spark plug question for a six Options

[rfuerst911sc]

I just ordered some Clewett spark plug wires for the six and I'm going to change the plugs at the same time. Ignition rotor and cap are only 6 months old. Engine is a stock internal 3.0 with Weber carbs and Mallory multi spark ignition. All my records are still in moving boxes and I haven't pulled the old ones yet so what are the recommended plugs/heat ranges for street driving ? I generally like NGK standard copper plugs but have run copper Bosch in the past. Thanks and happy new year (IMG:style_emoticons/default/beerchug.gif) .

[Cap'n Krusty]

Well, I disagree with you, and I've been working on Porsches since 1963. Champion plugs had, at that time, and for a long time thereafter, cut threads, while Bosch, Lodge, NGK, Beru, and possibly others, had rolled threads. I don't know if that's still the case. Cut threads were hell on aluminum heads, and we saw thread damage on countless engines, both VW and Porsche, that were running, or had run, Champion plugs.

As for you "Not Made Here" theory, VW, BMW, and others come with NGK plugs as original equipment, and Porsche has used both Motorola (US) and Valeo (French) alternators and regulators for years.

The Cap'n

[ME733]

Well, I disagree with you, and I've been working on Porsches since 1963. Champion plugs had, at that time, and for a long time thereafter, cut threads, while Bosch, Lodge, NGK, Beru, and possibly others, had rolled threads. I don't know if that's still the case. Cut threads were hell on aluminum heads, and we saw thread damage on countless engines, both VW and Porsche, that were running, or had run, Champion plugs.

As for you "Not Made Here" theory, VW, BMW, and others come with NGK plugs as original equipment, and Porsche has used both Motorola (US) and Valeo (French) alternators and regulators for years.

The Cap'n

................Well capt. lets see, The carrera 4 cam engine you spoke of in an earlier post...One of the highest output per cubic displacement ,carburated naturally asperated, engines of all time...USED CHAMPION plugs.....the since 1963 porsche engines as you you state, ALL have helicoil inserts,(all 356 engines have heli-coil inserts)(factory installed) therefore the spark plug has NO direct contact with the aluminum cylinder head. The only way anyone can have a problem is IF you remove the spark plug in a red hot engine...which knowledgable engine guys would never do...Additionally knowledgable engine guys use a small dab of Anti-sieze on the plug threads, wether or not the spark plug threads are heil-coiled or not...The type four engine heads do not have heli-coil spark plug inserts. A dab of anti-sieze on the plug threads is essential to preserve head thread integrity.