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Re: Spark Plugs

There is an old dragsters trick to get all the performance out of your 
plugs. If you install the spark plugs so that the open side of the 
electrode is facing the intake valve, it is said to improve the 'burn' 
as opposed to being 180 degs. away, with the 'post' of the electrode 
facing the in coming fuel. The way they accomplished this was:
1st. Put a mark (magic marker)on the plug insulator indicating the      
open side.
2nd. Install the plug and note where the mark is facing. If by      
chance it's facing the intake valve, no adjustment is needed.
     If it isn't, add a "shim spacer", (purchased from your local
     performance shop), as required to position the plug. These spacers 
come in several different thickness in order to get the right position. 
Keep changing the shim ring thickness until the plug has been position 
as above.

I personally have never gone to this much trouble, but have heard that 
it does improve performance, how much I don't know. But it does make 
since. Even in the sales literature of my car, they show a cut-away view 
of the combustion cylinder, with the 'duel tips' open to the intake 
valve. Maybe they just showed it that way to make it look pretty.
In your case, I believe your plugs have duel electrodes as well, so 
position them so that the open side faces the intake valve(s). If anyone 
goes to this trouble, let me know how it works out.

Richard Vaughn
BMW CCA #132931 Tarheel Chapter
'95 740i

Date: Tue, 24 Nov 1998 11:08:40 EST
>From: [email protected]
>Subject: Re: Spark Plugs
>
>In a message dated 11/24/98 7:58:02 AM Pacific Standard Time, 
owner-bmw-
>[email protected] writes:
>
><< Platinum's are supposed to burn hotter/cleaner, and last
> longer.  They were also cheap in price.  >>
>
>I agree with you on the cleaner burning, but copper is a far better 
conductor
>than platinum.  The main reason platinums are used is that it lengthens 
the
>service interval.  Also, dont expect an increase in performance by 
switching
>to a different plug.  It just does not happen.  Also, dont 
expect/believe all
>the hype about Jacobs ignitions improving performance, either.  Just 
more
>snake oil in a different bottle.
>Dave
>98 M3/4




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