Spark plugs
 

SPARK PLUGS
What kind do you run & why?
How often do you change plugs?

Re: Spark plugs
 

Champion---they produce a tad more HP than the Autolites (dyno proven)- Changing frequency depends on the situation-FED 387

Re: Spark plugs
 

I see MSD is in the spark plug business now,,, anybody try these yet? I'm just thinking of different options in the off season right now for us in the rainy NW.
Danny Durham

Re: Spark plugs
 

I was running Champion, RC12YC, but they're getting hard to find, and the racing version is near impossible to find. Trying some AC Delco plugs soon.

Re: Spark plugs
 

I use AR-13 with great success.
Terry K

Re: Spark plugs
 

I have been using the AC Rapidfires for years. I like them.

Re: Spark plugs
 

Champion N9YC ( 300 New # ) in small Mopars.
I liked Champion N63YC but have not found any
for a couple years!

Anyone have a good Big Block Plug for stocker.
Autolite AR seem to have been changed vendors last
couple years and we have had difficulties since then.

Re: Spark plugs
 

Careful with Ac/delco, it is not the company it once was :rolleyes:
Lots of pirated off shore stuff kicking around. I went to NGK and never looked back.

Kevin

Re: Spark plugs
 

Alot of the AC plugs are now made by ngk .The champion RC12YC is available in probably every parts store that stocks champion .

Joe

Re: Spark plugs
 

The RC12YC is not nearly so commonly available as it once was, and for some reason, many parts stores do not stock Champion, or many Champion part numbers, any more.

Re: Spark plugs
 

They should be avail at any Carquest/Advance auto.Also from what i have seen I think brisk now makes accel plugs.


Joe

Re: Spark plugs
 

I'm not familiar with the racing version, but RC12YC's are everywhere, I agree with jcw31.
It's a very common plug in many Briggs and Stratton and Kohler lawn tractor engines.
A quick Google shows many sources:
https://www.google.com/search?client...UTF-8&oe=UTF-8

Re: Spark plugs
 

The CarQuest stores here are few and far between, and can be hard to get by when they're open, and Advance stores here no longer seem to carry them. If they did, I'd have them. Both of our aluminum head big block engines can use them.

Re: Spark plugs
 

http://www.clubplug.net/

Alan how about this?

Re: Spark plugs
 

Alan. Dont you you think that is a warm heat range for any high rpm/compression motor. Ive seen some high end s/ss builders using a cold as ar3932/c59c on 396/325 combos in stock?

Joe

Re: Spark plugs
 

Alan, how about 24 of them for $40?
http://www.ebay.com/itm/like/360396277454?lpid=82
Or any outdoor power equipment shop. Like I said, they're used in lawn tractors.

Re: Spark plugs
 

They do not exhibit any signs of temperature or detonation problems in my engines.

Re: Spark plugs
 

Alan, I am pretty sure I picked them up at Wal-Mart might want to check there...

Re: Spark plugs
 

There's an old urban myth that plugs in blister packs sold in dept. stores are somehow inferior to ones at auto parts stores. Any truth to that?

Re: Spark plugs
 

Alan, one of the best places to procure spark plugs is at: www.sparkplugs.com

It appears they carry 3 different types of the RC12YC plug.
http://www.sparkplugs.com/SearchResults.aspx?kw=RC12YC

They also carry racing plugs.

Re: Spark plugs
 

With many things that are manufactured, there are varying acceptable quality parameters. When one manufacturer makes the same product for many companies, each company can have its own acceptable quality window.

Realize that this is intentionally vague and simplified:

Company A says they'll take x,000,000 parts, at price point 1, and their acceptable quality window is >....................<

Company B says they'll only take x00,000 parts, at price point 3, and their acceptable quality window is >.......<

Now, company A will sell that product for $1.00, selling 10 times as many as company B, and accepting a relatively high warranty rate.

Company B will sell the same product for $1.75, selling less, but having a relatively low warranty rate.

You can often go to a big box store and see that they have cheaper prices, but then look closely and find out the product is made cheaper, and often it is made cheaper because the big box store has the buying power to convince the manufacturer to make a lesser quality product to sell at a lower price point, but in a higher volume. And they hope that the consumer will simply decide the product is so cheap that when it fails, they'll throw it away and buy another rather than deal with the hassle of warranty.

