O-320 3.5 crank speed vibration
Hi,
I tried to balance a prop on a O-320 on a RV-6 the other day and could
not because other large vibrations were present.
Im summary, I got:
0.7 IPS at 0.5 crank RPM
0.2 IPS at crank RPM
0.5 IPS at 3.5 crank RPM
The vibration levels at the other multiples of 1/2 crank were all
relatively small.
I can find lots of info on the web re 1/2 crank vibration and its
causes but I can find nothing on 3.5 crank and I am puzzled as to why
it is so high.
Is it normal for this kind of engine?
Thanks,
Mark
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