Originally Posted By: Colt45ws
Originally Posted By: The_Eric
On the torque spec you listed- that may be the factory recommended value, but according to a repair service out there, a better torque is 29lbs. Yes, I understand that there are only something like 3 threads, but they claim to have tested them (3 thread heads) to around 100lbs torque without failure of the threads. I've done a few since reading their article and the plugs snug right down with no issues.
Yikes! I might be willing to go as far as 18ft. lbs but 29 is pushing it.
So I found this interesting calculator. http://www.futek.com/boltcalc.aspx?mode=metric
I put in the following data:
Major Bolt Diameter: 14 mm
Bolt Pitch: 1.25
Bolt Proof Strength: 510 MPa {I don't think this matters too much as the weak point is the head}
Recepticle Length: 12 mm {Guessed}
Recepticle Strength: 100 MPa {Used http://www.alteams.com/alteams-tech-centre/design-assistance/cast-aluminium-properties.html for reference. 100Mpa seemed close enough for sand cast non-heat treated aluminium}
Applied Tensile Load: 0 kg
k Factor: 0.2
It it came back with:
Recommended Torque
29.279 N-m
(2.98734 kg-m)
(21.593 ft-lb)
Resultant Tension:1066.2 kg
Maximum Torque
39.04 N-m
(3.983 kg-m)
(28.791 ft-lb)
Resultant Tension:1421.6 kg
So, pretty close to your 29ft.lbs figure. Maybe Ill retorque my CVPI to 21ft. lbs.
Originally Posted By: The_Eric
On the torque spec you listed- that may be the factory recommended value, but according to a repair service out there, a better torque is 29lbs. Yes, I understand that there are only something like 3 threads, but they claim to have tested them (3 thread heads) to around 100lbs torque without failure of the threads. I've done a few since reading their article and the plugs snug right down with no issues.
Yikes! I might be willing to go as far as 18ft. lbs but 29 is pushing it.
So I found this interesting calculator. http://www.futek.com/boltcalc.aspx?mode=metric
I put in the following data:
Major Bolt Diameter: 14 mm
Bolt Pitch: 1.25
Bolt Proof Strength: 510 MPa {I don't think this matters too much as the weak point is the head}
Recepticle Length: 12 mm {Guessed}
Recepticle Strength: 100 MPa {Used http://www.alteams.com/alteams-tech-centre/design-assistance/cast-aluminium-properties.html for reference. 100Mpa seemed close enough for sand cast non-heat treated aluminium}
Applied Tensile Load: 0 kg
k Factor: 0.2
It it came back with:
Recommended Torque
29.279 N-m
(2.98734 kg-m)
(21.593 ft-lb)
Resultant Tension:1066.2 kg
Maximum Torque
39.04 N-m
(3.983 kg-m)
(28.791 ft-lb)
Resultant Tension:1421.6 kg
So, pretty close to your 29ft.lbs figure. Maybe Ill retorque my CVPI to 21ft. lbs.
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