Gram-inches to inches-per-second conversion
One comes across both sets of units in discussions of dynamic crankshaft or propeller balancing.
What is the conversion from one to the other?
Crankshafts get dynamically balanced (by specialist US engine rebuilders) to below 1 gram-inch. They leave the Lycoming factory anything up to 50 times this value, apparently.
Propellers get dynamically balanced to normally below 0.1 IPS. Static balancing alone tends to get you below 1 IPS.