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  View original topic: Type 4 spark plug torque value
buzz cut hippie Tue Jul 01, 2014 5:31 pm

Am I reading the Bentley Manual correctly, it shows 22 foot lbs of torque for spark plugs on a 2000 cc type 4 engine? There seems to be a conflict between John Muir's book which states "just tight and a little more to set the gasket"

Thank you

obieoberstar Tue Jul 01, 2014 5:35 pm

22 ft/lbs is fine.

thank you for choosing the torque wrench. it is a good habit to get into.

buzz cut hippie Tue Jul 01, 2014 5:41 pm

Thank you. 22 ft/lbs seems like a lot

Tcash Tue Jul 01, 2014 7:27 pm

To link to this post
Code: [url=https://www.thesamba.com/vw/forum/viewtopic.php?p=7267149#7267149]Spark Plugs[/url]

From NGK.
Note that this is a range. On 40 year old heads I would start at 18.
The Turning Angle is: Screw in the spark plug until the Gasket meets the head. Then Turn (tighten) 1/4 of a turn.



I have used anti-seize for years with no problems. Don't get it near the tip and don't over tighten them.
http://www.ngksparkplugs.com/pdf/tb-0630111antisieze.pdf

http://www.amazon.com/Aircraft-Tool-Supply-Champion-Lubricant/dp/B005VR4F5I

http://www.permatex.com/products-2/product-categor...ant-detail

ngksparkplugsusa5 months ago
NGK spark plugs feature what is known as Trivalent
plating. This silver or chrome colored finish on the threads is designed to provide corrosion resistance against moisture and chemicals. This coating also acts as a release agent during spark plug removal. NGK spark plugs are installed at the factory dry, without the use of anti-seize. NGK tech support has received a number of tech calls from installers whom have over-tightened spark plugs because of the use of anti-seize. Anti-seize compound can act as a lubricant altering torque values up to 20 percent, increasing the risk of spark plug thread breakage.

djkeev wrote: I lubricate, There are very real problems with spark plugs pulling the threads out of the head during removal, especially when on the "warm / hot" side.
This got me curious if my opinions were based in fact or an old wives tale that so frequently gets propagated on internet forums so I pulled out one of my Bentley books, I grabbed the orange 1970 on up, it was handy.

I'll quote from Page 54, section 19.5
"Another important precaution during spark plug installation is to coat the threads lightly with a good quality anti seize compound. This coating will prevent corrosion damage to the soft aluminum threads in the cylinder head. If nothing else is available, lubricate the spark plug threads with multipurpose grease or even with motor oil. (my BOLD emphasis here but the words are in the book) NEVER INSTALL THE PLUGS DRY.
Anti seize compounds usually contain graphite, which must not come into contact with the plug electrodes or insulator. The graphite's metallic composition could short out the spark plug. Therefore, when coating the threads apply the compound with your fingertip. Don't dip the plug into the compound."
It goes on to say how to thread it in BY HAND until the gasket touches then torque each plug to 22 - 29 ft lbs.(22-29 ft lbs, is a misprint in the manual. 18-26.1 ft lbs is NGK's specification)

So, keep putting on the anti seize compound, ignore those who say not to and keep your cylinder heads threads in optimum shape. Bentley does say to use a thread chaser to clean up the hole.
Dave

Quote: RW TECH:"We use Copaslip high temp anti-sieze on the threads of all of our spark plugs. We have done extensive testing with Bosch on this, and this is about the only lube that provides the best grounding and temp transfer, while still providing the needed lubrication to get them out without damage. You do need to keep it off of the exposed chamber area as it can cause a misfire/detonation as mentioned by others, but as far as changing the heat range, it has shown VERY little to no effect. The metal particles in the lube help ensure the needed grounding (this is one of the most important grounds in the entire system) just don't get carried away with the amount to avoid chamber contamination!

We used to use EPL, engine oil ect. on the threads, but again, after testing different lubes, found the anti-sieze to be the best.

This testing all came about during the early 2000's. AC Delco was pulling back their motorsport efforts, and due to this, they started having some quality control issue's with their plugs. We started breaking pieces out of the intake valves on high duty cycle tracks (Michigan, Chicago ect), and after chasing just about everything in the book, we found the plug threads to be undersize from the sae spec. This was having a huge impact on heat transfer, and effectivly raising the heat range of the plug into the danger zone for our extended full throttle applications. This is what started all the plug and lube testing, and it is something we continue to monitor constantly.

