[/color][align=center]5 WAYS TO BREAK THE NOSE OF A CRANKSHAFT[/size][/align][align=center][/align][align=left]In recent months we have had numerous questions and issues raised about the nose of the crank and what can cause it to break.[/align][align=left]What we have found is that in most cases the crankshaft gets the blame for such failures. But in fact, it is additional parts used, and the additional machining required, that is the cause of failure.[/align][align=center][/align][align=left]1. [/size]IMPROPERLY MACHINED CRANK GEARS [/font][/align][align=left][/align][align=left]A. Chamfer machined at wrong angle.[/align][align=left]B. Chamfer machined with too small an angle.[/align][align=left]C. Belt drive gears.The seal sleeve bottoms to the face of the main before the interface of the gear bottoms against the step in the nose of the crank. [/align][align=left][/align][align=left]All of the above prevents the crank gear from bottoming against the step on the nose of the crank. This leaves a gap between the gear and the step, which allows the crank to flex ...A fatigue crack starts. SNAP!!!! The crank breaks.[/align][align=left][/align][align=left][/align][align=left]2. DAMPERS WITH MOVING INERTIA WEIGHTS[/align][align=left]Fluid, *****, springs, inertia rings with rubber O-Rings, etc. Can you balance a wheel on your race car if the tires are flat???? How can your rotating assembly be balanced if to quote one manufacturer," These units (Dampers) should not be on the crank for balancing as the inertia weight may not be centered until the engine starts. "NEWS FLASH!!!! Centrifugal force will always take the inertia weight off center no matter what RPM. Your assembly is never balanced. TELL TALE SIGN!!!! Metal transferred on nose outside diameter and damper internal diameter ...A fatigue crack starts. SNAP!!!! The crank breaks.[/align][align=left][/align][align=left]3. EXTERNAL BALANCE vs. RPM[/align][align=left]Rotating weight multiplies as RPM increases. Engines have heavier or lighter balance weights and larger or smaller noses. RPM above 5500 is more risky on a Small Block Chevy than a Big Block Chevy. However, as RPM’s go up, the weight more and more wants to leave the crank due to centrifugal force. Do not be surprised if at some point fatigue sets in and the nose comes off.[/align][align=left][/align][align=left]4. DRIVES EXTENDING BEYOND THE NORMAL DISTANCE ON THE NOSE Multi-stage oil pumps, blowers, etc all have belt drives that require torque taking off at 90 degrees to center line of the crank. More torque is necessary for driving these things and further away from main bearing support all leads to multiple of leverage wiggling the nose. Fatigue sets in, nose breaks, blower stops. The Small Block Chevy has the smallest diameter nose and the weakest of all. Note: Blowers take substantially more 90 degree torque than dry sump pumps, therefore, more likely to break noses. Not recommended for Small Block Chevy. If a blower is being used, use a crank with a Big Block nose[/align][align=left][/align][align=left][size=4]5. IMPROPER BALANCING TECHNIQUE[/align][align=left]The counterweights on a crankshaft are designed to work all together as a system within a certain bob weight range. To correct the balance on a crank where the counter