What does the woodruff key do?
A#10:The woodruff key sets the flywheel’s position onto the crankshaft. This is also known as “indexing” the flywheel to the crankshaft, or making sure that that the flywheel stays in the right position relative to the crankshaft. It’s important to note that the taper of the flywheel and the torque on the flywheel nut is what keeps the flywheel mounted securely to the crankshaft. The woodruff key itself does not bear any rotational or axial load, it’s only purpose is to index the flywheel to the crankshaft when the flywheel is mounted. That said, aftermarket offset woodruff keys (often called “degree keys”) are available that change the flywheel’s position relative to the crankshaft, thereby altering the ignition timing (see Q#54 & 55). A PROPERLY installed degree key is no less reliable than a stock woodruff key (you might need to rejet!), since it’s only function is to locate the flywheel on the crankshaft, so don’t be afraid of the thinner offset of the degree key, just make sure th
