spark plug gap and heat range
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spark plug gap and heat range
i was wondering if there was a modified spark plug gap or heat range i should consider when purchasing plugs. i now run ac delco platinum plugs with .050 gap per factory spec. car runs fine just alittle rich smelling at idle.i was thinking that maybe a bigger gap would help burn the charge better and was also kind of looking for more info on heat range of plugs is this gap size or something else all together. all metering on car works fine no codes and like i said car runs very well.i get about 16 mpg on average. it may be the tune im smelling, just wondering
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Re: spark plug gap and heat range
okay some research yielded info on heat range of a plug, and it has nothing to do with gap, it more or less has to do with the insulator inside the plug how long or short it is represents how cold or hot it will be. low speed short trip driving=needs hotter plug, high speed long term driving =needs colder plug. still wondering about the gap though
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Re: spark plug gap and heat range
Do you not have cats? That is probably why your exhaust stinks.
How big of a gap you can run is somewhat dependent on how stout your ignition is, how much compression you have, and how lean you're mixture is, etc. A larger gap makes the ignition work harder at making the spark jump so you can try running a larger gap unless the spark blows out at peak torque, then you would have to close it back down. You shouldn't mess around with the gap on a platinum plug and they are more of a mileage plug anyhow. .050" is a big gap anyway - I don't see any benefit in trying to go larger than that. One thing you could do is put a scanner on you car and see what the O2 sensors are doing and what your fuel trims are at, since if you do have some minor problems, they could cause your engine to run a litle rich.
How big of a gap you can run is somewhat dependent on how stout your ignition is, how much compression you have, and how lean you're mixture is, etc. A larger gap makes the ignition work harder at making the spark jump so you can try running a larger gap unless the spark blows out at peak torque, then you would have to close it back down. You shouldn't mess around with the gap on a platinum plug and they are more of a mileage plug anyhow. .050" is a big gap anyway - I don't see any benefit in trying to go larger than that. One thing you could do is put a scanner on you car and see what the O2 sensors are doing and what your fuel trims are at, since if you do have some minor problems, they could cause your engine to run a litle rich.
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Re: spark plug gap and heat range
I have no cats. I do have an air fuel gauge hooked in line with the o2 sensors and it maintains a stoich reading getting richer under wot then returning to stoich again no codes for heater circuits on o2 or anything may just be the tune I've had this car for two years it's always seemed alittle rich but I was just wondering
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Darth_tsunami
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Sep 18, 2015 01:57 AM