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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