<VV> Comment on adjusting fan belts

[Jim Simpson]

The '65 shop manual actually has a tension specification for the fan belt.
(See Engine Tune-up 6-4.) For a new belt, it calls for 75 (+/-5) pounds and
55 for a used one.   The shop manual seems pretty emphatic about the
tension, giving instructions on running in a new belt for two minutes and
then rechecking the tension.  And while it gives an alternate approach
based upon deflection (3/8" with a 15 pound side load), it recommends
rechecking with a strand tension gauge.

The Corvair community's 50 years of experience is that is way too tight!

While few of us have fan belt tension gauges, we've learned that adjusting
the fan belt so that you can just make the alternator slip is about right.
I do happen to have a tension gauge (I bought it from the late John Moody,
a.k.a. "Mr Bent Wrench") and have used it to checked to see what that
tension actually is.  According to the gauge, it's about 20-25 pounds
tension, a third of what Chevy specified.

I don't know how Chevy came up with the tension specs, but I strongly agree
with the current consensus -- just tight enough so that you can barely make
the alternator slip.

Jim Simpson
Group Corvair