Jeep Strokers

OK, I've not seen a lot of references to running Spark Plugs implying that the stock plugs are proper/adequate.

In my build I'm also going to use a D.U.I. Live Wires and Sreamin's Demon Coil. I selected the E3 Spark Plugs to hopefully take advantage of the fullest most complete spark. Now I know some hate them and some love them, just as with all aftermarket products/brands.

So in an attempt to be sure I properly gap them to take advantage of the D.U.I. setup I contacted E3 with the following question:

I'm rebuilding my 1993 Jeep YJ 4.0L, and am stroking it to 4.6L. I'm also installing a D.U.I Screamin' Demon Coil, Cap, Rotor and Live Wires. I've also purchased a set of E3's E3.58 Spark Plugs.
What concerns, gap recommendations, etc do you have? D.U.I states to open the gap up to .065". I've heard good and bad on the E3's (just as you do with any product), but want to make sure I get this right. I plan on running the old plug for the cam break-in, and then do the oil/filter change and swap in the E3's at that time. Looking for your comments/directions/warnings, etc...

Here is the response from ES:

Thank you for your interest in E3 Spark Plugs. We do not recommend starting the engine of a new build for the first time with our plugs. Our ground wire has far more material than a standard J-wire and without knowing what heat range your engine requires if our plugs were too hot it could be detrimental to the build. By bringing together all of the various components of your custom build there is no way of knowing the heat range required by the engine without performing trial and error runs. After running the engine and finding the right heat range your engine requires, I would be happy to see if there is an E3 replacement suitable for your engine's needs.
First test out standard J-wire copper plugs to determine the correct heat range your engine needs. Than based on that part number I can determine if the E3.58 is a suitable replacement. The E3.58 that you found is for a 4.0L stock Jeep engine, not a 4.6L modified stroker.

So what experience/recommendations/concerns do any of you have?

If any of you are running the Screamin' Demon Coil and Live Wires, what plug gap are you running?

Will

One heat range cooler spark plug, stock gap. "Upgraded" coils are more of a marketing gimmick than anything.

Thanks, by stock coil had several cracks, and since I wanted better wires, I just went with the complete kit.

So which plug would you recommend?

I gave E3 the stock and only other plug I'd seen referenced here and gave them this:

The stock plug would be a RC12LYC, the only other plug I've heard anyone running in a stoker was a RC9YC4.

Their response was:

That is a significant difference in heat range. I suggest running the colder RC9YC4 first and determine if this is too cold a plug or not. It is always best to start colder rather than hotter.

Will

Their advice is sound. I ran the RC9s for the first 30k and now I'm on NGK BKR6E(great for my 95M3 too!).

i am using the ngk bkre6 gapped at 035..works good on my 150 shot.i used the live wires years ago (2005) and had a problem with spark plus boot terminals breaking off no matter how careful i was..other that that good wire till the first spark plug change.i am using the msd wire again and i like those.

NGK recommend to use the ZFR6FIX-11, stock # 6441 for an Iridium plug or ZFR6F-11, stock #4291 for the V-Power copper plug.

I'm running the ZFR6F-11

Thanks, I'm going to ship the E3's back.. D.U.I. got back with me they recommend the Autolite Platinum plugs as they are very good about maintaining the wider plug gaps they recommend.

Will

W_A_Watson_II wrote:The stock plug would be a RC12LYC

He he, those are the plugs I'm using in my stroker, and that's in a country where the daytime temp. is 100+*F for at least 6 months of the year. They work great for me but in your case, it'll be a good idea to start with colder plugs and see how well they work. Platinum tipped plugs will last longer but they don't perform any better than the stockers, so it's up to you if you want to pay more than double the price of Champions for a set of platinum plugs. I've been there done that and in all honesty, it's hard for me to recommend anything other than Champions.

Thanks.

Guess I'll try one of these, just not sure how cold to go:
Champion Nickel Spark Plug #RC9YC4
Champion Nickel Spark Plug #RC10YC4

Will

OK, a question. I started the engine for the first time today, and about half way through the cam break in it developed a miss. See the following videos:

https://www.youtube.com/watch?v=9JlxJS7 ... ature=plcp
https://www.youtube.com/watch?v=chEJR8H ... ature=plcp

I started with my stock plugs for the break-in and was going to swap in the cooler (RC9YC4) plugs with the initial oil change. Is the miss above likely caused by the higher heat range plug? I let the engine cool down some and re-started it and the miss wasn't there, but I suspect it would have returned if I let it run long enough.

Thanks for any and all help,
Will

Its a possibility. But doubtful. I would start diagnosing it like any other misfire.

Well after yesterdays engine start and cam break-in, it was time to change the oil and install the new Spark Plugs. I elected to do the break-in with the old plugs figuring there might me some oil or other burn off that I didn't want to harm the new plugs. Not sure it was a wise idea, but I did it. As you can see in the first picture, Cylinders 3 & 4 (and partially #6) either weren't cleaned enough, or have problems and likely caused the miss the engine developed during the break-in. In the second picture you can see the cooler heat range NGK BKR6E-11 (RC9YC4) Spark plug next to one of the old Champion 4412's. (RC12LYC).




http://www.jeepforum.com/forum/f12/star ... st14094522
http://jeep.wawii.com/93YJ_TrannyJob.htm

Will

How did you come up with that plug number? Looks like a non-projection tip style.

SilverXJ wrote:How did you come up with that plug number? Looks like a non-projection tip style.

I was wondering why the difference, was the champion 4412 the wrong plug, or is the cross reference wrong?

Gave the champion number, RC9YC4, to the Parts guy. As best as i can tell it crosses to the NGK correctly.

Also it looks like Gradon is running the NGK BKR6E as well.

From what I recall wont a projected tip (longer deeper into the chamber) pull more heat from the cylinder? The colder plug will just have a shorter/less exposed insulator so its temp remains lower correct?