Re: Chrome Head Nuts Stripping

Posted by Tim Cole On 2010/8/11 17:15:54

Lets see, the head studs on the Packard 8 are 7/16-20.

That's a pretty hefty size and should hold up pretty well. I would check the stud height using an ordinary hex nut. I would also dress the threads with a thread chaser - not a die. After that I would chuck a grade 8 bolt up in a vise and do a yield test using a good torque wrench. If the fasteners are junk then they should strip out.

I'm not doubting that crummy merchandise is being sold, but if there is a problem I would throw grade 8 nuts on the motor and run it. Acorns can be put on later.

Also, torque wrenches need to be periodically tested. I have seen torque wrenches fail a calibration test because they are certified worn out junk.