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Autolite Platinum Spark Plugs? Or not?

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Spark Plug Time!! Need Help!!

14K views 15 replies 6 participants last post by  marcp365 
#1 ·
Well it's time! Time for new plugs that is...

Lets have it... What does everyone think of AutoLite Platinum plugs? Gimme what ya got ladies & gentelmen... :flippy:

Please give it up soon, I gotta get the newbes in next weekend..

Tanx everybody :cheers:
 
#2 ·
I'm running NGK ZFR5F-11 spark plugs, and I love them. They are gapped at .040 and I felt a nice increase in throttle response at all speeds. I highly recommend them. Part # is 2622 I believe.
 
#3 ·
Thanks for your reply

Thanks for your imput. I'll check them out. :D

Tanx :cool:

P.S. Nice list of mods!! :tup:
 
#5 ·
Thanks for your reply..

Oh Lucifer, don't suppose you have part numbers for those... Do ya, do ya, huh? :IDEA:

Tanx :D
 
#6 ·
I'm using the Autolite 3923s and couldn't be more pleased. Planning on trying the Autolite 3922s, due to a pinging problem.
 
#7 ·
Thanks for your reply...

When you refer to the number "3923", is that the Autolite number? I picked up the Autolite Platinum’s and they have a 5000 series number (Don't remember the exact number), after everyone keeps posting these other numbers, I'm thinking of returning the set I got and hunting down the others.

What do you think??

Tanx :D
 
#8 ·
Yes, 3923 is the product/model number of the spark plug. Would the model number of your 5000 series spark plug be 5224 ? I believe that would be the Autolite stock equivalent spark plugs.
 
#9 ·
Here's another update to the Sparkplug FAQ.

Some new info on internal resistances of plugs in ohms. There is quite a difference between certain plugs.
Also some new info on the Brisk plugs featured in one of the Mopar magazines recently, and some info on gap size selection and ignition wires at the end.
==========

What sparkplugs will fit a Magnum engine in a 1994+ Ram or Dakota pickup? ' Here are some sparkplugs that will fit with brief comments.

Where a resistor value is given, it was measured by the author from terminal top to center electrode tip using a Fluke 87 multimeter.

RAM 4.7/5.2/5.9 V8 Magnum PLUGS
=======================

Champion RC12YC is the 1993-1998 factory installed plug. (resistor inside measures 75,000 ohms)

Champion RC11YC is one heat range cooler and is part number 3344.

Champion RC9YC is an even colder heat range available.

The Champion RC9YC4 sparkplug has been reported by Ram owners as being helpful in reducing pinging.

Champion RC12LC4 is a longer projected nose plug installed at the factory on V8 Rams since approximately 1998. The plug change was probably for emissions purposes.

Champion RC12LYC is a longer 'projected nose' plug previously recommended for the Viper alum. V10 and Chrysler 3.2/3.5L V6's.

The '95 stock factory sparkplug for the iron block Dodge V10 engine was a Champion Copper Plus RC9MC4.
The 1995-1999 iron block Ram V10 is a QC9MC4, where the Q instead of the R means the resistor inside is a "wire wound" instead of the SAC semiconductor that Champion primarily uses to surpress radio interference.
An email to Champion in 1998 got a reply that the '9' in the above numbers does mean that these plugs are 3 heat ranges cooler than the '12' heat range plugs like the RC12YC used in the V8's.

Why the truck V10 uses a 3 heat range cooler sparkplug is not known, but perhaps since the heavy trucks don't have to meet as stringent pollutions standards, this is a more ideal sparkplug for performance instead of emissions.

Champion RC12MCC4 are stock in the 4.7 Magnum V8.

Champion RC10PYP4 is a projected tip, double platinum plug that is standard equipment in some of the Chrysler 2.5L V6's that have 3 almost impossible to reach plugs in the rear. Being two heat ranges cooler with double platinum tips for long life it might be an interesting replacement for the Magnum V8's.

