spark plugs

[fireboss]

O.K. guys I have an 84 normal asperated 8 valve. I have installed a Pro Street Jacobs Electronic System (control pack,coil,wires). I also have installed a set of headers and run 2 2/1 inch exhaust and taken the cat off. I'm running the O.E.M. air box with a K&N (took off the small inlet pipe to open it up more). I am using 100 Octain unleaded. Can anyone reccomend a Spark plug tfor tis set up? Or does anyone have an opinion as to where I should set the timing?

[Lawrence Coppari]

I bought the same thing for my 951. It worked for only 10 minutes before engine began missing. Never could get it straightened out. I sent it back for a full refund. For the brief time it ran I noticed a difference or so I thought.

Their technical people do not recommend platnium plugs or splitfires or any of that other stuff. Just use ordinary plugs and open gap according to their chart.

The plug wires sent with the system left much to be desired. They did not cover the hole in the cylinder head as do the OEM wires. They also did not firmly attach to the plugs.

Please keep us posted what you experience with the system.

[dmac]

The 100 octane does nothing but empty your wallet. 87 is recommended.

[Scott R]

I use the Bosch supers on Supercharged N/A. I also am looking for a perfect timing setting, but I am looking at the MSD in car timing control system. Sounds like you may need one as well.

[EGSMachine]

Try these. i just bought a set.


http://www.densoiridium.com/findmypart.asp

[AMCPorsche924Powerhaus!]

i saw some bosh AG plugs in the store, they are expensive.

AG means silver of course...

I heard silver is the best conductor out there in sparks these days..has anyone used them...eurospec i know you have those nology silver ones..so what about these boshc silver ones..

In my opinion I think all the spark plugs out there are a hoax, except the ones that use different materal but keep a good size..for example those platiums, are hoaxes, they have such a small point that imo they are not worth it, and i heard they have resistors in them...and those four prong ones, a hoax. you do not need four prongs, you need one, the spark does not miss the one prong some times, it always hit sit, it does not need four prongs just incase it misses the one prong, because it won't f*cking miss it, and that is that!

THe v-grooves: hoax.
carbon fills up in the grooves, its a nuisance to clean the things, there is more surface for carbon to fill up in a clog up, absolutely useless.
A groove does nothing for elecricity! Put a groove in a wire, and it will cause the wire to burn up easier, and fry! Hoax!
You want a nice even path of electricty, not one with a f*cking groove in it!

Platinum ones, i forgot to mention...harder to clean and to tell if they are dirty with such a small point on them...nuisance...normal plugs are better.

NOW, what i do agree with, is spark plugs that are just like normal plugs, but are different materials..ie/ nology silver plugs...i haven't tried them....but they make sense to me...

[AMCPorsche924Powerhaus!]

A couple other notes...

The four prong ones cover up the spark more, the spark is hidden by four prongs rather than just one...

In addition to types of spark plugs to use...there is also some tricks you can do...the depth of your spark plug, and the direction your prong is facing.

If you find a perfect depth for the spark plug to go into the head (they make long and short plugs, and u can use washers), you will get better results, because there is an area in your combustion chamber that probably has a better response you the spark.
Second thing, the direction of your prong thing...try it at diferant angles, the little prong that the spark grounds out to...there is probably a best position for it to be in, use a washer to change it.

That might cause conflict though, u are using a washer to change the angle and to change the height...so u will have to have a ton of washers on hand to get the perfect set up, thick ones thin ones, and u probably would need a dynometer or something in order to find out the best position, u rn't gonna notice it just by driving your car and testing.

[TheStig]

I use Beru Silverstone sparks in my 944 with 91 octane gas. 87 causes my car to ping.

I saw something on the internet that tells how each metal is conductive from least (bottom) to greatest (top)

-Gold
-Uranium
-Tungsten
-Silver
-Copper
-Steel alloy
-Vanadium
-Platinum <----NOTE
-Chromium

This is only some of the metals on the list. But enough to show significance.

BTW: Jacobs sucks....I felt no improvement until I switched to NOLOGY.



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Porsche. Es gibt keinen Ersatz.

[EGSMachine]

i think your source is bad. gold has a conductivity of 70% of copper. silver is 106% OF COPPER. tungsten is 31% of copper, platinum is a whopping 17%. Iridium is a stagering 32%. the benefits are wear resistance, and maintanence of the point, i.e., spark control

[This message has been edited by EGSMachine (edited 08-11-2001).]

[This message has been edited by EGSMachine (edited 08-11-2001).]

[MAS]

No, gold has the greatest conductivity... definitely more than copper. The main problem is the expense. Silver has greater conductivity than copper too. Copper is more widely used simply because it is cheaper.

-MAS

[IceShark]

Wrong, gold is #3 on the scale at 65, not much above aluminum. Silver #1 at 106, copper #2 at 100. The main benefit of gold as a conductor is resistance to corrosion, otherwise you would probably never see it used much as a conductor.

[AMCPorsche924Powerhaus!]

Maybe the reason you guys are getting mixed up is because you are mixing up ions and actual metals, there is a difference you know, for examply licking and eating your car will not give you extra iron minerals.

[TheStig]

he's right. Gold is the highest in conduction but it cannot withstand combustion temperatures and it would surely melt the electrode. Silver on the other hand has a higher melting point than gold, giving it a longer durability and plug life. Coming from someone who has ran everything from bosch platinums to NGK high conductivity racing copper plugs, I still choose Beru Silverstone over the rest...there's just no comparison. All of your fuel gets COMPLETELY burned in the cylinders. Talk to some of the 911 guys, they use silver or racing copper plugs in their 930s turbos and even in their twin turbos.



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Porsche. Es gibt keinen Ersatz.

