QUOTE(Rand @ Apr 11 2013, 12:13 AM)
Wait, what? About the step stud? You prefer an insert? With Loctite? Did I hear that right? Oof. Really? That's why I'm not painted.
Sarcasm aside (and I did say that you guys know more than I do
), a Time Insert is a stronger and more reliable option. If I remember correctly, several engine builders here have recommended that when heads are rebuilt that Time Serts be installed to avoid future headaches. They are along the same lines as "case savers" for Type 1s, which are installed to prevent case studs from pulling in high HP applications.
Aluminum gets brittle as it is heat cycled over and over. If you drill out a stud, re-tap the aluminum and install a step stud, is it not just a matter of time before the step stud pulls out from the same forces that pulled out the initial stud?
Finally, if a Time Sert pulls out (which I have not heard of), another can be reinstalled. If a step stud pulls out, the hole will then be large enough that it is doubtful you'll find another step stud large enough at the base, but still small enough at the stem to fit our heat exchangers.
Anyway, the point of my original post was to reassure Porschef that if he goes slow and takes the right precautions, it's not as risky as one might think. Drill straight and do NOT drill too deep. You'll be fine.