Date:         Wed, 3 Apr 1996 21:02:37 +0000
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         sw@smus.bc.ca
Subject:      Re: spark plug orientation affects performance?

Sami Dakhlia writes:
> 
> I read somewhere that it may be advantageous to install spark plugs
> so that their open end faces the intake valve.  This can be achieved
> with the help of washers. This is to prevent the spark from occuring
> in the shadow created by the electrode. Comments?

    Isn't that referred as "degreeing the spark plug"?  I have heard
    of this being done in racing engines.

-David

Some marine engines use a plug with no electrode 'arm' - simply a 
centre anode (or is it electrode?) surrounded by a gap, then a 
circular electrode. Like shaving the arm off a regular plug, then 
grinding the centre post flush. I imagine the combustion chamber has 
to be designed for this, though. I'm not sure of the main reason for 
this, altough I expect longevity is one of them.

==============================
Shawn Wright, sw@smus.bc.ca
'85 Jetta TD, 345k (Jenni)
'88 Westy, 324k (Kyra)
==============================