fellow listees and learkers
    I found a great article about the stretch to yield hardware in this
months automotive rebuilder magazine it is also on line at
http://www.automotiverebuilder.com under feature articles. I hope this
will
clear up the confusion about the hardware on the 2.1 rods
    the bug crankshafts as everybody knows flexes. when I was building
formula vee engines that would spin up to 6k on the track flexing could
be a
problem. After all the 40 hp crank was much better at flexing than was
the 1500 or
1600 cross drilled cranks To get around this problem I always had the
center
main ground .0015 ths. below the low limit and that gave the crank the
needed
room to flex, live and see yet another race
    The first symptom of a flexing crank is that the case takes a
pounding
at the center main web. The common belief is that the crank flexes when
it is
at top dead center There is a second symptom of the bug crank flexing
that I
have never heard discussed and that is the crank center main bearing
journal
ware. I have inspected and measured lots of cranks in my time and the
one place the
bug crank shows it ware first is at the center main oiling holes. It is
not
uncommon to see 0015ths. out of round at this spot  This is not from
lack of
lubrication but a result of the crank flex then the pistons are half way
in there
travel. I have never seen any signs of this in any 1.9 or 2.1 crankshaft
that I have
measured ever.
    It is not uncommon to put a 2.1 case back into service after 150k
because the case measures fine you could not say that with any bug case
with even
1/2 that number of miles sure its been done but the person that did it
never
measured the case and sure it didnt bind until it got hot but how would
whey
know the cranks binding the only symptom of this is it ran really hot
and didnt
make allot of power
Bob Donalds
http://www.bostonengine.com
as always
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