When these taper seat plugs were first fitted to the then new Ford DFX F1 engine in 1960's the mechanics were threatened with dismissal for not using torque spanners especially set for the plugs.
Apparently Graham Hill had several engine failures due to plugs breaking which prompted this course of action.
Just yesterday I had to remove a couple of plugs for tune up purposes and #1 was super tight. I remembered this thread at the time and feared it was going to happen to me. I'm so glad it didn't, but....
Is there a precaution we/I can take so that it doesn't?
Sundowner wrote: ↑Sat Mar 24, 2018 9:04 pm
Just yesterday I had to remove a couple of plugs for tune up purposes and #1 was super tight. I remembered this thread at the time and feared it was going to happen to me. I'm so glad it didn't, but....
Is there a precaution we/I can take so that it doesn't?
Rob
Yes, don't overtighten them when putting them back and treat the threads to a light smear of copperslip. I've also found in the past the plugs can be tight if the tubes have had oil sitting in them for a time, but that could be coincidence.
Also, as in the case of the car it happened to me with, don't leave it sitting in a hedge for 30 years with the weather able to get beneath the bonnet!
Sundowner wrote: ↑Sat Mar 24, 2018 9:04 pm
Just yesterday I had to remove a couple of plugs for tune up purposes and #1 was super tight. I remembered this thread at the time and feared it was going to happen to me. I'm so glad it didn't, but....
Is there a precaution we/I can take so that it doesn't?
Rob
Yes, don't overtighten them when putting them back and treat the threads to a light smear of copperslip. I've also found in the past the plugs can be tight if the tubes have had oil sitting in them for a time, but that could be coincidence.
Also, as in the case of the car it happened to me with, don't leave it sitting in a hedge for 30 years with the weather able to get beneath the bonnet!
Thanks for that.
I've never overtightened spark plugs. It was drummed into me by my father when I was a teenager. But I have noticed that they tighten up after they've been in use, especially in the Sprint Heads.
I've owned several aluminium headed cars over the years (mostly Japanese) but none seemed to tighten up as much as these do.
I haven't used any kind of anti seizing compound on spark plugs before, but I will from now on.
Thanks again,
Cheers,
Rob