silicone on through bolts...

[vash]

didnt want to steal any thunder on the 2.7 assembly thread, so i will start another.

doesn't adding silicone sealant or silicone lube on the fastener affect the tension in the bolt? because a slippy-er connection would affect the torque right? you could affectively over-torque the connection. no that is not right, the torque would be correct, but the tension would be over tensioned. right?

cliff

[911pcars]

Probably. To lubricate a threaded fastener, use anti-seize compound. Most torque tables assume the threads are lubricated with "regular" lube unless stated otherwise. Anything slicker (moly, silicone, etc.) will cause the tension to be higher than specified.

Using silicone to seal the threads is another matter. Maybe depends on the application. Anything specific in mind?

Sherwood
http://members.rennlist.org/911pcars

[vash]

i was just reading the other thread about the through bolts. it probably is not a big deal because the torque values are relatively low, so the error would be in consequential.

[HawgRyder]

I found some washers through McMaster-Carr that have nitrile or some such on them.
They are made to seal the hole when tightened under the head of a bolt or nut.
According to the package..they are good for 550 deg F which is the temp for silicone...so I might try them on all the relevent bolts.
Bob

[Tim Walsh]

Bob,
I know I"m missing something but Are they beveled like the OE Washers? Otherwise they won't have room for the O ring.

[HawgRyder]

They are quite thin...and they have the O-ring sort of built in (bonded) to the metal part.
Like I stated...I'm not sure if I'm going to use them...it's tempting...and they come in all the metric sizes.
I think that in the decades since these cars were designed...there must be advances in sealing that were not available back then.
Bob