Ls9 Head Gaskets
06-03-2017, 03:54 PM
#41
excerp....
"Heat rating and heat flow path of NGK Spark Plugs
Some basic structural factors affecting the heat range of a spark plug are:
- Surface area and/or length of the insulator nose
- Thermal conductivity of the insulator, center electrode, etc.
- Structure of the center electrode such as a copper core, etc.
- Relative position of the insulator tip to the end of the shell (projection)
Based on this....for a given heat range plug, a BR7EF will be colder than a BR7EFS even though they're both technically a 7. Since the insulating tip is the hottest part of the plug, I don't want that projected into the cylinder if it's not necessary to do the job. That's just my opinion, everyone can do what they want. Some say they foul non projected 7s, but that hasn't been my experience.
06-03-2017, 04:18 PM
#42
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https://www.ngksparkplugs.com/about-ngk/tech-talk/spark-plug-basics
excerp....
"Heat rating and heat flow path of NGK Spark Plugs
Some basic structural factors affecting the heat range of a spark plug are:
Based on this....for a given heat range plug, a BR7EF will be colder than a BR7EFS even though they're both technically a 7. Since the insulating tip is the hottest part of the plug, I don't want that projected into the cylinder if it's not necessary to do the job. That's just my opinion, everyone can do what they want. Some say they foul non projected 7s, but that hasn't been my experience.
excerp....
"Heat rating and heat flow path of NGK Spark Plugs
Some basic structural factors affecting the heat range of a spark plug are:
- Surface area and/or length of the insulator nose
- Thermal conductivity of the insulator, center electrode, etc.
- Structure of the center electrode such as a copper core, etc.
- Relative position of the insulator tip to the end of the shell (projection)
Based on this....for a given heat range plug, a BR7EF will be colder than a BR7EFS even though they're both technically a 7. Since the insulating tip is the hottest part of the plug, I don't want that projected into the cylinder if it's not necessary to do the job. That's just my opinion, everyone can do what they want. Some say they foul non projected 7s, but that hasn't been my experience.
It doesn't exactly say, what you said it says. The part about extended/protruding tip plugs may be what you took it to mean, however that's not what it says or is intended to mean.
In the context, as it's written, there's no denotation about heat ranges being different for extended vs standard plugs.
It just explains how the plug absorbs and dissipates heat.
Again, I have no dog in this, my mind is open to all sides of the discussion, and I appreciate you and your posts.
Thank you for posting it in context. I appreciate it.
-Seth-
06-03-2017, 04:30 PM
#43
I did find and read that. Please don't take this as confrontational. I appreciate our interactions here and the mutual respect that exists.
It doesn't exactly say, what you said it says. The part about extended/protruding tip plugs may be what you took it to mean, however that's not what it says or is intended to mean.
In the context, as it's written, there's no denotation about heat ranges being different for extended vs standard plugs.
It just explains how the plug absorbs and dissipates heat.
Again, I have no dog in this, my mind is open to all sides of the discussion, and I appreciate you and your posts.
Thank you for posting it in context. I appreciate it.
-Seth-
It doesn't exactly say, what you said it says. The part about extended/protruding tip plugs may be what you took it to mean, however that's not what it says or is intended to mean.
In the context, as it's written, there's no denotation about heat ranges being different for extended vs standard plugs.
It just explains how the plug absorbs and dissipates heat.
Again, I have no dog in this, my mind is open to all sides of the discussion, and I appreciate you and your posts.
Thank you for posting it in context. I appreciate it.
-Seth-
I believe based on what they wrote and applying common sense, projecting the tip, which they state is the hottest part of the plug, into the cylinder that is already at high pressure isn't a good idea and puts you closer to the threshold for detonation/preignition. When there is no downside to running a non-projected plug, why not? More cushion from detonation.
06-03-2017, 04:35 PM
#44
9 Second Club
I find that hilarious considering NGKs own website specifically states extended tip plugs by definition are hotter than there non extended tip counter parts and put you closer to the detonation threshold. I've done all the research I care to and came to the conclusion that extended/projected tip plugs aren't for me. I don't go 200mph....but also don't have meth on the car which is a huge advantage. I'll stick with what works for me and everyone can stick with what works for them.
06-03-2017, 04:44 PM
#47
i found that in my searches too...pretty cool ready and had comparisons of the old school vs new school on putting as hot of a plus in vs as cold of a plug in. I swear I read somewhere that having too hot of a plug will also act like advancing ignition.
06-03-2017, 05:06 PM
#48
If you picture the extreme opposite......wrong plug with the gap up inside the threads, it would retard the timing.
FWIW, I also don't wish to start a pissing match about plugs. I find the discussion fascinating.