Proper torque is VERY critical also, as thread engagement (as stated above) has a huge effect on the plugs ability to cool. Most plugs need to be torqued 15-18ft/lb, but can vary slightly with manufacture. Plugs with a compressible sealing washer should be installed, torqued, loosened and re-torqued to pre-compress the washer, thus ensuring the proper thread engagment and heat transfer during operation.

Quote: Piledriver: A wise man once told me to coat Milk Of Magnesia on plug threads in aluminum heads...

After I stopped laughing about the concept, I found it works very well, and has ~no effect of the heat range etc.
(Apparently an old turbine mechanics trick)

Quote: Hans: Hi!
I ordered some NGK B5HS plugs for my ‘73 Beetle's stock Type I
engine.
Right after that I got an e-mail about installing plugs.
Here is part of it.

Before you get started, make sure your engine is cool.

Note: I wait until it has cooled for at least 12 hours or overnight.

Before you install your plugs, it is recommended that you put
something on your spark plug threads, to aid them in installing
smoothly into the cylinder heads, and also to keep them from siezing
in the cylinder head. DO NOT use anti-sieze type products on your
spark plugs! The anti-sieze can get on the plug and cause the plug to
foul, and also affect the grounding of the plug to the cylinder head,
resulting in a fouled plug as well. We have learned over the years
that despite what manufacturers say about Never-Sieze or Anti-Sieze,
they do SOMETHING to mess up how your engine runs. The recommendation
of Aircooled.Net is a trick learned from Jake Raby at Raby's Aircooled
Technology, and that is to apply a drop or two of milk of magnesia to
the threads of the spark plug. This is not a joke, we are totally
serious! This works very well as an anti-sieze, and will not foul your
spark plugs.

I have used Permatex Anti Sieze lube for years.
Do you think this is a good idea?


buzz cut hippie Tue Jul 01, 2014 9:38 pm

Thank you for the plug torque settings guide, that is helpful information.

SGKent Tue Jul 01, 2014 9:47 pm

don't forget the anti-seize

Wildthings Sat Mar 21, 2015 9:01 am

Every day observation of plug tightening:

-Some like to leave plugs very loose so they won't strip the threads and thus the plugs blow out taking the threads with them,

-Others like to tighten them way tight so that they won't come loose and thus the threads strip or otherwise fail and the plugs blow out,

-Almost no one uses any lubricant on the threads thus after a few cycles the threads strip and/or the plugs blow out.

-Even if the plug is dropped on the floor the gap is not checked nor are the threads checked or cleaned. Hey, they are new plugs they should work fine.

-At least three plugs for each cylinder can be left laying on the cylinder head under the T4 tin without hurting anything.

-This thread is the first I have ever heard of anyone actually replacing the gaskets even though most manuals of the era say to do so. Go into an old school FLAPS and ask for spark plug gaskets and they probably won't even sell you a disposable lighter from the counter display afterwards.

oorwullie Sat Mar 21, 2015 9:09 am

if you're so insensitive and inexperienced that that you think you need this tool for spark plug tightening then i'd suggest paying someone to demonstrate exactly how a torque wrench actually works before you use it ..................... :idea:

SGKent Sat Mar 21, 2015 12:28 pm

oorwullie wrote: if you're so insensitive and inexperienced that that you think you need this tool for spark plug tightening then i'd suggest paying someone to demonstrate exactly how a torque wrench actually works before you use it ..................... :idea:

Below is what NGK has to say about tightening their 14mm flat gasket plugs in an aluminum head. 18 - 21.6 Ft lbs. Try to hit that without an accurate torque wrench.

http://www.ngksparkplugs.com/techinfo/spark_plugs/installation.asp



oorwullie Sun Mar 22, 2015 3:30 am

i've been screwing plugs into alu heads for 50 years and never used a torque wrench yet.

but then i'd never heard of NGK sparkplugs till about 15 years ago and it would also never have entered my brain to consult their website for such technical details.

you do your thing, i'll do mine. :wink:

i could even speculate that people who go to such extremes are the very ones who'll put the leads back on the wrong plugs and then run to the computer asking for advice why don't it run right! :lol:

raygreenwood Sun Mar 22, 2015 9:20 am

oorwullie wrote: i've been screwing plugs into alu heads for 50 years and never used a torque wrench yet.

but then i'd never heard of NGK sparkplugs till about 15 years ago and it would also never have entered my brain to consult their website for such technical details.

you do your thing, i'll do mine. :wink:

i could even speculate that people who go to such extremes are the very ones who'll put the leads back on the wrong plugs and then run to the computer asking for advice why don't it run right! :lol:

The NGK are no different than the Bosch in this respect.

