Another spark plug lead question Gound cable?
 

I have my first 911 engine and found it curious that it has ground straps on the spark plug leads. The engine is a 1976 2.7S with CIS. I thought about replacing the leads as part of the install into my 914-6.

Do I need the grounded type?

What is the ground function?

Radio interference?

Are they the best?

Is the answer in Wayne's Engine Rebuild book? I haven't read it all yet.

Never seen a ground strap on a lead before.

TIA,

Rick Ollah

There are mixed opinions on the value of the shielding. It is generaly believed that it was used to prevent cis air box backfires. I like the look and keep them on my 1973.5 cis.
http://forums.pelicanparts.com/porsche-911-technical-forum/267917-ignition-wires-braided-not-braided.html
http://forums.pelicanparts.com/porsche-911-technical-forum/7497-ignition-wires-3.html
http://forums.pelicanparts.com/porsche-911-technical-forum/635312-what-purpose-grounded-plug-wires-2.html

Thanks for the reply and link Ed. I'm new to the 6 engine and appreciate the info.