I believe the manufacturer that an 8 is an 8 whether it's a std tip or a projected tip plug.
I believe the thinking is that the longer ground strap could overheat due to it's length and cause pre-ignition. I understand the thinking.
On the other hand, I run an NGK -8 projected tip race plug, and I get the same nice timing mark that I get when I use and read the BR7's in buddies cars. Same fuel, same timing.
So I would think that if my slightly longer ground strap was overheating, the timing mark would be way down around the bend. And it isn't.
I ran TR6 when I first boosted my 5.3. At 10psi they were ok. At 15psi they were pissed off. Clearly overheated. Glazed porcelain, and the electrodes were rounded off.
Thus far I've had no issues, and see no distress in the 8 race plugs.
I'm running E80 btw. I've no desire to try pump fuel.
Ron
06-03-2017, 05:10 PM
#49
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I believe based on what they wrote and applying common sense, projecting the tip, which they state is the hottest part of the plug, into the cylinder that is already at high pressure isn't a good idea and puts you closer to the threshold for detonation/preignition. When there is no downside to running a non-projected plug, why not? More cushion from detonation.
Fact is, a non projected tip isn't going to kill anything, so go with it if it's not worth your concern. I have read accounts that claim slight performance gains with projected plugs. And accounts that completely defy the popular beliefs about projected plugs. What we believe about them may be true. Or, it may all be completely false. That's where I'm at on the whole thing anyway.
From my standpoint, I would expect that, if they make an extended tip plug in the heat range I need, it would not run hotter than a non extended plug of the same heat range. Given their literature anyway.
Could just be a wives tale, caused/started by a reputable tuner leaning an engine out too much and blaming the plug for the awful misfortune. Or a magazine prints it, and we eat that **** up like it has gravy on it. All of a sudden, forced induction automatically equals non projected plugs, for all the wrong reasons.
Could be the case anyway. Could be.
I'm not convinced one way or the other.
Last edited by SethU; 06-03-2017 at 05:24 PM.
06-03-2017, 06:13 PM
#50
I think the reference to that is the fact that the spark is a wee bit further into the chamber so it has the effect of advancing the timing.
If you picture the extreme opposite......wrong plug with the gap up inside the threads, it would retard the timing.
FWIW, I also don't wish to start a pissing match about plugs. I find the discussion fascinating.
I believe the manufacturer that an 8 is an 8 whether it's a std tip or a projected tip plug.
I believe the thinking is that the longer ground strap could overheat due to it's length and cause pre-ignition. I understand the thinking.
On the other hand, I run an NGK -8 projected tip race plug, and I get the same nice timing mark that I get when I use and read the BR7's in buddies cars. Same fuel, same timing.
So I would think that if my slightly longer ground strap was overheating, the timing mark would be way down around the bend. And it isn't.
I ran TR6 when I first boosted my 5.3. At 10psi they were ok. At 15psi they were pissed off. Clearly overheated. Glazed porcelain, and the electrodes were rounded off.
Thus far I've had no issues, and see no distress in the 8 race plugs.
I'm running E80 btw. I've no desire to try pump fuel.
Ron
If you picture the extreme opposite......wrong plug with the gap up inside the threads, it would retard the timing.
FWIW, I also don't wish to start a pissing match about plugs. I find the discussion fascinating.
I believe the manufacturer that an 8 is an 8 whether it's a std tip or a projected tip plug.
I believe the thinking is that the longer ground strap could overheat due to it's length and cause pre-ignition. I understand the thinking.
On the other hand, I run an NGK -8 projected tip race plug, and I get the same nice timing mark that I get when I use and read the BR7's in buddies cars. Same fuel, same timing.
So I would think that if my slightly longer ground strap was overheating, the timing mark would be way down around the bend. And it isn't.
I ran TR6 when I first boosted my 5.3. At 10psi they were ok. At 15psi they were pissed off. Clearly overheated. Glazed porcelain, and the electrodes were rounded off.
Thus far I've had no issues, and see no distress in the 8 race plugs.
I'm running E80 btw. I've no desire to try pump fuel.
Ron
06-04-2017, 05:42 AM
#54
9 Second Club
06-04-2017, 12:59 PM
#55
I wouldn't say gm is more well proven. Maybe just more widely used based on cost. Gm is cheaper that is all. Cometic has a new heavy duty line as well as so many choices of bore and thickness esp for ls7 setups which only have 1 gm choice.
06-05-2017, 10:58 AM
#56
9 Second Club
Just look at almost any build here....LS9's are the most common, and they work time and time again.
To me that is absolutely well proven ( and same with almost any GM MLS gasket )
Cometics ? who knows ? There may be a handful out there.
To me that is absolutely well proven ( and same with almost any GM MLS gasket )
Cometics ? who knows ? There may be a handful out there.
