>>>*One trick we use is to set up a shop vaccum, (Having a friend nearby with a 2nd set of hands is a real asset here...)

The vaccum will draw out most of the shavings, even though they are pretty much harmless, they just blow out the exhaust when you start it..

The real problem is with the late EFI engines...They run very close to stoichiometric, which means high heat compared to a carb rig..

The steel threads act like an insulator and change the thermal transfer from the plug to the head, this is all that cools it..This is due to the thread pitch, spark plugs and helicoils are only around 75 to 80% thread contact, this leaves little air pockets around the threads..Lots of folks don't realize this, and just how close these engines are to hot spots even when tuned normally..

When we install a helicoil set or theadsert inhouse, we always suggest a one heat range drop in the spark plug for that cylinder to avoid detonation...*EB