For the crankcase and timing-side covers I'll go for Permatex.
Naaaaa; I've changed my mind.
Using Permatex it will be a nightmare to separate the crank
if ever needed in the future.
I decided to go for good old Hylomar.
This explanation of applications from Hylomar convinced me even more.
Click:
HYLOMARNote this passage:
"...
Anaerobic materials (such as those made by Hylomar or Loctite) are used on close fitting machined surfaces. They are impervious to most fluids, can be used as adhesives to provide structural strength to the joint (to augment the fasteners) and typically resist temperatures up to 150°C. They typically form a thin film along the surface of the metal and fill any surface gaps
. However, they are brittle, and can only tolerate limited amounts of vibration, torque, shock or twisting; the maximum gap fill they can manage is about 0.3mm (although they are being used to 0.5mm). Hylomar, Loctite, and other manufacturers have added flexible polymers to their methacrylates to try to flexibilise their anaerobic gasketing compounds, but this can only accomplish so much.
Silicones, on the other hand, are applied as a substantial bead on the surface of a joint. In order to be effective, they must form a relatively thick layer. Silicones are typically used to fill gaps of 1mm to 5mm. Silicones can stretch (elongation of 400% or more is common in automotive silicones such as Hylomar 100 Series Silicone RTV) and by being applied in a bead of 1mm, they can stretch to fill a maximum gap of 4mm when a joint moves. But silicones do not allow close fitting joints. Instead, joints need to be designed with chamfers or grooves if they are to optimally seal with a silicone. While slumping silicones can be applied as a thin film, then the gap fill also decreases proportionately by the size of the film, with diminishing returns...."