Crankshaft Straightening Insitu

Nicol & Andrew Carry out crankshaft straightening in-situ (on site) within the engine.

If your engine has suffered heat damage perhaps caused by an oil starved crankpin or main journal (or some form of catastrophic failure) then it is also possible that your shaft may have bent slightly due to the stresses induced. If you do not know how to measure this we can check this for you.

crankshaft straightening peening slider

If the bend is not that large there is a process called crankshaft peening and machining that can usually recover the bend in the shaft to within the OEM's acceptable limits.

In most cases of heat damage the crankpin journal (big end) is the cause of the failure and it is this that we tend to concentrate our efforts on.

Firstly we machine the outer damaged skin of the crankpin to remove most of the scoring / wear and some of the hardened material. This often causes some of the built up stresses to be released and the bend to reduce.

We then peen the crankpin using a tried and tested technique to reduce the remaining stresses in the shaft. All the time we monitor the straightness to see by how much and in which direction the bend is reducing.

In many cases one peening operation and a subsequent machining and polishing of the crankpin journal will recover the situation to within acceptable OEM limits.

In some cases if the bend is significant we may need to peen and machine several times (assuming there is sufficient material available above the OEM bottom size) to recover the shaft.

If the crankpin journal is severely heat damaged an annealing (heat treatment) process can be used within the engine to reduce the hardness to an acceptable level. Note that if any cracks exist in the journal these will have to be removed prior to the heat treatment process by machining the crankpin or by localised hand grinding.

Please contact us for more information.