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In message <6760C5420179440F@co.albemarle.va.us> Mark Trank writes:
> Gentlemen: this was one of the responses I received. Any ideas as to
> how his troubles came about?
% In theory the valves can't touch the tops of the pistons in these
% engines at any time. But at the moment I have 5 bent exhaust
% valves that have impacted the top of the pistons in my '87 5KCSTQ.
% So much for theory.
Conventional wisdom is that there are two classes of engine;
interference and non-interference.
I expand that into three classes; non-interference, dynamic interference
and static interference.
Non-interference means what it says. Lose the timing belt, and you
coast to a halt without a timing belt. But _not_ without an engine.
Dynamic interference is the dangerous type - the engine is a
non-interfernce type on paper (i.e., in the books) and might even be
a non-interference type when within 'new' manufacturing tolerances.
But if the timing belt goes at speed, and on a worn engine - the
engine is toast.
Static interference is simply where the degree of interference is so
great that the crank cannot be hand-turned without a timing belt,
even on a new engine. The loss of the timing belt is disastrous.
I think the problem occurs in the blurring of static and dynamic.
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