Originally Posted by user52165
Originally Posted by A_Harman
Originally Posted by tundraotto
Originally Posted by JOD
Originally Posted by A_Harman
Originally Posted by tundraotto
Originally Posted by JOD
NissanMaxima said:
"torque angle" vs. torque wrench comparison
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Originally Posted by hallstevenson
Originally Posted by NissanMaxima
....the "torque angle" method can be used. For the plug I used, they say 1/2 to 2/3 of a turn will produce their recommended torque of 18-21.6 lb ft of torque.
When do you 'start' the 1/2 to 2/3 of a turn ? That's the tricky part. When it's "snug" ? What does "snug" mean ? Three different people will have three different levels of snug, I'll bet.
This is exactly the issue isn't it?
I try and use a decent length extension bar and tighten the spark plugs tight as I can by hand using the extension bar like a screwdriver, then turn 1/4 of a turn with a ratchet. I also use ceramic grease on the threads to stop any issues with seizing. I find spark plugs are something you should/can do more by 'feel' than torque setting.
Originally Posted by NissanMaxima
....the "torque angle" method can be used. For the plug I used, they say 1/2 to 2/3 of a turn will produce their recommended torque of 18-21.6 lb ft of torque.
When do you 'start' the 1/2 to 2/3 of a turn ? That's the tricky part. When it's "snug" ? What does "snug" mean ? Three different people will have three different levels of snug, I'll bet.
This is exactly the issue isn't it?
I try and use a decent length extension bar and tighten the spark plugs tight as I can by hand using the extension bar like a screwdriver, then turn 1/4 of a turn with a ratchet. I also use ceramic grease on the threads to stop any issues with seizing. I find spark plugs are something you should/can do more by 'feel' than torque setting.
Originally Posted by hallstevenson
Originally Posted by NissanMaxima
....the "torque angle" method can be used. For the plug I used, they say 1/2 to 2/3 of a turn will produce their recommended torque of 18-21.6 lb ft of torque.
When do you 'start' the 1/2 to 2/3 of a turn ? That's the tricky part. When it's "snug" ? What does "snug" mean ? Three different people will have three different levels of snug, I'll bet.
Its impossible to convey a feeling in written word hence the 1/4 turn or whatever. I use the same 7" ratchet I always used for plugs and crush the washer then "snug" it.
Tapered seat plugs get a bit more than snug but not much. Many torque wrenches are at their lower settings and inaccurate anyway and even a smaller one are many times too difficult to get good access for smooth straight line operation.
I use never seize so any torque spec is out the window right off the hop, add to that slightly dirty threads and its a lost battle, I don't bother.
In the ideal world a straight shot at the plugs, cleaned threads and no never seize, an accurate low spec tool then sure you can get that OCD, how much benefit you really get is debatable.
Originally Posted by NissanMaxima
....the "torque angle" method can be used. For the plug I used, they say 1/2 to 2/3 of a turn will produce their recommended torque of 18-21.6 lb ft of torque.
When do you 'start' the 1/2 to 2/3 of a turn ? That's the tricky part. When it's "snug" ? What does "snug" mean ? Three different people will have three different levels of snug, I'll bet.
Its impossible to convey a feeling in written word hence the 1/4 turn or whatever. I use the same 7" ratchet I always used for plugs and crush the washer then "snug" it.
Tapered seat plugs get a bit more than snug but not much. Many torque wrenches are at their lower settings and inaccurate anyway and even a smaller one are many times too difficult to get good access for smooth straight line operation.
I use never seize so any torque spec is out the window right off the hop, add to that slightly dirty threads and its a lost battle, I don't bother.
In the ideal world a straight shot at the plugs, cleaned threads and no never seize, an accurate low spec tool then sure you can get that OCD, how much benefit you really get is debatable.
Oh yeah all the time, NGK plugs are plated yada yada yada. I figure I'll just wait till they get one stuck and then come here looking for advise on how to get it out then tell them how. LOL
Fact is the plating is all well and good it does help but in cold climates (sometimes referred to as the rust belt) there is a lot more moisture in the exhaust gases and for a much longer duration. It isn't so much moisture coming at the plug from above but rather below where the threads have no sealing surface/gasket.
This over many months and years can overpower the plating to some extent and you end up with seized plugs. I have come across many engines with side feed injectors that commonly on some makes run really fat when cold (fuel dilution is also an issue with these), many of them had plugs so tight I didn't know if I would get them out, plated NGK included.
Fact is the plating is all well and good it does help but in cold climates (sometimes referred to as the rust belt) there is a lot more moisture in the exhaust gases and for a much longer duration. It isn't so much moisture coming at the plug from above but rather below where the threads have no sealing surface/gasket.
This over many months and years can overpower the plating to some extent and you end up with seized plugs. I have come across many engines with side feed injectors that commonly on some makes run really fat when cold (fuel dilution is also an issue with these), many of them had plugs so tight I didn't know if I would get them out, plated NGK included.
