04-21-2018, 03:50 PM
Yeah, I'm one of those guys who always just guessed at the torque. So I went out and bought a bigger torque wrench (mine only goes up to 100 in-lbs). I lapped the hub and crank (no problem) and am ready to mount the clutch. (Sorry Steve, but the chip is staying. I don't have access to a mig.)
But I also tried something new: It was pointed out to me that by letting the end of the nut bear against the shoulder inside the hub, it would be impossible to remove the hub without destroying it should the nut break. Rather I should have the head of the nut bear against the top of the hub. Makes sense to me, so I put a washer under the head of the nut so it's hitting the top of the hub rather than the internal shoulder. I tried it out using an old crankshaft and hub, went to torque it, trying for 350 in-lbs, and the nut broke somewhere around 300.
So I'm considering two scenarios: (1) - that by adding the washer, the nut is now in tension under the head rather than in compression against the shoulder, and the combination of tension and torque was too much for the nut or (2) - that the nut, which has a wall thickness of only about .035", just can't handle that kind of torque. I'm not familiar with the West Bend clutch nut. Is it beefier than the Mac nut?
I also don't know if the Margay gearbox clutch (which is what I'm using) uses the same nut as a chain clutch. Is a chain clutch nut beefier? I'd really appreciate any insight you guys can provide. I only have 3 of those nuts left. And I'd really like to get this engine going for Nicholson.
But I also tried something new: It was pointed out to me that by letting the end of the nut bear against the shoulder inside the hub, it would be impossible to remove the hub without destroying it should the nut break. Rather I should have the head of the nut bear against the top of the hub. Makes sense to me, so I put a washer under the head of the nut so it's hitting the top of the hub rather than the internal shoulder. I tried it out using an old crankshaft and hub, went to torque it, trying for 350 in-lbs, and the nut broke somewhere around 300.
So I'm considering two scenarios: (1) - that by adding the washer, the nut is now in tension under the head rather than in compression against the shoulder, and the combination of tension and torque was too much for the nut or (2) - that the nut, which has a wall thickness of only about .035", just can't handle that kind of torque. I'm not familiar with the West Bend clutch nut. Is it beefier than the Mac nut?
I also don't know if the Margay gearbox clutch (which is what I'm using) uses the same nut as a chain clutch. Is a chain clutch nut beefier? I'd really appreciate any insight you guys can provide. I only have 3 of those nuts left. And I'd really like to get this engine going for Nicholson.