Spark Plugs, hotter or colder???

[Macs Stang]

Ok, i am running some oem autolites right now, and I was just wondering what a hotter or colder plug would do for my car. I have heard that a hotter plug would cause the engine to run hotter, yet burn the gas more efficiently hence giving the car more power.

I know colder plugs are usually for blower/nitrous cars so I don't think it would do anything for my car.

Also, I am looking to replace my plugs soon anyways so I thought I would through this question out for other people that would be interested as well.

-Tim

[niterydr]

colder plugs: They are designed to last longer than oem applications under longer durations of load (like you said, nitrous or boosted applications). This is done via better control of heat which in turn leads to less gap erosion which leads to longer life, which is always good.

hotter plugs: These are designed for motors that do alot of idling, and operate at extended periods of time under low load, low speed applications. Running 'hotter plugs' in a 'race engine' can cause pre-ignition if the plug begins to glow due to the fact of inability to dispurse heat properly.

The best bet if you are unsure is to run a stock range plug. Index them properly, make sure the edges are sharp, and run as wide of a gap as possible. This will get you 'max power' out of the plug.
See us import guys aren't all that worthless , goodluck.

[Shadowgray03]

A good rule of thumb is going one step colder for every 75-100 hp over stock you go. Plugs play an important roll in cooling, they act as a conduit for channeling heat from combustion shamber into the coolant flowing through the head. If you go with plugs that are too cold the wont clean themselves at low RPM driving and will foul, if you go to hot, you risk detonation etc.

[Macs Stang]

ok with that said, then do you think i should just go with some oem plugs and then gap them a few tenth's more then factory recommended?

[TRDon]

ok with that said, then do you think i should just go with some oem plugs and then gap them a few tenth's more then factory recommended?

I second this question, I have wondered this for a while. I think a few tenths is pushing it but how about .10-.15? A stock ignition can suppotr that right?

[lilstang5O]

i got colder Autolights on mine, runs great!

[-D]

I went colder NGK's but I intend to run nitrous soon

[TitaniumGT]

I've heard the Autolite 103's work good on stock headed applications, I was gonna try it last year, but I ended up with aluminum heads sooner than expected.
There worth a shot I guess.

Nick

[Joe Goebbel]

Hey Tim, if you have time to read. Check this out. Say's pretty much what everyone else say's but a little more in detail.

http://www.ngksparkplugs.com/techinfo/spark_plugs/techtips.asp

[Sleeper]

A Lesson In Terminology: Plug Gaps


Lets say the recommended gap is .055". This is read as "fifty-five thousandths" of an inch. Adding 'a few tenths' would bring this number to .255"...two hunderd and fifty-five thousandths...or just over a quarter of an inch. Not good.

...a few tenths is pushing it but how about .10-.15? A stock ignition can suppotr that right?

Using what we have learned in the lesson above, I am sure you meant .010"-.015"....ten to fifteen thousandths of an inch...or about the thickness of 5 sheets of that printer paper next to your computer. And yes, a stock ignition should support that. My stock plugs were gapped anywhere from .060"-.073" when I checked them before I put the new ones in. My new ones are gapped at .055".

[TRDon]

A Lesson In Terminology: Plug Gaps


Lets say the recommended gap is .055". This is read as "fifty-five thousandths" of an inch. Adding 'a few tenths' would bring this number to .255"...two hunderd and fifty-five thousandths...or just over a quarter of an inch. Not good.





Using what we have learned in the lesson above, I am sure you meant .010"-.015"....ten to fifteen thousandths of an inch...or about the thickness of 5 sheets of that printer paper next to your computer. And yes, a stock ignition should support that. My stock plugs were gapped anywhere from .060"-.073" when I checked them before I put the new ones in. My new ones are gapped at .055".

Totally right on this. Thousanths is definately what I meant. I kinda laugh now thinking of gaping 1/4 inch in a plug! I feel stupid Thanks for clearing this all up though, I hope no one got the wrong idea or mesleading information.

[PHRANQUY]

i agree with the Autolite 103's. I have been told on the 2v motors though that you need to go with a colder thermostat and sometimes a tune as well though.

[Macs Stang]

so if i went with the autolite 103's would that have any effect on my tune that i just recived this weekend? hence anything to do with spark?

if they say to gap at .05 and i want a little better spark what should i gap the plugs to. i am kinda retarded when it comes to spark plugs.

[mnstang]

if you'd want a stronger spark, you would reduce the plug gap. i think spec is about .055-.060", either way it says on that little plastic coil cover thing, if you still have that
i wouldn't go that large though.

[Macs Stang]

greg, so what do you think i should do? get a set of autolite 103's and gap them less then .055?

what would a colder plug do for my engine? increase/decrease temperatures, performance, driveability?