NA spark plug questions

[akhilleus]

he means instead of having the electrode arm interefere with the entering charge, with the plug "open" towards the intake valves it would allow for better/quicker combustion. However i dont understand how the injector could spray the plug when the AF is mixed in the IM.

 

[Installshield 2]

However i dont understand how the injector could spray the plug when the AF is mixed in the IM.

Come again?...You mean on the mustang, or on our cars???

 

[p5sundevil]

our cars i would assume, ill be getting new plugs soon so this is a good thread, i need to fully read through NGK's tech section to make my choice, though I will tend to go with the extended reach that most are going with, normal heat range since i wont be raising compression or rev range any time soon.

 

[Gen1GT]

Don't forget that you'll lose some static compression by having less plug inside the combustion chamber.

If you want real results in your combustion chamber, do a 3 or 5 angle valve job and unshroud your valves. Like I said, it's easy to get gains in a Mustang, which already has a poorly designed head. But these are relatively well designed pieces, with not a whole lot of room for improvement. If this technique worked, and is pretty easy to do, why isn't it done from the factory?

I'd still love to see a dyno of this mod, to see how the anecdote turns out....

 

[akhilleus]

I will probably do a dry run at some point...to see how easy it is to position the spark plug....then if it seems worth it i will do it during a dyno. I still think that i should change back to the 5 heat range. I highly doubt i have increased my comp. enough to warrant the colder plug.

edit: i found this to be informative
http://www.fordmuscle.com/archives/2000/07/indexplugs/index.shtml
although the fs and bp combustion chambers are much better designed... so that the electrode is never directed at the chamber wall, it would still be helpful to have the gap open towards the intake valves and it also aligned so that it doesnt block the exhaust valves. if mustangs show a 4whp gain...i would expect less than 2hp.

 

[twilightprotege]

dont forget akhilleus - you're better off going for a slightly colder plug than a hotter plug. i have run on denso ik20's since new and i'm about to change to ngk's iridium plugs in the 6 heat range

i might try indexing when i get my new plugs shortly too. like you say, it cant hurt...but then again i dont have extended reach plugs. any thoughts on this???

 

[Gen1GT]

It's hard to say if this is speculation, or actually works. A 4.9L engine has quite a bit more displacement, and they're only getting .5hp per cylinder. It could have been because it has fresh plugs, not because they were indexed. I think if you had extended reach plugs, it raises your compression ratio, and will probably give you more power because of it. All of this could show up as a couple hp on the dyno, but then again, a dyno run can vary up to two hp per run because of changed conditions.

I'm trying to picture how it would all occur in the combustion chamber: the valves opening, and they cylinder filling, and I think the plug electrode is so small, and it's in between and away from the valves, that I can't picture it interfering with the airflow. Oh well. Try it anyway, and let us know how it goes....

To do this accurately, you're going to have to dyno your car as is, dyno it with fresh plugs, then dyno it with indexed plugs. You wouldn't want to be mislead by fresh plugs appearing to give you the power indexing was supposed to....

 

[akhilleus]

i am going to the track on weds.. I am going to hold off on anything until afterwards..

 

[Ghost Buster]

a 4.9L mustang?? Not mine, surely you're not speculating as to what I drive. My mustang is a 92 2.3L automatic.

a gain is a gain, do it or don't, I don't care. I'm not on this board to be criticized. I was just offering some advice that's been proven to work other vehicles and my own personal vehicles.

 

[Installshield 2]

Don't take constructive criticism personally...Josh is not attacking you, he is just trying to give light to assumptions and speculation...which is the whole point of these boards...Most people look for information on potential mods...Being that this is a very easy thing to do, and has been proven to help on a number of other cars; making a situation where the only thing to loose a little bit of time...Notice that this is in the "NA Tech" section, and Josh is giving "technical" descriptions of what this mod is even related to...

Your advice is appreciated...but there were always be people to break down and scrutinize what is being said...which prevents BS ten fold...Josh is simply pointing out that there are a number of other variables that could have contributed to your 4whp gain than just the indexing...

