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  #1  
Old February 17th, 2004, 20:57
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Kejtar Kejtar is offline
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Talking Plugs.... plugs... plugs

OK, I did the customary search and I didn't find what I was looking for: Is there more then one type of a sparkplug that the dealer offers?? I remember a mention of a better plug then the standard one....... and on the same note what are you guys using? Currently I have bosch 4+ and I got no complaints, but since change is good what else is out there?? I know that most recommend champions but is there anything else worth attention?
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  #2  
Old February 17th, 2004, 21:12
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JeepFreak21 JeepFreak21 is offline
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Butt plug?
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  #3  
Old February 17th, 2004, 23:17
billboarder billboarder is offline
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do not use champions. do not use splitfire. champions are crappy and splitfire arent worth the money. after many trials im on to the bosch now and am very pleased.
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  #4  
Old February 17th, 2004, 23:24
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Bloose Bloose is offline
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Plugs have one job, start the burn of Air/fuel mixture in the combustion chamber. Once the mixure is ignited the plug can do nothing more to increase power, period, burning is burning. I am not a fan of funky plugs or even MSD boxes on stock applications for this reason. But I am a fan of platinum plugs and plugs of other types of metals. Not because they will make you motor run any better but because they just plain last longer. Every time a plug fires, a tiny piece of the electrode and ground strap go away. With the platinum plugs they resist this much better and therefore last longer. In extreme applications, which stock Jeep motors are not, there may be a need to increase spark duration (and energy) and/or expose more of the spark to the fuel mixture (Side gapping). Examples are the use of exotic race fuels, NOS, etc. In cases like these where the fuel may be difficult to ignite and motors run at high RPM MSD boxes and and special plugs may produce big gains. Also plugs for these applications may be made to endure a much harsher enviroment than a normal plug.

All that being said I have only two recommendations. One stay as far away from Split Fire's as you can. Splitting the ground strap causes the metal in that area to have less resistance to heat and can actually glow and cause preignition. I've also heard U groove and V groove plugs can do the same but are not as extreme. Two, stay away from Champion. Everyone has their favorites and I have mine, but Champions are very poorly made. They shear the electrodes during manufacture and do not grind them flat. So the gap is not even across the entire electrode, much like starting with wear from the day you put them in. I have not seen this in any other plug made. Even with their poor manufacture I'm sure Champions and any other standard plug you install will work just fine.

HTH,
B-loose

Last edited by Bloose; February 17th, 2004 at 23:32.
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  #5  
Old February 17th, 2004, 23:58
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Rawbrown Rawbrown is offline
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I am preferential to NGK's. They do have a "V-Power" plug that has shown no problems in the many years I have been running them.

has anyone had the autoshop class where the teacher runs that small single cylinder engine with the pyrex cylinder? you actually get to see the combustion process live. and sometimes the "path of least resistance" is not always a straight line, in which case the spark can arc around more like lightning.

now for the MSD... I swear by mine. if I had a dyno to put it on I would. and the only other mods I have done are a K&N filter and a TB spacer. everything else is stock. gas milage increased, quicker starting, smother idle, more power, flatter torque curve. anyone is welcome to come drive my jeep and feel the difference...
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  #6  
Old February 18th, 2004, 00:07
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Moto Moto is offline
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Yeah I have to say, I am a fan of the NGK plugs, they make some quality stuff, although it seems as though they have cheapened out recently while switching from the standard gold color, to silver in appearance, and so far they dont seem to hold up as well as the old ones. They seem to corrode alot quicker on the outside, but still work well. I agree stay away from the split fires, everyone that I know that has used them says they are crap, I have yet to hear anything good about them. As for bosch Platinums, I am running them right now in my Jeep, they work fine, but I remember that there was talk on here a while back about the possibility of them coming apart and having pieces fall off into your engine, I have yet to see this happen, but have been told that it could so take that for whatever it may be worth.
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  #7  
Old February 18th, 2004, 01:22
RobertF RobertF is offline
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ND U-gap plugs, been using them for 25+ years in racing motorcycles and nothing comes close for the price.(Wonder where Splitfire got their "idea" ten years later?) Accell sells them with yellow insulators re-labeled as theirs for high performance use.
All the parts stores push the most expensive plugs they can for their profit, not your performance.
ND's Q20PR-U are standard for the non-HO 4.0 at $2.25 ea.
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  #8  
Old February 21st, 2004, 04:30
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MudDawg MudDawg is offline
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Having worked with engines for over 30 years...I can recommend most highly the NGK plugs...the Bosch plugs are ok...and if you want to "buy american" autolite/motorcraft are good also...in my experience, the multi-electrode plugs are no more effective than conventional plugs and in some cases are inferior...On the exotic metal combinations...go for it...they wear much better.

