Spark Plug Analysis

AG98RT10

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Changed plugs/wires today and did a quick search on google to see what "normal" plugs should look like; mine pass. Wondering if anyone here has more detailed analytical input like the for-pay sites that will sell you detailed info on how to read your plugs to tell more about your mix, timing, etc.
Mine look rather good, at least in comparison to the pictures on the NGK site, but don't know how long they were in there, since I got the car in Feb.
Seems to run a little faster and smoother now too! :2tu:
 

Chuck 98 RT/10

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I change my plugs and wires every 20K. Cost is under $80 and if you wait much longer you wont notice the gradual loss of power until some Corvette beats you.
 
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AG98RT10

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Thanks, Chuck, for reply. I'm thinking I'll change plugs every 10K (only 11 bucks!) and wires every 20K. I did notice all my gaps were up to 45 thousandths, due primarily to erosion of the electrode. Seems logical to em to keep fairly new plugs in to keep the gap close to the factory 35.
Believe my plugs may have been there since birth, since I bought the car at 16K and they were stock Champions (which I replaced them with). Wires were dated '98 too. But glad they all looked good anyway.
Maybe I'll pull one in 10K and give it a good look-see, then change all ten is it seems to be worn much.
 

Chuck 98 RT/10

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When I first got my Viper I wanted to see for myself how long plugs/wires lasted so I waited until I noticed poor performance before changing them. At 30K fresh plugs very noticeably restored performance, the same thing with the wires at 40K. So I determined change them both at 20K and be done with it for a year or two.
 

Makara

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I tried Bosche platnuims in my RT. I hated them. The car ran like crap. I changed them out for the Champions and the car ran fine again.
 

ViperJoe

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Champion “Regular Class” - Traditional #RC12LYC (what’s in there from Mopar)

Champion “Super Class” - Single Platinum #3034
Platinum center electrode, resistor plug, 14mm, 3/4" reach, 5/8" hex head, .290 core nose projection, copper core. **

Champion “Premium Class” - Premium Gold #2412
Gold Paladium performance plug, resistor plug, 18mm, .460" reach, taper seat, 13/16" hex head, extended electrode gap & core nose projection. **
Gold palladium - Gold is an excellent conductor of electricity, which makes it well suited for a performance plug. However gold is also a very soft metal, therefore the gold alloy is mixed with palladium, (a much harder metal), to form a premium fine wire performance plug with increased ignitability and durability.


Autolite Single Platinum #AP985 **

Autolite Double Platinum #APP985 **


Bosch PLATINUM #4203 **

Bosch PLATINUM+2 #4308 **

Bosch PLATINUM+4 #4428 **

Bosch SUPER PLUG #FR9HC **


Denso 5018 QJ16HR-U

GAP .035

** It is still not suggested that platinum plugs be used on vehicles with nitrous injection (from Champions website)
There have been instances where the platinum tip has lost its bond to either the center or ground electrode when they were used in a motor with nitrous.

The spark plug can help maintain the optimum combustion chamber temperature. The primary method used to do this is by altering the internal length of the core nose, in addition, the alloy compositions in the electrodes can be changed. This means you may not be able to visually tell a difference between heat ranges. When a spark plug is referred to as a “cold plug”, it is one that transfers heat rapidly from the firing tip into the engine head, which keeps the firing tip cooler. A “hot plug” has a much slower rate of heat transfer, which keeps the firing tip hotter.

An unaltered engine will run within the optimum operating range straight from the manufacturer, but if you make modifications such as a turbo, supercharger, increase compression, timing changes, use of alternate racing fuels, or sustained use of nitrous oxide, these can alter the plug tip temperature and may necessitate a colder plug. A rule of thumb is, one heat range colder per modification or one heat range colder for every 75–100hp you increase. In identical spark plug types, the difference from one full heat range to the next is the ability to remove 70°C to 100°C from the combustion chamber.

The heat range numbers used by spark plug manufacturers are not universal, by that we mean, a 10 heat range in Champion is not the same as a 10 heat range in NGK nor the same in Autolite. Some manufacturers numbering systems are opposite the other, for domestic manufacturers (Champion, Autolite, Splitfire), the higher the number, the hotter the plug.
For Japanese manufacturers (NGK, Denso), the higher the number, the colder the plug.


Remember, CHAMPION PLUGS GET HOTTER THE HIGHER THE NUMBER, COLDER THE LOWER THE NUMBER.

Say you are starting with a RCJ7Y
if you want a COLDER plug, you would use RCJ6Y
if you want a HOTTER plug, you would use RCJ8Y


http://www.championsparkplugs.com/sparkplug411_champion.asp
 
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