Re: Flatheads & Land speed records

[adh@xxxxxxxxxxxxxxxxx (Sandwich Maker)]

" From: "Larry R. Daum" <mramc@xxxxxxxxxxx>
" 
" 
" 
" 
" The V-6 Buicks that ran Indy for time were also
" very but never seemed to hold together much like the AMC Indy V-8
" unfortunately. 

i don't recall the buicks but i do remember the very high profile
penske/chevy v6 effort.  the cars were rocketships all month and
easily swept the front row, and looked like they'd lap the field
before the race ended, but none of them lasted longer than 50 miles.
post-race analysis: crankshaft flex wiped the center mains out.

but they were balanced, right?  of course they were balanced, but like
most crank balance jobs they were balanced as a unit.  this lets an
unbalance at one point counter an opposing unbalance at another point,
and works if you assume the crank is infinitely stiff.  this is
adequate at street rpms, but real cranks aren't infinitely stiff and
those v6 cranks bent like cooked spaghetti under the unbalance forces
pulling them in different directions.  they should've balanced each
throw independently, as if it were the only one, with counterweights
on each side.  that runs the crank weight and rotating inertia up, but
the other approach didn't work did it...

i saw a bmw six in for rebuilding last year, at my friend's engine
shop.  12 counterweights.  fully machined too.
________________________________________________________________________
Andrew Hay                                  the genius nature
internet rambler                            is to see what all have seen
adh@xxxxxxxxxxxxxxxxx                       and think what none thought