Champion Truck Plugs P/N 4071
Many Ram owners have reported they were pleased with a change to this plug. The main differences between the Truck Plug 4071 and the stock RC12YC seems to be that the new center electrode metal rod is longer, and the insulator is black color instead of white. (Resistor inside 85,000 ohms) It is possible that the extra 10,000 ohms of resistance retards spark firing a little bit, and may account for why some report that this plug reduced pinging on their Ram.

http://www.federalmogul.com/product...spark_plugs.htm

another better descriptive Champion sparkplug website at:

http://www.edelbrock.com/automotive/sparkplugs.html

If unavailable locally, Champion sparkplugs can be mail ordered from
http://www.edelbrock.com

Kenne Bell company says they did extensive research and testing on their in-house DynoJet 148C, and recommend the "V" design NGK ZFR5F11 (stock number 2262, resistor inside 4,000 ohms) for non-supercharged,
and ZFR6F11 (one heat range cooler) for blown 5.2/5.9 Dodges.

These V design NGK sparkplugs have a v-notch cut into the center electrode that increases the sharp edges and moves the spark away from the center. Sharp edges reduce the voltage need for the spark to start. The nose of these plugs seem to be slightly more projected than the Champion RC12YC. The ZFR5F11 is also NGK's recommended Viper Aluminum V-10 plug.

One Ram owner reported on MoparChat that he purchased 12 of the ZFR5F11 plugs and "indexed" the 8 that 'by chance' stopped in the threaded hole with the ground electrode post toward the fender side of the truck. This puts the open gap toward the valves and is done that way in hope that it would aid combustion speed. Increased combustion speed is generally a good thing, but if the engine is already pinging this may increase detonation tendency.

If you put a piece of white tape around your sparkplug socket and make a black mark on the tape, it is easy to insert the plug so that the ground electrode post is lined up with the mark. this way you can see where the ground post ends up.

These ZFR5F11 plugs were reported to noticeably pep up the 5.9 V8 engine compared to the 30,000 mile old Champion plugs. See this webpage for an article on indexing with good pictures:
http://www.fordmuscle.com/archives/...ugs/index.shtml

NGK's standard recommended sparkplug for the 3.9/5.2/5.9 Magnum engines is the FR4 (stock number 5155) or FR5-1, (stock number 7252).

http://www.ngksparkplugs.com/products/cars_trucks_suvs/

NGK has a very good set of pictures for reading the ends of used sparkplugs at:

http://www.ngksparkplugs.com/techin...aq/faqread2.asp

Mopar Performance now recommends and sells Bosch conventional metal tip sparkplugs in their 2000 year catalog for mopar engines, and gives a table of interchanges on page 125.

The Mopar Performance plug (Mopar Perf p/n P4876926) from the catalog for Magnum 5.2 or 5.9 V8 engines {also A engine and Hemi} is a repackaged Bosch FR8DCX, Bosch part number 7557. (Resistor 5,600 ohms) Note the 'C' in the DCX that indicates a copper core center electrode tip rather than the 'P' that indicates platinum. Mopar Perf lists the 'retail' price of this plug as $12.50 for a pack of 4. Parts Plus auto stores sell one Bosch p/n 7557 for $2.02 plus tax. Some Napa stores have the 7557 at $1.22. Several Ram owners report good performance from switching to this plug.

Bosch also makes a sparkplug with a longer projected nose similar to the Champion RC12LC4 that is Bosch part number 7562 with descriptive number FR8LCX. There is also a FR8DC (part number 7527) that comes with a smaller pre-set gap.

If you need a colder heat range plug, the Bosch FR6DCX (part number 7553, Resistor 5,500 ohm) is also widely available.

Bosch Platinums {old style, not +4's}
FR8DPX, (part number 4102, Resistor 4,700 ohms, gap .043)

Bosch Platinum FR7DPX p/n 4202 is a similar but colder heat range plug. (Resistor 6,600 ohms) These are 'fine wire' sparkplugs with surprisingly tiny tips that seem to give quick cold starts and good mpg on Interstate driving. Increased gaps up to 0.050 from the Bosch factory setting of 0.043 seem to work ok.

