Re: Angle Torque & head bolts

["David Teitelbaum" <jtrealty@xxxx>]

Before reusing head bolts or any other critical fastener (like rod
bolts) they should be measured for length and at several places along
the bolt for diameter. If you have no idea of the history of the
engine or are considering upgrading the engine's performance then it
is penny wise and pound foolish not to upgrade the fasteners. On the
Delorean, IMHO after using the angle method of torqueing which puts
the fastener much closer to the elastic limit, it is not a great idea
to reuse the head bolts. The idea behind torqueing of bolts is to
impose a stress on the fastener higher then the stress it will see in
service so it cannot go through cycles of stress which will result in
fatigue. This works until you try to reuse the fastener in which case
you are now cycling it through the stress of multiple torqueings. 
David Teitelbaum
vin 10757




--- In dmcnews@xxxxxxxxxxxxxxx, "miltdanfoss" <d@xxxx> wrote:
> There is a very interesting article in this month's Popular Mechanics 
> about angle torqueing.
> 
> It is worth mentioning that the article states that it is a 
> completely different method than the regular kind of torqueing and 
> this method uses a different material bolt for the head bolts and 
> that part of what one is doing is stretching the bolt, and therefore 
> they shouldn't be reused because there is too great a risk with 
> snapping them.
>