spark plug gap and torque needed

[ParadiseXJ]

:doh:

Plug gap is 35 (don't know exactly where the decimal point goes, always has been, most plugs come pre-gapped but always worth checking. If they are at 34 or 36...it won't make a huge difference.

gudentight

:lecture:

For those of you that are language challenged...or don't speak Swiss, Austrian or German.

This the the proper torque spec. I've used it on every single vehicle I've ever owned including the 48' Packard.

You could spend a bunch of time debating this and overthinking it and I'm sure that there in fact IS a torque spec...but really?

Good and tight...or enough to slightly crush the washer...remember you'll have to remove them some day too, and I've heard of plugs blowing out. Use anti-sieze, but use it sparingly.

Good and tight.

 

[Sidewinder CC]

:doh:

Plug gap is 35 (don't know exactly where the decimal point goes, always has been, most plugs come pre-gapped but always worth checking. If they are at 34 or 36...it won't make a huge difference.

:lecture:

For those of you that are language challenged...or don't speak Swiss, Austrian or German.

This the the proper torque spec. I've used it on every single vehicle I've ever owned including the 48' Packard.

You could spend a bunch of time debating this and overthinking it and I'm sure that there in fact IS a torque spec...but really?

Good and tight...or enough to slightly crush the washer...remember you'll have to remove them some day too, and I've heard of plugs blowing out. Use anti-sieze, but use it sparingly.

Good and tight.

You'll be back...

:helpme:

 

[Ecomike]

I am pretty sure it requires special tools and years of experience. Probably a five thousand dollar service where he is from, after all the world revolves around NYC...

LOL!!!!

 

[joe_peters]

Reasons why I torque spark plugs to specs:

1. KNOCK SENSORS. Yes, it can make a difference.

2. Stripped threads in heads.

3. Anal retentive or OCD.

4. Spark plug gap distortion.

5. All of the above.

From NGK's website, posted here under the copyright "Fair Use Rules":

Torque is one of the most critical aspects of spark plug installation. Torque directly affects the spark plugs' ability to transfer heat out of the combustion chamber. A spark plug that is under-torqued will not be fully seated on the cylinder head, hence heat transfer will be slowed. This will tend to elevate combustion chamber temperatures to unsafe levels, and pre-ignition and detonation will usually follow. Serious engine damage is not far behind.


An over-torqued spark plug can suffer from severe stress to the Metal Shell which in turn can distort the spark plug's inner gas seals or even cause a hairline fracture to the spark plug's insulator...in either case, heat transfer can again be slowed and the above mentioned conditions can occur.


The spark plug holes must always be cleaned prior to installation, otherwise you may be torquing against dirt or debris and the spark plug may actually end up under-torqued, even though your torque wrench says otherwise. Of course, you should only install spark plugs in a cool engine, because metal expands when its hot and installation may prove difficult.


My .52 cents worth on the subject.

 

[Talyn]

Head bolts are around 120 ft lbs.

110 ft lbs except #11, which is 100

Yes, anti seize affects the torque value

It also affects heat transfer thus the heat range. I've heard that Milk of Magnesia helps with seizing, but doesn't affect the heat range.

why lap your valves by hand when you can just pour sand into the cylinders and let the engine do it for you?

No no.. that is for a home port job... kind of like extrude honing.