Re: Autolite sparkplugs

From: Mike Klinke (LSOMike@email.msn.com)
Date: Mon Oct 30 2000 - 16:41:10 EST


Henry LaViers, over on the Dodge Ram Truck List just recently posted a
rather informative "Spark Plug FAQ last week. It has a paragraph on the
Autolite plugs and notes that the extended length has a slight timing effect
when compared to the non-extended version. Here's the entire FAQ for your
reading pleasure. Thanks Henry!

Regards, Mike Klinke

-----------------------------

Here 's the latest revision to the Sparkplug FAQ,
with new info on plugs for 4.7V8s,
and some additional info on the NGK ZFR5F11's
that Kenne Bell says tested out as best for the 5.9V8 on their road dyno.
-HankL
----------------
RAM 4.7/5.2/5.9 V8 Magnum PLUGS
================

Champion RC12YC is the 1993-1998 factory installed plug.

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

Champion RC9YC is an even colder heat range available locally,
or Champions can be got by mail order from
http://www.edelbrock.com

Champion RC12LC4 is a longer projected nose plug used on some V8 Rams since
approximately 1998.

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 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.

Champion RC12MCC4 are stock in the 4.7 Magnum V8.

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 condition center electrode metal rod is longer, and
the insulator is black color instead of white.

http://www.federalmogul.com/products_main/am_underhood/ignition_spark_plugs.
ht
m

another better Champion sparkplug site at:

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

Kenne Bell company says they did extensive research and testing on their
in-house DynoJet 145C, and recommend the "V" design
NGK ZFR5F11 (stock number 2262) 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. 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. {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.

http://www.ngksparkplugs.com/

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.
     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
is also widely available.

Bosch Platinums (old style, not +4's) FR8DPX, P/N 4102 (gap .044)

Bosch Platinum FR7DPX p/n 4202 is a similar but colder heat range plug.
{these are 'fine wire' tip sparkplugs that seem to give exceptionally
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/autoparts.asp?sgp=2

Bosch Platinum Super+4, P/N 4418
This 4 ground electrode plug with a platinum "fine wire" center is presently
being heavily advertised, but is not recommended by Bosch for:
truck,
heavy towing, or
"high performance/racing" applications.
The +4 plug is said to be designed for reduced number of
misfires, excellent 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

     In a 1995 5.9V8 Magnum the Bosch+4 seems to give quick cold
starts, smooth idle - 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.
{there is also a 5/8 inch hex version of the +4, P/N 4478}

http://www.boschusa.com/index.asp?div=2&sud=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 part number 7562

Bosch Tech support: 800-521-5462

Autolite Double Platinum Pro APP3924
(APP3923 is a colder heat range platinum plug)

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
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

AC Delco Rapid Fires, P/N 5
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 3LDOHC. In a manner similar
to
the NGK V design, the AC Delco Rapid Fire P/N 5 has 'gear teeth' cut into
the
center electrode to create more sharp edges for the spark to jump from.

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

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)

-------------------------------------------------

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.
-------------------------------------------------

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 dumped
into it.

------------------------

-----Original Message-----
From: jay & dana <jay&dana@telus.net>
To: DML <dakota-truck@buffnet.net>
Date: Monday, October 30, 2000 3:06 PM
Subject: DML: Autolite sparkplugs

>I was at the auto parts dealer today and checked out the Autolite 5224's
and
>3924's. The only visible differences seems to be that the 5224's extend
>slightly further into the combustion chamber. Why would this be a
>"disadvantage" over the 3924's for a 318 application? Would appreciate any
>response.
>
>Thanks
>Jay
>
>



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