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Adler, I have a small tech question. My Jeep has the 5.2 litre V8. I am wondering if they offer a cooler spark plug in the European countries than they offer in the States. They only offer one Temperature range here. The reason I ask, I've made a few upgrades to the ignition system and the plugs are turning a brick red which indicates they are getting to hot. The fuel mileage is a lot better but I'd like to get the temp down just a hare so I don't burn a valve or piston. Thank you in advance.:thumbright:
 
Aaron, can't you just drop one in the range?

Also, North American engines tune a little different than Euro engines because of the Federal emission standards.

You should be able to go to your parts store (a real parts place, not a Kragen's or Checker) and have the parts guy find the heat range in the back of the book. Typically, the lower the number, the cooler the plug.

The other thing to look at, is perhaps the engine is running a bit too lean...
 
Dave, I've checked with all the plug makers and they only offer one temp range for that motor regardless of what it is in. I just figured it might be different across the pond.It's kinda frustrating.
 
I hear ya'...after I posted my reply up there, I looked to see what the 5.2 requires in my books, and there's not much in the way of options for your engine.

Something did occur to me though, you mentioned the plugs had reddish deposits on it. That's not overheating, that's fuel additive deposits. If your air/fuel mixture was too lean, causing an overheating problem (and/or too high of a heat range), your plug would have some different indicators than you mentioned.

Overheated plugs would have kind of chalky looking insulators, pitted electrodes and a dark blue (real dark, might even look black) shell. I have even seen blistered and partially melted electrodes, with what looks like metallic splatter on the insulator. This can be caused by bad timing, bad EGR, a vacuum leak and like I mentioned above, bad air/fuel mixture or too high of a heat range on the plugs (or a combo of one or more of these).

Whatever you're putting in your fuel is the culprit there, mister...otherwise, I think you're ok...if you have a good engine tech back there in your neck of the woods, talk to 'em about what I've mentioned and see if they agree. :)
 
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Aaron Brooks Wolters said:
Adler, I have a small tech question. My Jeep has the 5.2 litre V8. I am wondering if they offer a cooler spark plug in the European countries than they offer in the States. They only offer one Temperature range here. The reason I ask, I've made a few upgrades to the ignition system and the plugs are turning a brick red which indicates they are getting to hot. The fuel mileage is a lot better but I'd like to get the temp down just a hare so I don't burn a valve or piston. Thank you in advance.:thumbright:
Click to expand...

I can check, but I am not sure. In my old 95 Jeep, I also had the 5.2 V8.
 
GrauGeist said:
I hear ya'...after I posted my reply up there, I looked to see what the 5.2 requires in my books, and there's not much in the way of options for your engine.

Something did occur to me though, you mentioned the plugs had reddish deposits on it. That's not overheating, that's fuel additive deposits. If your air/fuel mixture was too lean, causing an overheating problem (and/or too high of a heat range), your plug would have some different indicators than you mentioned.

Overheated plugs would have kind of chalky looking insulators, pitted electrodes and a dark blue (real dark, might even look black) shell. I have even seen blistered and partially melted electrodes, with what looks like metallic splatter on the insulator. This can be caused by bad timing, bad EGR, a vacuum leak and like I mentioned above, bad air/fuel mixture or too high of a heat range on the plugs (or a combo of one or more of these).

Whatever you're putting in your fuel is the culprit there, mister...otherwise, I think you're ok...if you have a good engine tech back there in your neck of the woods, talk to 'em about what I've mentioned and see if they agree. :)
Click to expand...

DerAdlerIstGelandet said:
I can check, but I am not sure. In my old 95 Jeep, I also had the 5.2 V8.
Click to expand...

Thanks guys.:thumbright: The biuldup is not heavy. It looks just like dark brick dust. I have installed a MSD box and MSD factory style coil. Upon doing this I kept bumping the gap up from .035 to .050 in .005 increments until I just barely heard spark knock and am now running it at .045 gap. Again, thank you cause I'm just hunting and pecking for more power and MILEAGE.:lol: :lol:
 
Nice car Aussie! Earlier on in the week I became the the proud new owner of a 1995 Ford EFII XR6 Falcon. Will take pics when the weather clears up.
 
Aaron Brooks Wolters said:
My Jeep has the 5.2 litre V8. I am wondering if they offer a cooler spark plug in the European countries than they offer in the States. They only offer one temperature range here. The reason I ask, I've made a few upgrades to the ignition system and the plugs are turning a brick red which indicates they are getting too hot
Click to expand...
Plugs don't make a heap of difference to how hot the engine runs, it's how hot the engine runs that determines the design of the plug. GG may be on it with the 'leaning out' theory, possibly an open-circuit TPS or a MAF starting to deteriorate.

Re your upgrade, if your Jeep has an engine management system, how much of a positive effect is the ignition system upgrade really having? Ignition system upgrades work well with non-managed engines but I would have thought the ECU was already making the best possible job of the combustion.
 
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Colin1 said:
Plugs don't make a heap of difference to how hot the engine runs, it's how hot the engine runs that determines the design of the plug. GG may be on it with the 'leaning out' theory, possibly an open-circuit TPS or a MAF starting to deteriorate.

Re your upgrade, if your Jeep has an engine management system, how much of a positive effect is the ignition system upgrade really having? Ignition system upgrades work well with non-managed engines but I would have thought the ECU was already making the best possible job of the combustion.
Click to expand...

Colin, it does have an management system. Upon installing the upgrades, the coil first and opening the spark plug gap to .050 the Jeep ran a lot better and the fuel mileage went up almost 3 miles to the gallon but I was getting a lot of detonation in warm humid weather so I purchased the MSD Street Fire CDI box. It multifires up to 11 times per cylinder up to 3,000 rpms and then goes to single fire phase above that rpm. Installing the box eliminated the detonation and made the fuel mileage average out better. Now, as far as plug temperature. A hotter plug can cause premature detonation. If you run a cooler plug with the ignition that I have installed you can up the gap on the plug to a degree without causing premature detonation because your base temperature started lower. Now, going with a larger gap causes a larger flame field giving the fuel more flame surface to ignite upon and seeing as how the spark is cooler your cylinder temp stays cooler in turn upping you fuel mileage, hopefully. I learned a lot of this watching drag racers. If they had a detonation problem that they couldn't solve with the gap they would drop a heat range or two with another set of spark plugs and set the gap accordingly. Oh, and I almost forgot. The ECM does not use the spark plug as a sensor like the MSD box does so therefore the control module has no idea what's going on in the combustion chamber and these motors don't have a knock sensor either so the MSD box does a lot better job than the factory ECM by itself. The MSD box uses the plug as a temperature sensor to let it know how many times to fire the plug from one to eleven times per cycle. Hope this helps. I may be barking up this tree for nothing for the ECM may read this info that I install and compensate in the other direction. I don't know but I still want to try.:) :)
 
Aww SE, that's exactly the car i wanted :p I like them in white with the red pinstripes....Sooo nice.
Im looking to save up for a BA XR6 though, love the lines of them...They look really neat.
 
Just my VS Holden. Duel fuel, LPG and petrol. I can drive 10 hours straight at 110kmph without stopping. Did it from Coonabarabran to Broken Hill.
 

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