Spark plug inserts

[SchnellSchweitz]

I'm just in the process of inserting my spark plugs and noticed several do not seat well. After several last turns they seem to grab, but I'm not sure they are fully seated. Should I keep turning until I reach the specified torque or call it good where they are? Perhaps this is normal with a rebuilt engine? I'm a little afraid to torque these to the specified amount, but perhaps I need to?

(Side note: I switched from Bosch to NGK. Perhaps the Bosch plugs are slightly larger?)

Thanks for your responses in advance.

Eric J.

Extra credit: If TimeSerts were ever required for the spark plugs, is there a kit and sleeve size folks would recommend and has anyone ever done this without pulling the heads?

[MBruns]

Time sert does make a spark plug specific repair kit for 12mm and 14mm and maybe others, they work pretty good as far as installation on 911's assembled.
the tap pilots on the existing thread to begin the oversize cut then it uses the tap to pilot the counterbore tool for the small flange on the insert, we keep them in the race trailer for field repairs and inspect when the engines come down for repair. I have seen some come out with a dry plug but who knows how well they were installed
Good luck, Mike Bruns JBRacing.com

[Walt Fricke]

Eric - did you use anti-sieze?

I used to have the feeling you have on my Beetle VW engines, but never on the 911. The plugs (modestly lubricated) just go in, bottom, and get that extra yank to be sure they are seated and going to stay put.

I usually install the plugs using a short rubber hose which just fits (but tightly) over the ceramic. Helps me locate the hole and get the plug started. Normally I can spin the plug down to its seat this way, so the wrench only turns a little to get some torque. Magnetic plug holders should work like this too.

If you are worried, why not use a thread chaser for the holes which seem odd? You can take an old spark plug, cut maybe 4 slots in its threads, and run it in (with lubrication) and back out. The slots should cut any small burring, and also keep the bits in place.

[SchnellSchweitz]

I did not use anti-seize, just a dab of motor oil on the threads.

However, I took them out and inspected them and they show no signs of cross threading what-so-ever and, from what I can see, the head threads look fine.

I must just be a little over-critical here because they did finally tighten up pretty good on my second install. Not sure if I was all the way to the bottom on my first try???

Anyway... I think I'm good to go.

Thanks for the input from everyone!

Eric J.