Now, about 20 years ago, I had a guy from a major automotive parts supplier tell me that they actually had five tiers of parts. Tier 1 was OE, best quality, tier 2 was new car dealer, tier 3 was "professional" parts houses (at the time, NAPA, Carquest, J.B. Cook, etc) tier 4 was cheap parts stores (Autozone, Advance, etc) and finally tier 5 was Walmart/KMart, etc. At the time I was working at a high end shop that was in a building shared with a "professional" parts store that was actually owned by a company that was a warehouse distributor for an OE parts supplier.

I'd say at least a couple of those tiers may have gone away. The "professional" parts stores are getting fewer, and the Autozone/Advance stores more numerous and powerful. At this point, it is possible that the OE and new car dealer tiers are now one and the same, as are the "professional" parts store and the Autozone/Advance tier are likely one and the same.

Re: Spark plugs
 

I just bought 2 sets of AR 23's..Maybe they were 24's....Put them in and had a miss..Went to put second set in and found the porcelain and the terminal stud in two pieces. It was all together, but when I tested the collar to make sure it was tight, it just spun freely and when I turned it upside down the metal guts just fell on the floor.. Poor quality,,,,,,,, Junk ..

Re: Spark plugs
 

Not plugs, but, I once worked for a company that made lights for GM. There was one standard for assembly line headlamps and tail lamps and then a lower standard for service parts .

I also had a salesman tell me the same thing about fan belts he sold, box stores had next to no quality inspections and looked after their own warranty. Big box stores bought them cheap and hoped the guy never came back for warranty.

Manufactures that sell the stuff with out warranty on their part love it as there are no headaches later.

Re: Spark plugs
 

Where I work we sell alot of champions to some chrysler dealerships, ne ver had any problems with quality. The only thing i know is in the mass merchandisers they take care of their own warranty which in turn the mfg. gives a deeper discount so they can sell cheaper and make the same or more profit. Also alot of autolite is now made in china.

Joe

Re: Spark plugs
 

Thanks Alan, I had no idea the same item could be made into several "grades", again, thanks for that eye opener

Re: Spark plugs
 

Years ago I was at a Glad plastic factory. They also made "store brand" plastic bags and wraps, etc. It makes sense. They already made the investment in all of what it takes to produce the product.

Alan, we've pointed out several places to get RC12YC's. Are you saying that the "tier 1" RC12YC plugs are not available? I'm confused.

Re: Spark plugs
 

Anyone understand the difference between the three different RN12YC?

Is there any reason on running a resistor style plug on a Drag Car?

Re: Spark plugs
 

If you have no electronics (EFI, data loggers, etc), metal plug wires and non-resistor plugs should be fine.

Re: Spark plugs
 

I run NGK R5671A-8 4554 Racing spark plugs, in my SB Olds...

Re: Spark plugs
 

I run Autolite AR 3910's in aluminum headed SBC

Re: Spark plugs
 

Sorry to scare you guys off asking about MSD spark plugs,,, I know they're fairly new. Perhaps no one has tried them yet? Maybe they'll pay contingency. Just wondering.
Danny Durham

Re: Spark plugs
 

I have purchase 3 set of AR-13 plugs this season and each set has been in the engine and iI check my plugs after every race that I have attended and after every race there was a problem with at least one plug mostly the porcelain was cracking.The saving grace of it all was NAPA took back each bad plug and gave me a new one.

Re: Spark plugs
 

I have purchase 3 set of AR-13 plugs this season and each set has been in the engine and iI check my plugs after every race that I have attended and after every race there was a problem with at least one plug mostly the porcelain was cracking.The saving grace of it all was NAPA took back each bad plug and gave me a new one.

That is interesting.I have never had an issue with my AR-13 plugs.

Re: Spark plugs
 

Most problems are from over tightening the tapered seat plugs'

Re: Spark plugs
 

to MEXJOE and Alan sorry for going a little sideways but i am not sure there is a good or bad plug.I dont think these companys take the time to sort plugs for different tiers ,too costly. Ive seen on the dyno v59yc,ar3910
Autolite,r5671a-8 ngk all were within 1 hp .When Autolite came out with their ar racing plugs we were using 23s changed to ar 13 driver came in after the heat and said plugs were garbage went back to 23s and was happy. In a small block mopar drag car ran n9yc champ tried 63 autolite car slowed .05 .I saw a 440 mopar on the dyno 414s accels egt was good a/ f was good 1st time out 2runs the plugs were peppered like crazy. I believe plugs from different companys even though crossed to the same the heat range is a little different.
Alan if you need rc12yc pm, me. I think with any plug unless extremely cold or hot, just changes in timing/jetting can make the engine happy.

