Fiesta ST Spark plug tech

[Sekred]

I think NGK LTR7IX is the wrong plug for own Ecoboost engine fellas. I brought a set and noticed a difference in the centre electrode design.
I ran the plugs anyway but I notice it was a little harder to start from cold and run on 3 cylinders sometimes for a few seconds.

The OEM plug have a projected centre electrode, these do not. Link to NGK, http://www.ngk.com.au/spark-plugs/technical-information/projection

Image I took so you can see what I mean. OEM plug on the left.

 

[Sourskittle]

I think the height it sticks out effects its heat range, hense why the ngk is lower than stock.

 

[razorlab]

Yes, non protruding vs protruding effects heat range, however the plug itself looks to not even be the same height in that photo. The base where the strap starts should be the same height.

Denso ITV22

 

[Sekred]

The OEM design protrudes further into the combustion chamber and I think for a reason. If you look at the piston design, it has a bowl shape in the crown usually called a Mexican Hat design, very common with current diesel engines. The crown acts like part of the combustion camber and the shape creates swirl to promote complete burning of the fuel/air mixture.

 

[JPGC]

Spark plug tech

I think NGK LTR7IX is the wrong plug for own Ecoboost engine fellas. I brought a set and noticed a difference in the centre electrode design.
I ran the plugs anyway but I notice it was a little harder to start from cold and run on 3 cylinders sometimes for a few seconds.

The OEM plug have a projected centre electrode, these do not. Link to NGK, http://www.ngk.com.au/spark-plugs/technical-information/projection

Image I took so you can see what I mean. OEM plug on the left.

View attachment 2688

Hmmm, I hope that we can find a for sure answer on this. I've logged mine before and after with both the NGKs and the stockers and to be honest, I can't see a difference. Now, with my car, it seems to idle better with the NGKs and I don't have the hard starting or 3 cyl. Issue that you are having other than the delayed start every now and again I get after swapping a tune. That happened with both plug types though. BTW, do we share the same plug factory as the Focus ST? If so, I think the NGK that we are using here is what they use as a step colder...I could be wrong though.

 

[JPGC]

Spark plug tech

Yes, non protruding vs protruding effects heat range, however the plug itself looks to not even be the same height in that photo. The base where the strap starts should be the same height.

Denso ITV22

Also, from what I know, our factory plugs are a fairly hot plug to begin with. The base would have to be shorter as you go colder with it. Especially if you went a step colder than this NGK (2step colder than stock).

 

[Hijinx]

JP, the colder plug we use is, in fact, the same one the FoST guys use.

 

[FORZDA 2]

Also, from what I know, our factory plugs are a fairly hot plug to begin with. The base would have to be shorter as you go colder with it. Especially if you went a step colder than this NGK (2step colder than stock).

The amount of the center electrode that extends past the threaded base has nothing to do with the heat range of the plug. It is referred to as "extended reach" and are used where needed to place the spark in the correct location for best combustion. The heat range is determined by how much of the base of the center electrode insulator contacts the inside of the metal base. The only way to eyeball the difference in a hotter or colder spark plug it to peer down into the space along the center electrode and see how much of it is exposed. Take some time and do a bit of research on these topics and all will become "smarter". The deeply dished pistons of the ecoboost engine requires the extended reach plug design for best combustion results. That doesn't mean a shorter plug won't run in the car, it means that it is recessed into the head area and hurts maximum power/performance. You will likely only see the results during precisely controlled dyno runs. However some have mentioned it misses or otherwise has anomalies with the shorter plug installed. That is an obvious indicator you have something "wrong".

I'm not trying to be an ass, (it just seems that way!) just throwing out some experience and facts for the less experienced folks.


Here is a short yootoob vid of some of my activities on another forum. http://www.youtube.com/watch?v=6lOlO67dC0M

 

[Hijinx]

Spark plug tech

I think I see where you're going... Considering that the threads appear to be equal, ignition is occurring higher in the cylinder, which could mean earlier which in turn could mean a loss of power... Does that also lend itself as to why a hot car wouldn't immediately start with the NGKs? Or am I way off base? BTW, our OEM plug is a Projected Metal Shell, not a Long Reach, or "extended." From that stand point we shouldn't use the Densos either.

