Cyl Head Torque
HDF Community Team
Joined: Jun 2006
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From: san antonio
Tourer
Joined: Dec 2007
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Torque figures are subjective as they get higher. The fit of the nut to stud, the lubricant used and the surface finishes all have an effect on friction. That's why the factory specs say to torque to 16 ft lbs and then go 90 degrees. The threads are all the same so going 90 degrees will give a true distance and pressure on the gasket. If you use the torque numbers, the variables mention before will cause an uneven torque to the gasket. IMO the factory way is the best. Be sure to lubricate the threads and between the head and the washer on the nut. This will make the 16 ft lbs more accurate. Use engine oil since the specs are designed for it.
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Intermediate
Joined: Dec 2008
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Torque figures are subjective as they get higher. The fit of the nut to stud, the lubricant used and the surface finishes all have an effect on friction. That's why the factory specs say to torque to 16 ft lbs and then go 90 degrees. The threads are all the same so going 90 degrees will give a true distance and pressure on the gasket. If you use the torque numbers, the variables mention before will cause an uneven torque to the gasket. IMO the factory way is the best. Be sure to lubricate the threads and between the head and the washer on the nut. This will make the 16 ft lbs more accurate. Use engine oil since the specs are designed for it.
Elite HDF Member
Joined: Jun 2008
Posts: 4,109
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From: Connecticut
I appreciate your feedback and can't argue with the technical logic, other than it assumes your starting point of 16 ft lbs is equal accross all four. I'd certainly like to believe HD's mfg is good enough that "fit" variances should be very tightly controlled. I guess I have just never seen this before acrross a pretty wide variety of engines, including air cooled aircraft stuff. Again, appreciate the feedback...
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