SKIDMORE TORQUE TESTER

G'Day All, JimC mentioned in another thread about the Skidmore torque tester. Curiosity got the better of me and here's a link demonstrating the tester and the difference between lubed and dry tension. I found it interesting, so hope you do!

http://www.youtube.com/watch?v=O96AUlIB ... re=related

foxy

Hadn't seen that before, pretty convincing demonstration. Beg's the question whether there can be too much lube. I've heard that using when using never-seez you should reduce torque values.

Jim H.

I would say that in order to get the full effect from torque and to keep them heads down nice and tight and to allow those head gaskets to do their job, lube the threads and faces. Particularly with mixed materials ( steel to aluminum) which when dry can promote gauling.

This is some good info, Foxy. Perhaps those frequent posts on blown head gasket will subside and our fellows can ride on down the road with more confidence in their machines.
Thanks, Foxy and JimC

jrh2020 said:

I've heard that using when using never-seez you should reduce torque values.

Jim H.

Click to expand...

I wouldn't think so. Torque value are probably assessed for prime conditions and anything less would reduce the effective force applied. I do not think the use of anti sneeze grease is applicable here. That for special stuff. Just as long as the fasteners are not dry is the key here. Is a residual film is all that is needed.

The only place rather accurate bolt tension is critical is the rod cap bolt stretch which should land between .006 and .007". The ones I measured needed a few [5-ish] lb/ft over manual spec to get over .006". That was after nuts run on/off a few times to burnish their surfaces, seat indexed smooth and a bit of lube to boot. The rest just get nipped up till crush gets crushed down to they stay put and keep leaks at bay. I do click my tongue when the micrometer reaches its mark.

They had something like this on that "Overhauling" show ( I think it was), only they were promoting some kind of lube made especially for head bolts and such. During their demonstration they compared several different lubes (and of course the stuff they were pushing produced the best results). I was told that angle torquing was invented by Mercedes engineers in order to more accurately achieve the required tension. The stretch and tension of any given type of steel at whatever length and diameter is all cataloged (in data bases now). So, at whatever thread (pitch or threads per inch) a twist of "X" number of degrees produces a known stretch and tension regardless of lube or rust.

GB