Re: Tensioner vs. Detensioner

[Jerry in Houston <glewis4457@xxxxxxxxx>]

<<From: Mark Denovich <mark@domain.elided>
Subject: Re: V6 Bent Valve Mystery

The mechanical tensioner is extremely intolerant of 
having the engine rotate backwards.>>

I keep seeing this device referred to as a
"tensioner", as if its vasic job is to provide tension
to the cam belt.  It is just the opposite, its job is
to relieve the excess tension that would be put on the
cam belt by the expansion of the aluminum engine as it
warms up. Rather than an poor detensioner design, I
think the fundamental problem of belt slippage is how
much (or how little) of the cam drive is actually in
contact with the drive belt... i.e. too little contact
which allows slippage under certain extreme
conditions.  When I replaced the detensioner on my
GTV-6 the folks at Vicks, where I bought the part,
recommended slightly overtightening the belt during
the intitial installation setup. Works so far.

Jerry in Houston
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