Originally Posted by AVB
NGK isn't concerned about torque. They are concerned about how much you crush the washer. They just want it to seal and not blow out. If you had chased the threads before installing the spark plugs, you probably could have screwed them just a little bit deeper and would have reached your torque with a little less angle.
It's not worth worrying about, you are within the acceptable range. You aren't going to damage the threads, just the degree of how much you chrush the washer. Notice that they gave a range of degrees and the manual gives a range of torque. If, instead of concentrating on a specific torque value, you used the recommended 1/2-2/3 turn. I believe you would find that it would fall within range of torque specified in the manual.
AVB ... what you said helped me understand this better. Supposedly 18 to 22 lb ft is achieved with the 1/2-2/3 turn so that would imply 18 lb ft would be achieved at 1/2 turn and this is what concerned me in the first place as the torque wrench didn't click until approximately 3/4-7/8 turn.
After all these helpful comments, I went back to the NGK site and it does indeed recommend cleaning both the spark plug "hole" and the threads. I meticulously cleaned the actual gasket area using paper towels carefully wrapped around a long-handled screwdriver with isopropyl alcohol on them, but I did not mess with the threads. I thought about that, but didn't want to introduce grease into the threads as I understood thread chasers use grease to catch the debris, and I figured without the grease, any debris would fall into the cylinder. Plus, I have not seen recommendations to clean the threads on any other manufacturer site etc. unless they are damaged or rusted for example. Do folks here actually use a thread chaser for maintenance changes of spark plugs if there is no heavy debris or rust? Of interest is the NGK youtube video does not say anything about cleaning threads. Also I found it interesting to me that the NGK site says debris in the threads can result in under torquing. This is what I would surmise since anti-seize can result in over-torque, it is logical any "inhibitor" could cause under-torque.
https://ngksparkplugs.com/en/resources/spark-plug-installation
https://www.ngk.com/learning-center/article/522/plug-torque-settings
http://www.ngk-sparkplugs.jp/english/techinfo/qa/q18/index.html (this one is for hallstevenson regarding when to start the 1/2-2/3 turn which NGK says is finger tight, which I did by just using first rubber hose and then just the extension)
https://www.youtube.com/watch?v=M3myx2trNUo
In the end, I wish I had set my wrench to the minimum torque spec of 14 ft lb and see where that landed me in terms of rotation but I put my faith in the factory service manual which mentions nothing about cleaning threads as well as my new split beam torque wrench. But I try and tell myself like AVB said that hopefully the extra bit of rotation only crushed the washer perhaps more than NGK would prefer.
NGK isn't concerned about torque. They are concerned about how much you crush the washer. They just want it to seal and not blow out. If you had chased the threads before installing the spark plugs, you probably could have screwed them just a little bit deeper and would have reached your torque with a little less angle.
It's not worth worrying about, you are within the acceptable range. You aren't going to damage the threads, just the degree of how much you chrush the washer. Notice that they gave a range of degrees and the manual gives a range of torque. If, instead of concentrating on a specific torque value, you used the recommended 1/2-2/3 turn. I believe you would find that it would fall within range of torque specified in the manual.
AVB ... what you said helped me understand this better. Supposedly 18 to 22 lb ft is achieved with the 1/2-2/3 turn so that would imply 18 lb ft would be achieved at 1/2 turn and this is what concerned me in the first place as the torque wrench didn't click until approximately 3/4-7/8 turn.
After all these helpful comments, I went back to the NGK site and it does indeed recommend cleaning both the spark plug "hole" and the threads. I meticulously cleaned the actual gasket area using paper towels carefully wrapped around a long-handled screwdriver with isopropyl alcohol on them, but I did not mess with the threads. I thought about that, but didn't want to introduce grease into the threads as I understood thread chasers use grease to catch the debris, and I figured without the grease, any debris would fall into the cylinder. Plus, I have not seen recommendations to clean the threads on any other manufacturer site etc. unless they are damaged or rusted for example. Do folks here actually use a thread chaser for maintenance changes of spark plugs if there is no heavy debris or rust? Of interest is the NGK youtube video does not say anything about cleaning threads. Also I found it interesting to me that the NGK site says debris in the threads can result in under torquing. This is what I would surmise since anti-seize can result in over-torque, it is logical any "inhibitor" could cause under-torque.
https://ngksparkplugs.com/en/resources/spark-plug-installation
https://www.ngk.com/learning-center/article/522/plug-torque-settings
http://www.ngk-sparkplugs.jp/english/techinfo/qa/q18/index.html (this one is for hallstevenson regarding when to start the 1/2-2/3 turn which NGK says is finger tight, which I did by just using first rubber hose and then just the extension)
https://www.youtube.com/watch?v=M3myx2trNUo
In the end, I wish I had set my wrench to the minimum torque spec of 14 ft lb and see where that landed me in terms of rotation but I put my faith in the factory service manual which mentions nothing about cleaning threads as well as my new split beam torque wrench. But I try and tell myself like AVB said that hopefully the extra bit of rotation only crushed the washer perhaps more than NGK would prefer.
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