I have a 462,12 1/2 comp,over 600 lift roller cam,etc,looking for a good plug to use.
what spark plugs is everyone using?
Adam Loose
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Davey,
Your engine runs on pump gas, right? Just curious why you're running such a cold plug? I ran AR3924s in all my pump gas stuff.
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I have been trying to run AC 41-629 (new number for FR3LS)
I have had at least 5 of them that were bad right out of the box or went bad within short order and still looked like new.
Had a miss last weekend at the track, changed out to a new set, miss got even worse to the point I couldn't stay into it the whole way down. Changed wires, cap, carb, coil, everything to try and find it, and again it was one of this new set of plugs I installed. Put in some Champions as a last ditch effort, and ran like a top.
I will NEVER run one of these AC plugs again. I noticed they are Hecho en Mexico, must not have good QC on them down there....
Just a tip.
I have had at least 5 of them that were bad right out of the box or went bad within short order and still looked like new.
Had a miss last weekend at the track, changed out to a new set, miss got even worse to the point I couldn't stay into it the whole way down. Changed wires, cap, carb, coil, everything to try and find it, and again it was one of this new set of plugs I installed. Put in some Champions as a last ditch effort, and ran like a top.
I will NEVER run one of these AC plugs again. I noticed they are Hecho en Mexico, must not have good QC on them down there....
Just a tip.
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Ken that's the plug AFR suggests, it's a non-resistor compared to the 392x plugs I believe. The motor is a 10 to 1 motor but I do play with different fuels. The plugs have always run pretty clean and looking at the thread discoloration seem to be about right for heat range (about 2-3 threads). Also from what I've read the 393x plugs run in 1/2 step increments so the 32's are 1 step colder then a 34.....
plus....too many Ferds run those 24's.....
Thanks for the info, DaveyKen that's the plug AFR suggests, it's a non-resistor compared to the 392x plugs I believe. The motor is a 10 to 1 motor but I do play with different fuels. The plugs have always run pretty clean and looking at the thread discoloration seem to be about right for heat range (about 2-3 threads). Also from what I've read the 393x plugs run in 1/2 step increments so the 32's are 1 step colder then a 34.....
plus....too many Ferds run those 24's.....
I never pay attention to the threads. I look down into the bottom of the element with a lighted magnifying glass and look where the timing mark is at on the ground strap. I know on the 392x plugs each increment is ~100 degrees going from memory (which ain't always a good thing for me ).
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yes I use the ground strap for timing too. I'm memory challenged myself so I just believe everything I read on the internet...
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8
I have also had good luck with NGK's on my engine.:yes:
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1,794 Posts
http://www.championsparkplugs.com/sparkplug411_manufacturer.asp?manufacturerID=2i have used many different plugs for different aplications..had a 350 with just under 12:1 and it liked hot plugs better than the colder ones,,i ran a champion Rj12yc in that one..they reved the most and lasted longest. the autolights in the replacement were the worst of the bunch,,
But in other aplications the autolights were fine.
Whatever plug i use in my performance stuff i like to cut the ground strap back..i will try to load a pic..this is a standard ACR45ts
As for yours start a step above the coldest and work your way up..I have never liked the coldest plug of the bunch..your results may varry.
You can cut the strap back all the way to the edge if you like..some i have done that way..I think this exposes the flame kernel a tad more..
Any power gain you ask? ..Dont know but i sleep better knowing it aint stock
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This is what Champion calls the "J" gap. A popular plug with point ignitions had the designation "UJ" which was a cut back side electrode with an extra gap, about .020", inside the insulator to raise firing voltage. They worked quite well. Years ago, the Champion rep hung around the bike shop, but I haven't seen him in years.
x2, same plugs in mine since I built 3 yrs ago. AR3924's.
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I have tried the R5671A-7 the plug I was using when I blew the head gasket this spring. So I moved to the -9 with the Alky. When I converted back to the E85 I tried the -8 and it looked just a little too lean to me but I am no expert at reading plugs so I put the -9's back on to be safe. That is what I have been running lately but they look just like they are a little too dark after a run. Hmmm...Eric68 said he likes the AR3933 for our compression on E85 so I bought a set today and set the gap at .028. Hopefully, this plug will be right. Like Davey said they go in half step increments.
Thanks, We have been running the R5671A-10 in a Nitrous set up and they are very easy to read. Im gonna try the -7 in my car on pump.
ChevJ,
I have had my inspection tool for many years and it was supplied by Champion Spark Plug Co. Don't know if Champion still sells them, as things have really changed over there. The tool should be available through Jegs, Summit or your local auto parts store.
As much as I hate to say it being a diehard Chevy guy, I've always used Autolite AR series plugs in my hot rods
Ken,
It is OK to admit that you are using Autolite plugs . . . . Even though Autolite was originally a spin-off of Motorcraft, it is now a division of Honeywell. I figure that since Honeywell is a major supplier in the aerospace industry, manufacturing parts for the space shuttle and Boeing aircraft, their product quality should be pretty good. I have never had a problem with their products and I think the are still manufactured in the USA!
Thanks eg, i'll look around.
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nope...my AR3932's are made in Mexico...but that's almost the USA now...
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I think you have that backwards--Autolite began in 1911; Motorcraft was started in 1972 by Ford.
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thanks guys...
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NGK's Pro-Filer 210 heads
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There's an Autolite plant 15 miles from my house in Fostoria, Ohio. Don't know what part numbers that they make though.nope...my AR3932's are made in Mexico...but that's almost the USA now...
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