http://www.boschusa.com/Consumer/Automotive/SparkPlugs/

Bosch Platinum Super+4, P/N 4418 (Resistor 3.6 kohms)
This 4 ground electrode plug with a platinum "fine wire" center is presently being heavily advertised, but is not recommended by Bosch for:
(1) truck,
(2) heavy towing, or
(3) "high performance/racing" applications.
The +4 plug is said to be designed for reduced number of misfires, low emissions, and is said to be durable enough to last for 100,000 miles.
There is a brief article on this sparkplug design at:

http://www.babcox.com/tr/tr119832.htm

NGK also makes multi-ground sparkplugs and calls them the 'Multi Power' design. Here's how NGK describes their good/bad attributes:

"NGK Multi Power Spark Plugs
NGK Multi Power Spark Plugs feature multiple ground electrodes for extra-long life in a variety of applications. Spark plugs wear out when the sharp edges of the ground electrode round off. Therefore, multiple ground electrodes provide additional surfaces for the spark to travel to, extending the plug's effective life. Multi Power Plugs are not for all applications, as they can tend to quench the spark, or hamper the ability of the flame to grow from the initial ignition point. However, the multiple ground electrode configuration can help alleviate a number of problems, including hard starting, excessive fouling or misfiring. They are also effective for vehicles with very high ignition system voltages and/or combustion chamber temperatures. Remember that Multi Power Spark Plugs, or any other multiple electrode type spark plug, cannot provide more than one spark at a time. The primary purpose of the multiple electrode spark plug is to achieve greater spark plug durability and reliability over the life of the spark plug."

In a 1995 5.9V8 Magnum the Bosch+4 seems to give quick cold starts, and the smoothest idle of any plug tested - but this plug seems to be prone to increased pinging, perhaps because its large gap (0.065 inches) and long projected nose may be equivalent to a slight ignition advance. This is not the plug to try if you have a Mopar Perf computer already installed or insist on using 87 octane all the time.

Bosch advertises increased MPG with this plug, but Consumer Reports found no mpg difference when compared to factory NGK sparkplugs on a Honda. 1995 Ram 5.9V8 owner on four 300+ mile test runs over same stretches of Interstate 95 from NC to FL found 2% worse mpg with Bosch Super+4 plugs going northbound compared to going southbound with Bosch FR7DPX gapped at 0.050 inches.

There is also a version of the +4, part number 4478 with the larger hex size of older sparkplugs. The heat range of this plug is not known.

http://www.boschusa.com/index.asp?d...d=1&grp=1&sgp=1

For the 4.7 V8 Magnum,
Bosch recommends the part number 4230 regular single electrode Platinum or the copper tipped Bosch Super Cu part number 7562

The Bosch F6DP spark plug
(part number 4227, resistance from tip to electrode 1,400 ohms) has been recommended by engine guru Larry Widmer as a good plug for supercharged applications.
In a 1995 5.9V8 these F6DP plugs seem to work as well as the FR8DPX if the gap is increased from 0.025 to 0.043 inches.

The missing 'R' after the F indicates this is one of the few Bosch platinum plugs that does not contain a resistor for radio interference surpression, even though when measured with an ohmeter a F6DP still read a resistance from top terminal to electrode of 1,400 ohms versus the 5,500 ohms of a FR6DCX.

The pre-set factory gap of a F6DP is a small 0.025 inches, which is advantageous to reduce misfires when cylinder pressures are very high. The 6 in the F6DP indicates this plug is two heat ranges cooler than the FR8DPX that Bosch literature says cross-references to the Champion RC12YC that comes from the factory in Magnum engines.

Bosch Tech support: 800-521-5462
-------------------------------------------
Autolite Double Platinum Pro APP3924
(APP3923 is a colder heat range platinum plug)
The two P's indicate two platinum nibs on the electrodes where the spark jumps.

Autolite 3924 or cooler 3923
Many Dakota owners who drag race their trucks recommend this relatively inexpensive plug, and some claim to have chassis dyno results showing 4-5 hp improvements. Many use this plug with the MP computer and a 180 degree thermostat. See dyno graph at this site:

http://www.fast4x4.net/dyno.htm

Autolite 5224 conventional metal tip (Resistor 5,400 ohms)
Autolite 5223 is a colder heat range plug
The 522? series is similar to the 392?, but has an extended tip that puts the spark farther down in the chamber, which has an effect similar to slightly advancing the ignition timing.

http://www.autolite.com/products.html

Autolite is advertising a new plug called the 'Titanium' that has two platinum nibs but no titanium parts.

