Use to run NGK's in my street and race car stuff years ago but went to Champion with my new stuff because that's what Edelbrock and 440 Source recommended for their heads but they just seem to foul way too easy!!
Both my combos run on pump gas and both around 11.0 comp. race motor is a 500 ci with CNC'd Eddy heads, roller cam and tunnel ram, street motor is 448 ci with ported Stealth's, solid cam and EFI.
What do you guys recommend besides Champion RC9YC and RC12YC.

Thanks

Went to Autolite after many years of NGK...

And after many conversations...


(Heard not so good things about NGK quality control...


Improved things about Autolite quality control...)


Champion out of the question...




First time ever running Autolite...


We'll see what happens...

I have run Autolites for years, even the one's made in mehico with excellent results, switched to NGK's a couple of years ago and have just as good of results with them, standard Champion's used to be a good plug but seem to have gone down hill a number of years ago, I ran the Champion racing plug for a while and had sucess with them too but they are harder to find around here, so I went back to Autolites.

Auto lite for last 10 yes on big blocks. Never an issue. Hated champions

using autolites in my edelbrock heads. cheap, easy to find and burn clean.

What ignition?

Well if you like NGK then use a NGK plug. Probably want a heat range of 7 in the race motor and 6 on the street engine.

I have had less than stellar luck with Champions and Autolites. On 2 different occasions I put a new set of Autolites in a car I'd owned and the engine had a miss immediately afterward. Put the old plugs in and it cleared up.

I've never had bad luck with NGK's, in everything from race cars to lawn equipment.

Champions have always seemed weak for me

Whenever I find Champion plugs in an engine/car I just bought, they always leave the area with a nice large parabolic curve.

autolites on both cars, one has indy heads, and other has 440 source heads. 0 issues and i run the cars rich as [censored].

I would correct the air fuel ratio first, jetting or fuel map, to stop the plug fouling first and go from there I've used all three brands of spark plugs with good results with all of them On your deal with Autolites on the street I would start with Auolite # 3924 resitor plugs or thier # 3911 non resitor race plugs IHTHs

Champions may or may not be better or worse than others. But in my mind; if you're fouling plugs, you have tune issues.

I run Denso plugs in my engine. I had my heads out on the bench at work and had a Tundra in my rack getting a tune up. So I screwed on of the Denso Iridium plugs from the Tundra into my Indy head and they looked good in the chamber. So I snagged a set out of parts just to break in my 493 and surprise!!! they are still in there after about 6 years. They don't foul and never miss a beat EVER!!!
I'll never use another brand plug in my engine.Been using Denso plugs in all my engines since I've been an import technician

Gus

Race car has MSD dist, MSD HVC II coil, MSD wires and MSD 7AL2, street car has MSD dist, Mallory coil, MSD wires and 6AL2.

Sounds like Autolites is what the majority are happy with. Can someone supply me with the part #'s I should use in my race car and street car please. If I don't have full part # for the kid behind the counter I might as well be asking for a fart can muffler for a tuner car!!...:o)

Ive never had any issues with the Champion Race cut back plugs, C59 CX I think? Most misfire problems are either too rich, or to cold of a plug for the conditions.

if memory serves, i run the autolite 3923, and 3924's, one car is 10.15 compression, other is 10.9, both are street/track cars, never foul plugs.

# 3924 for the street car, 3911 or maybe 3910 for the race car Try the 3911 first and go from there Summit stocks and sells them also

AC plugs, anyone for AC? They seemed on par with the Autolites, better than the Champions in my oil burner a couple years ago.

Iridium for my street car, I just took out a set with 115K on them. Replaced with NGK Iridium TT.

R.