Crankshaft frictional losses are typically the smallest of the friction losses in a engine, the others being cylinder/ring friction and the valve train (you cou

Crankshaft frictional losses are typically the smallest of the friction losses in a engine, the others being cylinder/ring friction and the valve train (you could also include accessories and pumping). You can play around with the applet at http://www.wiley.com/college/mechs/ferguson356174/apps/friction/friction.html http://www.wiley.com/college/mechs/ferguson356174/apps/frict... [1] to verify this. You are right that it introduces more parts (weight, costs, reliability), which I guess is one of the reasons we haven't seen its adoption.