---------------------------------
AC Delco Rapid Fires, P/N 5 (Resistor 3,700 ohms)
Some Ram owners report the Rapid Fire plugs give a smoother than stock idle, and the p/n 5 is supposed to be a 'one-size-fits-all' relatively cool heat range that is also the same plug recommended for the Dodge Stealth turbo V6 3Liter DOHC. In a manner similar to the NGK V design, the old style AC Delco Rapid Fire P/N 5 had 'gear teeth' cut into the center electrode to create more sharp edges for the spark to jump from, but this plug was recently designed and looks more like a conventional plug now.

GM did hire an independent firm to test these sparkplugs in fleet use, and some mpg gains and idle smoothness improvements were reported to be found.

http://www.acdelco.com/parts/1380b.htm

The standard ACDelco sparkplug for the 5.2/5.9 Magnums is the FR3LS
Here is a webpage on how to decode ACDelco sparkplug numbers:
http://www.acdelco.com/parts/sp_ident.htm
--------------------------
Motorcraft
The standard copper Motorcraft sparkplug for the Magnum V8 is a AGSP32C. A longer projected nose plugs is the AGSP32CF4.

Motorcraft also offers a double platinum tipped AGSP32PP.
-------------------------

In the Splitfire Catalog it specifies that a 5.9 Magnum V-8 uses different plugs for different years:

A '95 360 uses plug "SF392D" with a .035 gap
A '99 360 uses plug "SF522D" with a .040 gap
------------
Torque Master, P/N VFN8BR ($12.50 per plug)
--------------

Unusual Czech-designed surface gap sparkplugs from the Brisk company:

http://www.brisk.cz/uk/default.htm

The DOR17LGS is the plug model recommended by Brisk for the 5.2V8 in the Jeep Grand Cherokee.
-------------------------------------------------

Switching to larger hex (old style) sparkplugs from the 'peanut' plugs used on the 1992+ Magnum engines:

If the heat shields around Magnum engine sparkplug holes are removed by gently squeezing them with channel lock pliers, Champion 'N' series sparkplugs with the 5/8 hex nut flats can be fitted to 3.9V6/5.2V8/5.9V8 Magnum engines, but a special sparkplug socket must be ground down on a grinder to a small enough diameter to fully tighten the sparkplug - otherwise an unmodified sparkplug socket will hit the hole designed to retain the now removed heat shield. A cheap stamped metal 'lawn mower' sparkplugs socket works well for this. Some prefer to use N series Champion sparkplugs because a wide variety of heat ranges are available, and many old time drag racers have built up a body of knowledge about these plugs.
-------------------------------------------------

The Dodge Stealth 3.0L V6 DOHC Turbo "trick" to find a colder heat range sparkplug for your Ram pickup when dealing with non-knowledgeable parts counter attendants.

If you want a colder heat range sparkplug, because you aggressively drive your truck and keep the throttle more wide open than most, you can find a colder range sparkplug by asking for one for a 1995 Dodge Stealth 3.0L V6 Double Overhead Cam Turbocharged engine. Sparkplugs recommended by any sparkplug manufacturer for this application are 1-2 heat ranges cooler than the factory Ram sparkplugs, but these 'Stealth' plugs are the same physical size.

Warning: colder heat range sparkplugs foul easily, quit sparking, create more pollution, and give lower mpg when the engine is not driven at wider throttle openings frequently to burn away carbon deposits. This can also cause hard cold starting and a miss at idle. Prolonged running of an engine with fouled sparkplugs can overheat and ruin a catalytic converter that is getting unburned gasoline & air dumped into it.

