Cascade Crew

nonsensekid20 · Posted: Thu Mar 15, 2012 7:19 pm Post subject: Time to change spark plugs

Alright, so looking on summit, my head is spinning with all the different types of spark plugs. Is there really a benefit to the different types? (silver core vs copper core, or copper tip vs silver tip)

aaron_sK · Posted: Thu Mar 15, 2012 7:47 pm Post subject:

Autolite 24

nonsensekid20 · Posted: Thu Mar 15, 2012 8:14 pm Post subject:

I have Autolite 26's. Why would I go to a colder plug? Or why would I go to that cold of a plug to begin with?

fiveoformula · Posted: Fri Mar 16, 2012 10:34 am Post subject:

You can get better performance from a cooler burning plug because its less heat which means you could advance the timing more before it pings in theory. Hotter plugs are better an older worn engine because they put up with oil burning or carbon or what ever else is in the combustion chamber. Atleast this is how I understand plug heat ranges. I also prefer the step colder NGK UR5 because there shorter than autolites. Makes them easier with headers.

aaron_sK · Posted: Fri Mar 16, 2012 4:12 pm Post subject:

Derek nailed it. But play with it a bit. Plugs are cheap, buy a few and see what your motor likes, what it fouls and what it cooks.

BTW, all the jazz about the NGK's being shorter, that's true on the SBC, but for those of us with a crazy 3800 build the NGK's are actually longer

nonsensekid20 · Posted: Fri Mar 16, 2012 8:04 pm Post subject:

Alright, well I have the 26's in there now, so I'll try out the 24's and see how it does. Thanks guys

fiveoformula · Posted: Mon Mar 19, 2012 11:09 am Post subject:

There ya go. And maybe an autolite 25 is a happy medium if the 24s don't last long enough for you.

Twilightoptics · Posted: Mon Mar 19, 2012 1:12 pm Post subject:

I ran 25's for years in my 330RWHP 350. They were great.

I perfer NGK however, but they wouldn't fit my aftermarket head.

If your motor is mostly stock, just get the OEM replacement and be done with it. If you burn oil and run rich, get the next heat range hotter.

NGK heat range numbers get hotter as the number drops. Autolites get hotter as the number increases.

91RSVert · Posted: Mon Mar 19, 2012 5:47 pm Post subject:

Off the wall question since were on plugs.

Lets say your getting smogged check and your motor is right on the edge or passing. Can you go one hotter/colder and make it work? If so, what way?

I know on boosted engines, the higher the boost, the colder you want to go. I had run 2 colder on my L67 with 10lbs of boost.