Just dont forget the rest of the package. I have seen far more ignition problems caused by defective plug wires and distributor caps than any other reason....Finally, don't confuse "poor" plugs with fouling caused by internal engine/fuel system problems.
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  #9  
Old February 21st, 2004, 08:14
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Kejtar Kejtar is offline
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Quote:
Originally Posted by MudDawg
Having worked with engines for over 30 years...I can recommend most highly the NGK plugs...the Bosch plugs are ok...and if you want to "buy american" autolite/motorcraft are good also...in my experience, the multi-electrode plugs are no more effective than conventional plugs and in some cases are inferior...On the exotic metal combinations...go for it...they wear much better.

Just dont forget the rest of the package. I have seen far more ignition problems caused by defective plug wires and distributor caps than any other reason....Finally, don't confuse "poor" plugs with fouling caused by internal engine/fuel system problems.
OK, I got the...... (drumroll).... Champion truck plugs. I went to Kragen and he didn't have the NGK's that I'd use/need so as always being low on time, I got the "other choice".
In regards to the rest of components I picked up the HighPerformance wires and cap/rotor from the dealer I'm just about ready to go to the garage and swap all that in.
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  #10  
Old February 21st, 2004, 08:21
JnJ JnJ is offline
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Wow a real MOD Tech Post!
Quote:
Is there more then one type of a sparkplug that the dealer offers?
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  #11  
Old February 21st, 2004, 08:24
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NGK

Not platinum, not split electrode, just the plain vanilla, standard NGK that's listed in the book for the 4.0L

The rest of that stuff is snake oil.
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  #12  
Old February 21st, 2004, 09:56
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REDXJ4FUN REDXJ4FUN is offline
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I used the truck plugs my 89 454 chevy and those combined with a jacobs igntion an plain and simple did last. so good old ac plugs and MSD wires and a good coil all replaced the jacobs setup. I use nothin but the +4s in my 4.0 motors that combined with good wires has real impressed me.
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  #13  
Old February 21st, 2004, 10:53
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8Mud 8Mud is offline
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Think there may be factors, other than the plug brand. I had a set of Bosch I used to replace a set of Bosch already in the vehicle. Miss was still there, changed all the wires and cap. Still had a miss. Pulled a set of old factory wires off the shelf, replaced just the coil wire, miss got better, changed to Champ plugs, miss disappeared, along with a mid range stumble in acceleration.
Didnīt do a serious investigation, but did notice the difference in resistance in the Bosch plugs (really high), AC plugs (had a set on the shelf) and Champions. Also noticed a difference in the coil wire, between stock and the parts store special I replaced it with.
May be the computer, works better with a near stock resistance. At least on the Renix, maybe the OBD I or II is more adapatable.
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  #14  
Old February 21st, 2004, 11:10
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Lucas Lucas is offline
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I suse Bosch single platinums only becasuse the electrode wears longer, and well, im lazy.I think they work great. I put them in my Mom's jeep and after 50K they look like new. I had a set of normal champions in my jeep before I replaced them with the platunuims, and the copper electrodes looked very worn down.
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  #15  
Old February 21st, 2004, 11:54
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RichP RichP is offline
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I only use the dealer supplied champions, reason being is that I bought some from advance auto here, just happpend to have an extra OEM plug with me and I compared that OEM plug to the SAME MODEL champion at AA, the plug was different. The OEM one had a thicker ceramic center, thicker electrode and thicker tip. The difference was visible to the naked eye. My OEM plugs, wires, cap and rotor got changed every spring and that used to be 60,000mi when I was commuting to NJ. I also noticed that the OEM ones are gapped to the correct space while the AA ones had to be done. Nope, I'm happy with OEM and the $.50 a plug price difference is no big deal seeing as how when the time comes around I just make one stop for the plugs, wires, cap and rotor and I KNOW it's going to fit, work and hand me no suprises.
I went thru the NGK, Bosch plug game with my Trooper and none of the fancy plugs worked any better than the stock plugs I got it with. The manufacturers spend a alot of time and money getting the best MPG, emissions and reliability when they test for acceptance and certification. If there was a miracle plug out there I think they would use it but they generally build for reliability and good performance so I'm not going to reinvent the wheel.
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