[Fot] Subject: Indexing plugs

[BillDentin at aol.com]

In a message dated 05/05/2012 6:17:11 PM Central Daylight Time, 
Catpusher at aol.com writes:


> We could not measure any change, and we run popups and a high CR; we went 
>  
> to MSD and then Electromotive and ran to 7200RPM with our TR3.
> 

Hi Hardy...

7200!  WOW!

Our mechanic, Kevin Potter, said that he used to index the plugs on our 
engines, but did not see any gains worth the effort.   Kevin was big in Karting 
for a while, with his two daughters as drivers.  He said that on the Briggs 
and Stratton Kart engines, there were significant gains to be made. Those 
engines were of a flathead design. It seemed the shrouding of the electrode 
was more important on that type of engine. He thinks, usually the main reason 
for indexing is with a domed, or popup piston, if they are not indexed 
properly, when the piston is at TDC, it will smash the plug because of 
clearance.

Bill Dentinger