6 replies to this topic

[wakkoboi]

1985 998, standard, with a 74 degree thermostat

what sort of spark plugs do i need? there are too many to choose from and far too confusing to a muppet

[Ethel]

BP6ES,GSP163,N9Y or equivalent

[wakkoboi]

whats the difference? just out of curiosity?what makes a good spark plug good etc?

[wakkoboi]

and thanks for your reply

[Retro_10s]

You will seldom find a 'bad' spark plug,.. but it is easy to find a plug that is 'bad' for your set-up. Champion and NGK are probably the most popular makes.

what makes a good spark plug good etc?

Same as any other product, the quality control of production, the materials used to build it and the price!!!

Very basically you want a Copper Core on a Spark plug rather than a steel one as it will draw the heat away from the tip faster...

Or to cut a long story short. Buy NGK or use the search function, plenty of spark plug topics...

[Ethel]

The 3 I listed are just different manufacturers part numbers. Most of the manufacturers will have techie info explaining their own numbering system on their site. Apart from plugs that have built in resistors (useful for suppressing interference with radios and electronic engine management) the major difference is a plug's operating temperature. A performance engine will like a plug that dissipates heat well to avoid detonation but if a plug is too good at dumping heat it will get sooted up during warm up and may never get up to temperature if the engine is just bimbling about on part throttle for a few miles. If the soot isn't burned off the plug will eventually foul 'n stop firing.

[wakkoboi]

ok thanks again