South Cerney Engineering offers crankshaft straightening on pretty much anything. An ideal service for optimising a crankshafts performance.
Sometimes a crankshaft can be bent while in service, this can be caused by extreme heat upon bearing failure occurring or when the engine is heavily overloaded. A crankshaft with a failed bearing shell and therefore heavily heated up bearing journal should ideally be checked for straightness prior to being reground.
The apparatus shown above is used for measuring and straightening crankshafts of any length and size.
To successfully straighten a crankshaft will depend on several things, namely, how much the crankshaft is bent by, whether the crankshaft has been heat treated and the construction of the crankshaft.
A crankshaft straightening jig is required to straighten a crankshaft. First the crankshaft is fitted to the apparatus, then the journals are measured to locate where the bend is. Then the crankshaft has a load applied under the journal. Applying a load alone will not straighten a crankshaft. The bearing journal fillets need to be peened to release the internal stress in the crankshaft. The crankshaft needs to be over straightened prior to grinding to compensate for the crankshaft relaxing over time.