I dont agree... When servicing an engine you have to go through some serious extra steps to get the oil off of the bolts and the threads in the block.

From a practical standpoint if it was a dry spec it would be a bear to get all of the tapped holes free of residual oil on a valve job or an engine build up.

Same goes for re torque values. Once the engine is assembled some bolts are going to end up wet with oil. If you have some dry and some wet, then you have a very uneven head preload.

IMHO the factory did not address this and its not reasonable to assume its one way or the other.

As a backyard mechanic, i have built my motors with the fasteners lubed with engine oil ( unless using ARP studs). Compared to dry you dont have as large a risk of thread damage.

As an engineer, the correct solution to this issue is to read the bolt grade assume a oil lubricated steel thread into cast iron and make sure your torque spec is within the range of the fasteners clamping capacity.

That should include the stress level change incurred as the aluminum head expands.

Since Frank has put several motors together using lubed threads, its reasonable to assume that the preload he reached is withing the fasteners capability.

A sign that you have a problem is if you get the rotation to torque become non linear, AKA- you get to a certain torque value and for a given rotation you dont get the same increase in torque. When your non torque to yield bolts yield.

Also, on most fasteners, as you use them the friction level drops off. So for a given torque, the clamping load increases with each usage. After 50 or so cycles, this stops happening.

To be reduce preload scatter you need to specify a lot of variables. That's how we got TTY.

Kevin