Have a happy Thanksgiving everyone
Joe

Re: Spark plugs
 

I do not know for sure how much testing and sorting they do these days, seeing what gets sent out in a box often leaves me thinking there's not much QC at all any more. They have to do a fair amount though, because the cost of shipping a lot of bad plugs to an OE would be tremendous.

Despite using the hotter RC12YC, my jetting, timing, and even air bleeds are real similar to Jimmy's tune up, and they make close to the same power, being very similar engines.

A hot plug might cause a problem in a circle track application, where it had plenty of time to get really hot. However, in a drag race engine that leaves the starting line at 100 F, and is barely 160 F at the finish line 10 seconds later, you'd need a really hot plug to have a heat range problem.

Re: Spark plugs
 

What Alan says, I,ve used hotter plugs in my engines for years. Was told to do this by a well respected engine builder.

Re: Spark plugs
 

Alan and Lee I agree with you . As Billy said AC rapidfire also champ autolite ngk or whoever all work great. I dont think theres any magic in plugs be it high $$$ or 2$ . The autolites i referenced were supposed to be the same heat range [ar13 vs 23] but they didnt perform/ feel the same at the time for the driver.

Thanks Joe

Re: Spark plugs
 

I finally took the time to "back-to-back" sparkplugs on Saturday and I was a bit suprised at my findings. When I put the car together, I put in the least expensive plugs that W-Mart had. Just basic plugs. I did an A-B-A-B test between them and a set of iridium plugs that I have used in some of my other stuff. So can a $16 set of plugs perform as well as a set of $64 plugs? Not quite, the iridium plugs averaged .034 ET. and .3 MPH faster than a basic plug. Are they worth the extra $48? In a heads-up or qualifying situation I guess they are. You decide.


For what it's worth, this is from my "Under the index for under a grand" thread. The base plugs were Autolites and the good plugs were AC Rapidfires. Are plugs worth the same in a real good HP engine as they are in a not-so-good lo-po engine? I can't answer that.

Re: Spark plugs
 

Of note, the AC Rapidfire is a "broad heat range" plug, they're designed to heat up fast and clean off, without getting too hot. Back when they were first introduced, the AC rep who taught the classes I mentioned in a previous post gave us plenty of back ground on them. This may in fact be a really good thing for a race car, considering the amount of time they spend idling and at low speed, as well as being started relatively cold. Add to that the fact that a lot of people set their idle mixture fairly rich, and you can see where a plug with the design attributes of the Rapidfire might help. Having used them in various applications over the years, I'm not convinced the current version is as good as the original version of several years ago. I have however seen them last as long as or longer than the high dollar "precious metal" plugs, and perform as well or better, in many applications.

Smokey Yunick once told me "if you knew how many times your engine actually misfired, you'd be so pissed off, you'd never start it again". What a lot of people don't understand is that most of the noise you hear is from air flow, not actual combustion. Yes, you can hear a dead cylinder easily. But as Smokey once demonstrated, and backed up with data, what you can't hear is how often each cylinder has a partial misfire. I don't think you can solve that problem with trick spark plugs, or trick spark plug wires. I do think you can make the problem worse with the wrong spark plugs. I don't think any one company makes the best plug, or the best plug for all applications.

It should be understood that most of the "precious metal" content in spark plugs is not for more, hotter, or better spark, but rather for longevity, allowing the OE to reach closer to the unrealistic "100K mile spark plug" that is pretty much required by the current emissions standard. It should also be understood that while the "100K mile without a tune up" is a good marketing ploy, what it actually means is that the "tune up" will merely meet the emissions standard at 100K miles. It does not mean that the parts are actually giving you the best performance and economy for 100K miles. They are not. They start to really degrade past 50K. Even if the plugs do not show severe gap erosion, they will show significant build up of deposits.

Odds are, long before you see any of the actual advantages of the "precious metal" plugs, you'll have swapped them out for fouling, deposits, or just habit.

The above is sort of a long way of saying I'm not sure you'll see much of a gain with expensive "precious metal" spark plugs in most race engines. There may be the odd application where you do. However, if you have a good hot ignition system and top quality plug wires, a good set of copper core spark plugs (with the resistor) is probably good enough. Without that resistor, you can end up with "noise" that can cause high end ignition systems (MSD, ICE, etc) to have odd behavior. It could leave you chasing a misfire or flutter for quite a while.

Last, there can be some gains to the "fine wire" center electrode. They warm up fast, and they tend to concentrate the spark kernel.

The rest of the trick stuff, multiple ground electrodes, trick ground electrodes, trick center electrode tips, don't seem to show any gains, and often show losses.