How Much Torque for Spark Plugs – A Complete Guide with Chart
A spark plug is the most common part of the ignition system, and it is most commonly used for transmitting electrical energy, also the most sensitive part of gasoline, air mixture. That’s why when you are going to install the spark plug; you need to be more careful for it, especially when you are trying to torque the spark plugs properly.
Many times interns are facing the most common issue is how much torque for spark plug need? And which is the perfect sizes torque wrench for which size spark plugs. Most of the time, you can see that many people aren’t using proper gripping, that’s why they fail, and 90% of the time, the spark plugs are damaged. Anyway, we come with a complete guide for related of those all question. Let’s get started on our journey.
Why Is It So Important to Torque the Spark Plugs the Proper Way?
As you may know, spark plugs are just similarly critical and sensitive as any other engine part, so installing them accurately is very important. Due to this, instead of other regular wrenches, a torque wrench is used to apply the exact amount of torque.
And to make the right amount of torque with the torque wrench, you need to set the measurement correctly. The complete chart of which we have shared is below for easy understanding.
What Happens When Too Much Torque is Applied?
If you accidentally apply extra torque to the spark plugs, then the first thing you can notice is that the thread of the spark plugs has been damaged due to the extra pressure.
There will also be internal start-up damage to the spark plugs, and there are also chances of major damage like spark plugs housing deformed, insulator cracking, etc.
Try to remove the cracked spark plugs before they are completely damaged; otherwise, your engine is likely to be severely damaged.
What Happens When Not Enough Torque is Applied?
If you apply torque at a lower level than the recommendation of spark plugs, then the first thing that will happen is that the spark plug will not sit properly on the head of the cylinder. Also, it will start to vibrate excessively during the engine. It will also delay excess heat dissipation.
It can cause a variety of engine damage, including overheating and generating noise, so refrain from over-tightening and loosening spark plugs when torquing, as well as try to apply torque with the help of an accurate measurement torque wrench.
How to Successfully Install Spark Plugs
At present, in most of the manufacturer’s books, you can see in full detail all the specifications, installation instructions, and requirements are all shared, in-depth with the image. Primary knowledge users can easily install the spark plugs without any hassles.
We have suggested a YouTube video below to make it easier to understand. As well as how much torque you can use for a spark plug, I have shared a complete chart below, which will help you a lot to apply the exact amount of torque, as well as help to avoid over tightening and loosening to protect your spark plugs from damage.
How Much Torque for Spark Plug
You can see commonly two types of torque recommendation, gasket type and other one is the tapered seat. And there are two different measurements of torque in both fields. Let’s take a look at the chart for easy understanding.
Torque Recommendations Chart for Spark Plugs
|Torque Recommendations||Thread Size||Gasket Part No||Cast Iron Heads||Aluminum Iron Heads|
|With Torque Wrench||Without Torque Wrench||With Torque Wrench||Without Torque Wrench|
|Gasket Type||10 mm||Y678||8-12 LB. FT.||1/4 Turn||8-12 LB. FT.||1/4 Turn|
|12 mm||P678||10-18 LB. FT.||1/4 Turn||10-18 LB. FT.||1/4 Turn|
|14 mm||N678||26-30 LB. FT.||1/2 to 5/8 Turn||18-22 LB. FT.||3/8 to 1/2 Turn|
|18 mm||A678||32-38 LB. FT.||1/2 to 5/8 Turn||28-34 LB. FT.||3/8 to 1/2 Turn|
|7/8″||A478||50-55 LB. FT.||1/2 to 5/8 Turn||–||–|
|Tapered Seat||14 mm||–||7-15 LB. FT.||1/16 Turn (SNUG)||7-15 LB. FT.||1/16 Turn (SNUG)|
|18 mm||–||15-20 LB. FT.||1/16 Turn (SNUG)||15-20 LB. FT.||1/16 Turn (SNUG)|
Hopefully, our complete guide has helped you a lot to know about how much torque for spark plugs, as well as our complete chart of torque wrench, has helped you a lot to understand simply. You can also read our related guide on what size torque wrench for spark plugs to get more ideas about spark plugs.
Martin A. Sims is a technician at a reputed automobile service center for the last 5 years. After studying at San Mateo College of Silicon Valley on vehicle engineering, he has started his career at age of 24. now he is spreading his knowledge among beginners around the world through thewrenches.com.