Anyway...Aky, what I was pointing out was that the swirling and mixing of gasoline and air takes place mostly inside the combustion chamber...Not in the intake manifold...some residual fuel will reside in the intake ports within the head, and mix a little before entering the chambers...But the EFI system will spray the gasoline "aerosoled" (sp?) during the valve opening sequence...and during the intake stroke fresh air is pulled in as well, which mixes the two before the compression stroke begins...

Pretty sure that is redundant...but wasn't sure what you were referring to...

 

[Gen1GT]

a 4.9L mustang?? Not mine, surely you're not speculating as to what I drive. My mustang is a 92 2.3L automatic.

a gain is a gain, do it or don't, I don't care. I'm not on this board to be criticized. I was just offering some advice that's been proven to work other vehicles and my own personal vehicles.

Would that happen to be a turbo? Even still, there are tonnes of power to be made from the 2.3, but I'm not sure it's combustion chamber design is much better than the Mustang's 4.9....once again, two valves per cylinder makes a difference.

Also, I wasn't criticizing you, I was criticizing plug indexing. It just so happens that it was your recommendation, but don't take it personally. As everyone on the board knows, I'm critical and sceptical. I believe that extraordinary claims need extraordinary evidence, and I don't take anything for granted. It's nothing personal man.....

 

[Ghost Buster]

you consider 4whp EXTRORDINARY?? wow, I'm not going to enjoy owning a protege then.

 

[Gen1GT]

Show me where I said 4hp was extraordinary?

Plug indexing on a Protege is extraordinary, whether it's .5 hp or 150hp. I'm not say, "this may not show very much of a gain", I'm saying, "this won't show ANY gain." If it works, I'm going to need to see extraordinary proof, like a dyno chart.

Are you going to recommend we run 25 degrees ignition advance, run ring end gaps of 20 thou and hog out our intake ports too?

 

[Replica]

Blah, so i need to replace my factory plugs, what am i going to buy? They make NGK's for Slowteges?

 

[Gen1GT]

They're the only ones you should use IMO.....

 

[akhilleus]

yes get the Vpower extended reach ...i think its bz5 soemthing as the part number. Although the p5 and es come with the ngk vpower.
Otherwise id ont think the rest of this conversation is even relevant, Postioning the plugs so that they are at the optimal area to ignite the mixture is going to help no matter what, 2 valves or 4. Although the gains might be minimal, josh...you yourself have shown some very minimal gains from some mods that some could argue are not worth it...indexing the plugs is a simple and conceivably beneficial mod...if it got me 1hp i would be happy. It does seem though josh that your are very set in your ways....If someone criticized your idea of putting carbs on your car i could see you responding negatively. I think that you dont need to constantly criticize, whether constructive or not, once is enough. A member has already said that he has shown gains from a mod..on a 2.3l...which was probably 16valve anyway. So lets try it and see...if it doesnt work u arent out any money or time...maybe u should try it also josh.

 

[Replica]

What is extended reach? Is that a factory replacement? Does the extended reach just make the plug farther into the combustion chamber? I've been getting a little hesitation around 6,000 rpm, thought it might be "new spark plug" time...

 

[akhilleus]

yes extd. reach means the electrode sticks out farther. it will fit....no problem. if u want ..u can get platinum which last alot longer and also u can get colder heat ranges but only if u plan on doing serious work.

 

[Replica]

I used NGK's that were 2 heat ranges colder on my old boosted civic and they were great, this "extended reach" stuff is new to me. For a simple "bolt ons" p5 a hotter plug would be best right?

 

[akhilleus]

that is debatable. On something where u will be changing the comp ratio, such as cams, headwork, and HC pistons a one step colder plug would help. I am using one right now, but i have yet to deduce whether it is worth it or not...it didnt hurt as far as i can tell but i will probably buy a set of extd reach 5heat range and compare.