I posted a link to thd Bosch spark plug website weeks ago. Bosch recommends the same specs as NGK....and notes that if a torque wrench is not available....finger tight in clean threads and 90° (1/4 turn) further with a wrench.
Even without websites and specs.....its an easy measurement with a simple caliper. Take a new crush washer...measure thickness. Measure thread depth and how far 1/4 turn gets you. Measure a crush washer thickness after its been properly torqued.

You will quickly find that the depth/thickness of 1/4 turn is exactly what is required to properly crush the sealing crush washer.

So yes....if you always have clean, non-gummy threads.....you can properly torque spark plugs without a torque wrench without fail. If your threads are not smooth.....first.....you should find out why and make them smooth (clean, chase or install an insert).....failing that...use a torque wrench. Ray

Wildthings Sun Mar 22, 2015 9:45 am

raygreenwood wrote: So yes....if you always have clean, non-gummy threads.....you can properly torque spark plugs without a torque wrench without fail. If your threads are not smooth.....first.....you should find out why and make them smooth (clean, chase or install an insert).....failing that...use a torque wrench. Ray

When I get to the point in life where I can't adequately torque spark plugs without a torque wrench it will be time for me to buy a Caddy, a pair of super dark wrap around sunglasses, and one of those baseball caps with the extra large brims, and drive down the road at 35mph with all the other old $hits that shouldn't be driving anymore. :cry:

Amskeptic Sun Mar 22, 2015 10:02 am

Wildthings wrote:
When I get to the point in life where I can't adequately torque spark plugs without a torque wrench it will be time for me to buy a Caddy, a pair of super dark wrap around sunglasses, and one of those baseball caps with the extra large brims, and drive down the road at 35mph with all the other old $hits that shouldn't be driving anymore. :cry:

See you at Dennys . . . they have a pureed liver and onions with tapioca pudding for dessert special on Thursdays so our dentures don't get displaced. I'll be in the Lexus LS400 that hasn't seen 2,000 rpm since I was a young pup of 75. My attempts to flirt with the waitress will be horrifically cringeworthy.

I will not torque my spark plugs to 22 ft/lbs, no way. The first installation of new plugs, I generally do the Ray Greenwood method, fingertight plus up to maybe 1/4 turn, but by and large, I seem to be always re-installing used plugs with already-crushed crush washers. In those cases, I just do a hand turn to contact + maybe 1/8th turn to around 14 ft/lbs, Calibrate your muscles by re-torquing your intake manifold nuts to exactly 14 ft/lbs, they should be checked anyway. :P
Colin

raygreenwood Sun Mar 22, 2015 11:32 am

Wildthings wrote: raygreenwood wrote: So yes....if you always have clean, non-gummy threads.....you can properly torque spark plugs without a torque wrench without fail. If your threads are not smooth.....first.....you should find out why and make them smooth (clean, chase or install an insert).....failing that...use a torque wrench. Ray

When I get to the point in life where I can't adequately torque spark plugs without a torque wrench it will be time for me to buy a Caddy, a pair of super dark wrap around sunglasses, and one of those baseball caps with the extra large brims, and drive down the road at 35mph with all the other old $hits that shouldn't be driving anymore. :cry:

I hear ya.

I always use a torque wrench.
Yes.... I trust myself that I can easily do this without one.....I just don't.

I also still mark the socket with a sharpy and watch that as well. I only use a beam type torque wrench.

18 ft lbs is pretty much max in my experience for any plug with a crush washer ..aluminum of cast iron.

Threads are threads and crush is crush. Ray

jtauxe Sun Mar 22, 2015 2:59 pm

Also, folks... just a pedantic note on unit specification:

Torque is measured in ft-lb, in-oz, or (in most of the world) N-m. That is, it is a force times a distance. In these cases, the forces are lb, oz, and N. (Weight is a force, too.) The distances are ft, in, and m.

I am seeing people use "ft/lb" above, which would be "feet per pound". Perhaps that might be how many feet of sausage you get in a pound. It has nothing to do with torque.

Learn your units!

raygreenwood Sun Mar 22, 2015 4:25 pm

jtauxe wrote: Also, folks... just a pedantic note on unit specification:

Torque is measured in ft-lb, in-oz, or (in most of the world) N-m. That is, it is a force times a distance. In these cases, the forces are lb, oz, and N. (Weight is a force, too.) The distances are ft, in, and m.

I am seeing people use "ft/lb" above, which would be "feet per pound". Perhaps that might be how many feet of sausage you get in a pound. It has nothing to do with torque.

Learn your units!

Yes....it is pedantic. Most people here know the units very well. Mostly its just a typing issue. :wink:
Ray



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