Re: <All> Head bolt torque tips

[Mark Byrum <markbyrum@erols.com>]

Al Powell wrote:
> 
> Hot Rod :
> 
> 1)  When torquing head bolts, always use a washer under the bolt,
> even on cast iron heads.  Also, put a drop or two of oil between the
> washer and the bolt head.  This lessens friction and ensures a more
> accurate reading from the wrench.
> 
> 2)  AFter torquing all the head bolts, let them sit for an hour or
> so, then back each bolt off about 1/4 turn, and re-torque.  If you
> mark each bolt relative to the head, you will find the bolts turn
> farther the second time it's tightened to the same torque spec.  This
> evidently "overcomes the breakaway torque" required to reach
> the final torque setting the first time.
> 
> Quattro:
	I read somewhere that adding lubricant to the threads of a bolt being
torqued interferes with it reaching the appropriate torque.  Unsure why
that was, unless the torque numbers are designed around a "clean but
dry" bolt and lubricating the threads lulls one into thinking the
appropriate level has been reached until the threads strip.  It's a
thought.
	markbyrum@erols.com
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