Folks,

I keep hearing stories about these motors stripping the sparkplug bores and then ejecting the plug thru the surrounding parts. (Grassroots motorsports forum, re: tow vehicles.)

Since I did one plug job on this motor several years ago, and don't ever want to go there again.....

Is there any factual basis for these stories?
Is there any good reason for these problems: Misassembly? Not enough bore length in the head? What?
Is there any good way to prevent this problem?

TIA,

Rog Smith

 

There's only 4 threads in the head to hold the plug.
The book says to torque to 13#.

But if you don't want to have a problem, torque to 28# and don't use any anti-size.
You wont have to worry about blowing one out that way, just don't get them cross threaded.

 

Yes it happens, twice to me.
Not properly torqueing sparks plugs is the cause from what I read here.
Can't verify that because I tourqued mine according to what I read here.
4 or 5 threads in an aluminum head is not a good thing.
It's not the end of the world, I bought a Calvan repair kit, with no reoccuring problems with repaired cylinders.
However, I hate breaking down on the road, but it happens with other things too.

 

kdson. You said You've had it happen twice. What did You torque them to? I see 13# with anti seize OR 28# and NO antiseize.

 

Been a couple of years but it was 13 and I used antisieze. I don't recall ever seeing the 28 and NO antisieze, kind of interesting.

 

do a search you will find alot of info the prob was with the pre 03 years mostly and the 2 valve heads i had one do it as well and with the milage as high as it was and the oil leaks and other things i didnt repair the heads i installed a new long block with all new inards. of course they didnt have the repair kits then either so that wasnt a option . just a fyi steer clear of the bosch plugs these motors seem to not like them go with motorcraft or autolite douple plat i am coming up change and i will antiseize them and torque just have to pinned down a number yet

 

This guy is a master teach at FORD!

Blownoutsparkplug.com Ford Spark Plug Thread Repair

51.Q: Why do you prefer 28-32 foot lbs torque instead of the factory specification?
A: Over the past few years we have heard from many of our customers that they tightened their plugs to the correct torque but they still came loose. We worked with 10 other Ford Certified Master Mechanics and concluded that 28 foot lbs of torque would be satisfactory. We have been using 28 foot lbs of torque for many years and have never had one come loose or strip out. To verify that we would not damage the original threads we used a test cylinder head with good factory threads we applied over 100 foot lbs of torque to the spark plug without any failure.

52.Q: Do you use Anti-Seize when you install new spark plugs?
A: No, we always use Motorcraft nickel plated spark plugs to stop any issues with electrolysis.

 

ThankYou phil. That pretty much clears it all up.

 

Got my info here, FAQ's:
https://www.ford-trucks.com/forums/1...ark-plugs.html
Maybe Phil's info should be stickied somewhere, if not already. If my truck wasn't already near the end of it's useful life, I would probably change the plugs again.

 

Im doing a change on my 02 Expy EB this weekend... Listen to Phil. Out of all the posts that Ive read the new spec is 25 to 30# with no AntiS using Motorcraft nickle plated plugs. Some still argue about it but this is what Im sticking with. I'll be back to bitch at Phill if I end up pulling threads...LOL Even the 2v heads can handle 80# before stripping. Also... If any of your plugs are loose when taking them out be sure to do your best to look at the threads in that hole. I believe that plugs start to get loose and leak compression through which damages the threads. In turn you will more likely to have an ejection later. This is in theory of course.