[alexiskai]

Originally Posted by Pete

I have some questions.
1- Why did you use that particular thread lube?
2- Why did you use stainless steel for the spacer block?
3- Why did you use plated standard grade 8 nuts instead of hard high nuts like Larry does?
4- Why did you NOT use a hard heavy machine washer under the nut?
5- Why did you use that torque value for testing?

1. I used motor oil, that's pretty standard as a thread lube for this application.
2. Stainless steel won’t compress as easily as mild steel. 303/304 isn't the hardest of stainless alloys, but it was what was available.
3. The Model A nuts from Mike's/Snyder's are still a high nut as compared to a regular hex nut. The original Ford nut spec is .440” high. These nuts are .437", but I felt like that was close enough. A higher nut would be better for testing to really high torque values, but that wasn't what this test was doing. Keep in mind, tests have shown that once you get beyond 7 threads, additional threads are carrying very little of the clamp load. Cadmium plating has an almost identical coefficient of friction as plain finish (0.19 vs 0.20).
4. The hard machine washer under the nut is a good idea if you can find one hard enough. But it would also have to be a close fit around the stud to eliminate the eccentric loading problem. Bottom line, I didn't think most people trying to reproduce the test would be able to reliably source a correct washer. And in the real head application there usually aren't washers.
5. 65 ft-lbs is the way the test is described on fordgarage.com and it's the spec recommended for the Super Brumfield heads. You should test to the clamp load you expect to use on your head. If you're doing a stock head on a clean deck, 55 would be fine.