Humm,

In a bolt and nut combination, if you torque the bolt vs torquing the nut- you will get a difference in preload.

Correction: Torque wrenches are LESS accurate than using angle. PERIOD. 15% variation in preload(force in the bolts). Some really big bolts (3-4inch shanks) will have a small hole drilled down the middle, then you can get delta L using a micrometer to get the preload correct. Angle is about plus or minus 5 %.

You can make some stiffness assumptions and calculate the preload of the current setup vs the new studs. I'm assuming they are going to be 160 ksi or 180 ksi studs?

Stretch bolts were first employed in aviation for more consistent preload. I'd suspect reverting to the old technology you may increase your chances of headgasket failures.

These engines being Alumium head/Iron blocks will always have different coefficent of expansion differences which will work the joint regardless of the fastener selected. I'd bet headgasket life will not be much better.

Torque should be a function of joint stiffness required.... ARP vs MB.

Michael

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Michael McGuire
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