[AMCPorsche924Powerhaus!]

http://www.amm.com/ref/conduct.HTM

GOld is not the highest conductor, are you talking about heat conduction? an ionic compund with gold ions in it?

It all depends on the temperature, I want to see some charts with engine operating temps...and the ratings at the engine operating temp.

[fireboss]

Thanks for all your help guys. I use the car stickly for autocrss. I went with the Autolite 64 copper core plug and set the cap at .055. The car is running GREAT. I have an event tonight and will share with you my results. I have not been able to index the plugs and have the indexing washers on oder. Having never pulled the head I do not know which way to point the electrode to get maximum burn. Any help in this area would help. Otherwise I will have do do it by pulling and reading plugs after every run and thats a pain.
Thank again.

[AMCPorsche924Powerhaus!]

just some info about metals easily available from a periodic table of elements, but not conductivity, the other source is the link i posted above:

-gold is very soft, not good. not a good conductor compared to silver anyways at 20 degrees celsius

-platinum is very dense and has a very high melting point, not as good conductoer as silver at 20 degrees celsius (80 ferenheight)


-silver has alower melting point than platinum, gold, copper. the melting point is 962 degreees celsius. YOur car never gets to those temperatures, but it is an indication that silver may wear down easier and faster? im not sure...

Now we need some charts to see how these metals operate at engine temperatures, not 20 degrees celsius...SO far silver looks the best for plugs, but this is at 20 degrees celsius and silver has the lower melting point...who knows if that means they last a lot less timewise.


About aiming spark plugs, maybe if you used a dyno or something it owuld be faster, I don't think you will notice that much of a difference to tell just autoxing the car...it's to hard to rule out other factors such as change of weather or heat of tires.

[Ehab]

Even if silver is a better conductor than gold, and has a higher melting point, there is another factor to take into consideration: REACTIVITY ... Gold is better than silver because it does not react and Oxidize as easily ... Platinum is even better because it is very stable ... that is why silver jewelery tarnishes much easier than gold and platinum ... and hence gets coated with a layer of oxide that insulates it and makes it harder to spark ...

The silver plugs might conduct more electricity for the short time they are CLEAN, but IMO, they have to be maintained much more than platinums ... that's why I have platinums.

About the 4 prongs, they do NOT cover the spark more than the single prong, if you look at the design, you see that the prong are shorter and don't go over the top, but rather stay to the side, and hence they produce as good of a spark ... the fact that there are 4 instead of 1 just means that the spark has 4 options of the route to take ... and hence uses the one with the least resistance, whichever one that happens to be at that point in time.

If you firmly believe that 1 pronged plugs never miss, then you might think that the 4 prong is useless, but the fact that you can take a lower resistance path means that you can produce the spark faster (lower threshold voltage for air to break down and conduct the spark) and hence your DME will be happier in adjusting its timing according to the load on the engine.

I use Bosch +4 plugs now, and I certainly noticed smoother idling/operation than with the normal Bosch plugs ... platinum just means durability to me ...

Ehab
S.B. Engineering, Harvard University
Ph.D. Candidate, Engineering, MIT
Not kidding ...

[AMCPorsche924Powerhaus!]

Pure gold would be way too soft. I already pointed out that platinum stands out in the durability area. Just like endurance runners won't do jack in a sprint...they suck performance wise if performance is defined as speed in the situation.

Copper is more prone to reactions with water than silver is. Silver will not react to water like copper will when you turn your car off and the moisture attacks it.
I would still take the copper over the platinum, pulling the plugs on the car IMO comes natural and is really easy and fun, and a good way to monitor your engine, so no harm done. Platinums are gonna make me say "nah to heak with maintaining my car", same with synthetic oils.

http://www.schoolsnet.com/cgi-bin/inetcgi/schoolsnet/classroom/sci116.jsp

As you can see here, it's not that big of a deal, all four are at the bottom of the list in reactivity of some common metals, there isn't two there that are at the top of the list that i am suggesting you use.
It is not as if silver is one of the alkali metals! All their electronegativities are around 2.0, platinum is the highest at 2.2 and is a very poor conductor compared to copper and silver. And the small diameter final point jargon that the platinum has, so that it "concentrates" the spark, is just another marketing tactic (or dumb scientists), because you are dealing with very high amounts of electricity, and with high amounts of electricity, the electricity is at a greater charge on the surface (the walls of the silver or platinum or copper, whatever material it is)...you still need the center part of it to carry the electricity through to it's maximum efficiency, but the greatest charge occurs on the outside...more material, better, IF you have a powerful ignition.
A weak 1950s ignition response very well to platinum plus fours with v-grooves in them, easier faster path to travel.
Anything EASIER to travel using a constant material, requires less amperage to travel through it in order to make it happen, meaning your spark will have to be weaker.

If we want' a durable spark plug I say screw platinum, let's use fluorine cores, with a startling electronegativity of 4.0.

[AMCPorsche924Powerhaus!]

http://hkcee.oe21.com/En/Subjects/HKCEE_3/2-2.asp

and look at that, since silver is also an exceptional heat conductor...it doesn't foul as easy from it's own self...no apparant reaction occurs under high heat in air, very special in an engine.

[This message has been edited by AMCPorsche924Powerhaus! (edited 08-11-2001).]

[jseel]

i have used bosch copper then platinum then indexed silvercores then +4's(in my '83). the silvercores and the +4s are by far the best. if you take a 944 head thats not on the motor run a plug in it, the +4 does not block any spark or need to be indexed like a conventional plug. thats why i went to them for my 951. they work great so far.the iridium plugs actually can do more harm than good in a stock ignition from what ive heard, but with all the extra spark they may be a good choice.