Spark Gaps:
A typical spark gap of the past was about 0.025 to 0.035 inches. Larger spark gaps help idle quality, decrease total burning time like an ignition advance, and may improve miles per gallon slightly.
However, larger spark gaps are harder to get to spark. On most engines too large a spark gap usually shows up as problems at rpms over 3500 rpm, where there may be a miss and vibration, or alternately a
miss-ping-miss-ping-miss-ping. At high rpms the vibration you might expect to feel from a miss can be masked by the short times between firings.
How can a miss cause a ping? Usually a cylinder's fill after a stroke is about 80% fresh mixture and 20% left over exhaust gas. When a miss occurs the next stroke results in a cylinder fill that is about 100% fresh air and fuel. Sometimes this extra fill results in such a faster and forcefull burning that a ping occurs.
When is doubt, use a sparkgap of 0.030. Then slowly increase the gap until problems are detected. The more powerful you make your engine with mods, the less sparkgap you should set, because high cylinder pressures at high rpms need less spark gap. If your engine is pinging it is usually worth while to set the gap at 0.030 inches and see if that changes anything. the small gap decreases the chance of missfire and also acts like a slight ignition retard.
For the Magnums, recommended spark gaps have ranged from 0.035 on 1994-1996 Magnums with Champion RC12YC to 0.040 on the RC12LC4 to 0.065 inches on the Bosch Platinum Super+4 pn 4418.

Ignition wires:

Magnecor ignition wires are of very good quality:

http://www.magnecor.com/magnecor1/Index.htm

In addition to the regular style Magnecor, the "CN125" wires are very good at surpressing radio noise for Ham, scanner or CB. The FAQ section at Magnecor is 'no bull' and worth a read. These wires retail around $110 but
can be found for less.

Magnecor admits in their write-ups that NGK ignition wires are of good quality:

http://www.ngksparkplugs.com/techinfo/wire_sets/

MSD makes wires whose internal construction is perhaps a slight step down due to their falling into the
"Low DC resistance impresses Uninformed Customers"
advertising wars.

In ignition wires, it is the 'impedance,' not solely the ohms of resistance, that determines voltage drop and current.

MSD#32189 is the 94-97 Ram 5.2/5.9L V8 Wire set. MSD 8.5 mm wires on a 1998 5.2/5.9 L are part number 32979, and cost at Summit is about $80 with postage.

Champion has a line of 'Truck Wires' they came out with last year that look pretty good and have a heat resistant ceramic boot at the plug end. For the 5.2/5.9 Dodge Magnum, the Champion TruckWire part number is CHA69417 and is available thru Napa stores.
 
#11 ·
Tanx for the replies!!

WOW HankL, that's amazing! Thanks... :STY:

Hey McClane!! What do you think about that post you hooked me up with? Stay away from platinum plugs? Aren't the 3923's platinum? What do ya think?

TanX :D
 
#12 ·
Thanks for all your help!!

Well, after much deliberation I decided to go with the NGK ZFR5F-11 spark plugs. I plan to install them on 4-27 next Saturday, along with my new Gibson 3" cat back system & cut out. :cool:

I'll be sure to let you all know how it turns out...

Thanks again for all you help everybody!! :D
 
#13 ·
I had not noticed until now that you have a 4.7V8.

Most of the comments in the Sparkplug FAQ were from gathering info about the 3.9/5.2/5.9 and V10

As far as the 4.7 is concerned I have not heard from anyone who has installed the NGK ZFR5F-11 in the newer smaller V8.

On the Dakota list there have been favorable comments in past posts on DML about using the Bosch+4 plugs.

The 4.7 ignition timing appears to have been retarded a fair amount, and the Bosch+4 seems to give a slight 'advance' that is noticeable.

The cylinder heads of the 5.2/5.9/V10 are the same
but the 4.7 is very different, so there is no technical reason why they should "like" the same plugs





My experience in a older 5.9V8 with the Bosch+4 over about 20,000 miles and several MPG tests showed no advantage to them - but I did find that the Bosch+4 plugs gave extremely good start-ups and I think I could feel that the +4s had a little more low end torque.

Anyway, be sure to give us a full report about whatever plug you install in the 4.7

I need additional reports to update the Sparkplug FAQ in the 4.7V8 area.
 
#15 ·
4.7L "D"

You bet I will... I'm very interested to see how it comes out.. Anything has to be better than stock!! LOL

Thanks for the great info... :STY:
 
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