06-05-2017, 11:37 AM
#59
I think the reference to that is the fact that the spark is a wee bit further into the chamber so it has the effect of advancing the timing.
If you picture the extreme opposite......wrong plug with the gap up inside the threads, it would retard the timing.
FWIW, I also don't wish to start a pissing match about plugs. I find the discussion fascinating.
I believe the manufacturer that an 8 is an 8 whether it's a std tip or a projected tip plug.
I believe the thinking is that the longer ground strap could overheat due to it's length and cause pre-ignition. I understand the thinking.
On the other hand, I run an NGK -8 projected tip race plug, and I get the same nice timing mark that I get when I use and read the BR7's in buddies cars. Same fuel, same timing.
So I would think that if my slightly longer ground strap was overheating, the timing mark would be way down around the bend. And it isn't.
I ran TR6 when I first boosted my 5.3. At 10psi they were ok. At 15psi they were pissed off. Clearly overheated. Glazed porcelain, and the electrodes were rounded off.
Thus far I've had no issues, and see no distress in the 8 race plugs.
I'm running E80 btw. I've no desire to try pump fuel.
Ron
If you picture the extreme opposite......wrong plug with the gap up inside the threads, it would retard the timing.
FWIW, I also don't wish to start a pissing match about plugs. I find the discussion fascinating.
I believe the manufacturer that an 8 is an 8 whether it's a std tip or a projected tip plug.
I believe the thinking is that the longer ground strap could overheat due to it's length and cause pre-ignition. I understand the thinking.
On the other hand, I run an NGK -8 projected tip race plug, and I get the same nice timing mark that I get when I use and read the BR7's in buddies cars. Same fuel, same timing.
So I would think that if my slightly longer ground strap was overheating, the timing mark would be way down around the bend. And it isn't.
I ran TR6 when I first boosted my 5.3. At 10psi they were ok. At 15psi they were pissed off. Clearly overheated. Glazed porcelain, and the electrodes were rounded off.
Thus far I've had no issues, and see no distress in the 8 race plugs.
I'm running E80 btw. I've no desire to try pump fuel.
Ron
2. Projected Core Nose – places the spark an additional 1/8″ into the combustion chamber. Originally designed to prevent fouling by exposing the insulator/ center wire to the air fuel path and heat of the cylinder. In street applications it performs as a hotter plug at lower RPM while running cooler at higher RPM. This is due to the cooling effect of the fuel charge on the projected tip. In racing it does the same thing, however it has limitations because the core nose length and the long ground wire limit the ability to build the colder heat ranges in this configuration. If this plug could be built in a colder heat range it would be ideal for super-speedway use, but as it is its use is normally limited to short tracks, some road courses, and sometimes qualifying on the big tracks. Because it physically moves the ignition point it can more centrally locate the ignition which reduces combustion time. It can also place the ignition point in a more efficient location based on swirl. In some cases this plug has the same effect as increasing ignition timing.
06-05-2017, 11:41 AM
#60
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Actually, based on this description we should be using projected plugs...they run cooler at wot:
2. Projected Core Nose – places the spark an additional 1/8″ into the combustion chamber. Originally designed to prevent fouling by exposing the insulator/ center wire to the air fuel path and heat of the cylinder. In street applications it performs as a hotter plug at lower RPM while running cooler at higher RPM. This is due to the cooling effect of the fuel charge on the projected tip. In racing it does the same thing, however it has limitations because the core nose length and the long ground wire limit the ability to build the colder heat ranges in this configuration. If this plug could be built in a colder heat range it would be ideal for super-speedway use, but as it is its use is normally limited to short tracks, some road courses, and sometimes qualifying on the big tracks. Because it physically moves the ignition point it can more centrally locate the ignition which reduces combustion time. It can also place the ignition point in a more efficient location based on swirl. In some cases this plug has the same effect as increasing ignition timing.
2. Projected Core Nose – places the spark an additional 1/8″ into the combustion chamber. Originally designed to prevent fouling by exposing the insulator/ center wire to the air fuel path and heat of the cylinder. In street applications it performs as a hotter plug at lower RPM while running cooler at higher RPM. This is due to the cooling effect of the fuel charge on the projected tip. In racing it does the same thing, however it has limitations because the core nose length and the long ground wire limit the ability to build the colder heat ranges in this configuration. If this plug could be built in a colder heat range it would be ideal for super-speedway use, but as it is its use is normally limited to short tracks, some road courses, and sometimes qualifying on the big tracks. Because it physically moves the ignition point it can more centrally locate the ignition which reduces combustion time. It can also place the ignition point in a more efficient location based on swirl. In some cases this plug has the same effect as increasing ignition timing.