistor in the spark plug with a stock plug gap.

As I mentioned before, try spark plugs two (2) or even three heat ranges
COLDER than stock to check and see if it's the plugs causing the
preignition (plug being too hot). If you go two or three heat ranges
colder and it still pings, your problem is elsewhere, either with a casting
flaw or design problem causing a hot spot or multiple hot spots or it's a
computer problem (ignition timing curve, air fuel mixture curve or spark
advance delay problem - not keeping up with engine RPM and load). More
research is needed, on our part. Chrysler probably has the solution to the
problem, but it probably costs too much to fix the situation on all the
vehicles.

Mike

__________________________
mschwall@flash.net



This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 11:47:02 EDT