Plugs last way longer than in days of old BUT if you have an alloy head, it is wise to unscrew and re -torque every year, otherwise they can become stuck in the head and could possibly lead to major surgery to remove.
If you do that, be sure to change the compression washers as they're a once fit item, if you just keep whipping your plugs in and out to inspect them and or to keep the threads chased but don't replace the compression washers, you will not get the correct seal and your torque reading will be wrong too.
You can buy compression washers from Tim Green at the Green Spark Plug Company, I would buy your plugs from him too as he offers excellent customer service, fast delivery and his prices are very competitive too.
https://www.gsparkplug.com/10x-budget-spark-plug-steel-crushable-washer-washers-14mm.htmlHi everyone. A simple question I hope ? I only ever use NGK plugs and have BPR6ES currently fitted in my highly modified Plus8 engine. Is it worth paying 4 times as much for the equivalent NGK BPR6EIX Iridium plug ? I know they last longer, but since it's only £24 for a set of the standard plugs, I'm happy to frequently change them.
Stay safe, John.
1999 Plus8
My Rover V8 spark plug experience includes 11 years of ownership and almost 100,000 miles driving my TVR Chimaera, this proved you won't really notice any difference between a nickel or iridium electrode, they're all copper core by the way. In my TVR's RV8 I experimented with NGKs expensive specialist platinum chip ground electrode iridium tipped LPG plugs, BPR6EIX Iridium, and good old BPR6ES.
I found I was much better off using BPR6ES and putting the money saved into replacing my HT leads every 2-3 years, I changed my BPR6ES every 7,000 miles which I also felt was way better than leaving a set of long life BPR6EIX sitting in my heads for 60,000 miles. Mr Retro Leads offers good quality sets for the RV8 or you can buy the leads and ends separately from him and make your own set up for a good saving which is what I did, however, to make a proper job of it you absolutely must use a pair of proper HT lead crimping pliers.
Actually, in the end I found the ultimate plug for my Rover V8 was the one hotter BPR5ES, all Rover V8s put a bit of oil into the combustion chamber so running a hotter No5 removed any ash deposits produced by combusting engine oil and the heavy ends present in LPG. I found HT lead failures were largely caused by plug fouling, when running cooler No6's deposits would built up on the centre electrode within just 4,000 miles and to the extent where the current would prefer to burst the HT lead and ground to the head, rather than through the plug's ground electrode as it should.
By switching to the one hotter BPR5ES all the fouling went away, the No5's self cleaned beautifully and lasted 10,000 miles, as the Rover V8 is a low compression engine there's also zero risk of detonation or pre-ignition, I must have done 50,000 miles on BPR5ES changing them every 7,000 miles with perfect results.
I would also advise against using CopperSlip or other anti-seize greases, what people seem to forget is all these greases are adding a layer of insulation which is the last thing you want on a spark plug as a good ground contact with the cylinder head is essential. This is why NGK developed their trivalent plating, this silver or chrome-colored finish on the threads is designed to provide corrosion resistance against moisture and chemicals. The coating also acts as a release agent during spark plug removal, all NGK spark plugs are installed at the factory dry, without lubrication or anti-seize, we should all do the same. Also if you're still worried about plugs seizing in the heads of your RV8 just take a moment to look down the plug holes and you'll soon see the threads always receive some oil creep, trust me that's more than enough lube to ensure your plugs wont pull the threads, just let the head cool right down before removing you plugs and you'll have no issues despite no anti-seize greases being used.