 

[JPGC]

The amount of the center electrode that extends past the threaded base has nothing to do with the heat range of the plug. It is referred to as "extended reach" and are used where needed to place the spark in the correct location for best combustion. The heat range is determined by how much of the base of the center electrode insulator contacts the inside of the metal base. The only way to eyeball the difference in a hotter or colder spark plug it to peer down into the space along the center electrode and see how much of it is exposed. Take some time and do a bit of research on these topics and all will become "smarter". The deeply dished pistons of the ecoboost engine requires the extended reach plug design for best combustion results. That doesn't mean a shorter plug won't run in the car, it means that it is recessed into the head area and hurts maximum power/performance. You will likely only see the results during precisely controlled dyno runs. However some have mentioned it misses or otherwise has anomalies with the shorter plug installed. That is an obvious indicator you have something "wrong".

I'm not trying to be an ass, (it just seems that way!) just throwing out some experience and facts for the less experienced folks.


Here is a short yootoob vid of some of my activities on another forum. http://www.youtube.com/watch?v=6lOlO67dC0M

My Man, I'm not doubting your logic here...but not everyone is an expert at everything. The sharing of info on these forums would be useless if we all knew everything.
Now I see what you are saying here, but I guarantee that if you get the NGK equivalent to our stocker, the NGK 1 step colder, the NGK 2 step colder, etc (whatever the part numbers are)...the insulator will protrude less the colder you get...until the plug has to be shortened due to the insulator sitting too far in the base itself. I'm not the best at describing this in words, so here is an old AC spark plug description.

 

[JPGC]

Also, here is a link on YouTube where so guy did a comparison of denso plug heat ranges on a Focus ST. As he is showing the different plugs with different heat ranges, look at the difference in which the insulator protrudes.
http://youtu.be/oc0m7r7rQLo

 

[Hijinx]

Spark plug tech

I think what he's trying to say is we could possibly find a colder plug with the correct dimensions that put it in the same position. No...?

A long reach, colder plug would put the spark in a more appropriate place. If so, Denso ITV22 would be the call as Razor has said before. Or ITL20/22?

 

[JPGC]

I agree...that's why I said that I hope we can find a for sure answer on this I've seen the side by side with the stock plug versus the NGK, but not the stock vs the denso one step colder. I'm curious if it's as different as the NGK above.

 

[Hijinx]

Spark plug tech

See edit in my last post. I would totally measure my OEM plugs since they're out, but I'm not at home. One thing in convinced of is that the NGKs aren't the way to go.

 

[JPGC]

JP, the colder plug we use is, in fact, the same one the FoST guys use.

Panda motorwerks and Lethal Performace both sell the NGK LTR7IX-11 as the one step colder for the FoST. I would think it would be the same for the FiST...wouldn't it.

 

[Sekred]

A short description, projected spark plug.

"When selecting the spark plug “nose” configuration, the simple rule to remember is: The more the spark plug is exposed to the air/fuel mixture, the easier it is to initiate combustion. Many specialized plugs have been developed for high-end race cars, but for most dual-purpose vehicles the choice typically boils down to either regular-gap (conventional) or projected-nose styles.

The regular-gap plug is the traditional configuration factory-installed on many classic musclecars. For modern high-performance work, it should only be used if there isn’t enough clearance for a projected-nose plug. The latter style “projects” the spark further into the chamber than a standard plug, and will nearly always offer improved performance if there is sufficient valve and piston clearance, although many nitrous oxide users prefer to stay away from them because of excessive heat buildup in the tip that can cause detonation.

Projected plugs initiate the flame-front closer to the center of the combustion chamber, which has an effect similar to advancing the timing. This lets the total ignition advance be reduced, decreasing the chances of detonation while providing superior throttle response. A projected plug’s longer core nose provides a hotter plug at low speed to help prevent fouling. As engine speed increases, the incoming air/fuel mixture flows across the core nose tip, providing charge cooling that effectively reduces the heat range for increased top-end detonation resistance. Today many race cars also used projected-nose plugs, albeit in highly modified form from the “civilian” versions—the ground electrodes are often cut back to help improve the flame kernel and reduce the voltage amount needed to fire the plug".


http://www.hotrod.com/how-to/engine/spark-plugs-tips/

 

[Sourskittle]

The mazdaspeed3 also uses the same ngk plug as a colder plug. Se need go just email NGK as ask them. I'm willing to bet, they know a little about spark plugs, lol.

 

[JPGC]

The mazdaspeed3 also uses the same ngk plug as a colder plug. Se need go just email NGK as ask them. I'm willing to bet, they know a little about spark plugs, lol.

I would think so, lol. I'm gonna go to there site and email them right now

 

[Hijinx]

^^^ that explains why I suddenly have more room for timing with these new plugs.

 

[JPGC]

^^^ that explains why I suddenly have more room for timing with these new plugs.

The question is are we degrading performance though. I can't tell by the SOTP, lol and like I said, I haven't had the cold start issue. I did just email NGK though.