Thanks Jac, I hadn't even thought of tape.
I feel compelled to point out that the use of PTFE tape on parallel threads is a mis-use of the tape. PTFE tape itself is not a sealant; its purpose is to act as a lubricant in
tapered thread (e.g. pipe thread) to allow the joint to be torqued enough to allow the threads to deform and seal. In other words, it is a "sealing" tape only in the sense that it assists the metal threads in achieving a seal.
I'm not concerned about whether it will in fact prevent oil from migrating out the threads. What I'm concerned about is that the tape's designed effect of reducing thread friction will invalidate whatever torque figure is used for tightening the bolts. If you use a "lubricated" torque figure you may be OK, I don't know. I have no idea, nor do I know where to look, to determine the relative coefficients of friction of PTFE tape vs. oil in a steel thread environment. If you use a "dry" torque figure I'm pretty sure you will grossly overtorque the bolts.
I'm curious: this problem (oil leakage past fasteners) is old as the hills. What does a FoMoCo shop manual say to do about this? In particular, how do they say to treat the flywheel-to-crankshaft bolts?
ARP sells a sealant specifically for "wet" head bolts, but they don't mention in the context of oil leakage in different application.
Their catalog also contains the following comment that suggests Loctite would serve as a sealant in this context. But again they are talking about head bolts and coolant, not flywheel bolts and oil.
NOTE:
To ensure positive sealing of
“wet” head studs, a hardening or semi-hardening
sealant, such as Loc-Tite or Permatex,
etc. should be used. Some engine builders
employ a sealer in the coolant, such as
Aluma-Seal, Silver Seal or K&W sealer, etc.
You may also use high temperature RTV
silicone. Whatever product is used, it is
imperative that the cylinder head is installed
and torqued to proper levels BEFORE THE
SEALANT HAS CURED!
