18-11-2018, 04:46 PM
Rob, you are looking for a clear ring, which you are only likely to get if the shaft is suspended e.g. from a bit of string.
But...it's not a reliable test, and consider what's at stake (at best, you throw away a perfectly good crankshaft; at worst, you blow your engine to bits).
Buy a dye penetrant crack test kit, which will set you back 25 quid or so, follow the instructions.
If it flags up any clear cracks then you know what to do.
If you are unsure of the result, try it again.
Any that pass, or that you're still not sure about, take them to a specialist and get them crack tested by magnetic particle inspection (MPI).
DP is most effective at finding surface cracks. MPI can pick up cracks just below the surface where DP won't see them.
If a shaft passes both tests you can proceed with reasonable confidence.
But...it's not a reliable test, and consider what's at stake (at best, you throw away a perfectly good crankshaft; at worst, you blow your engine to bits).
Buy a dye penetrant crack test kit, which will set you back 25 quid or so, follow the instructions.
If it flags up any clear cracks then you know what to do.
If you are unsure of the result, try it again.
Any that pass, or that you're still not sure about, take them to a specialist and get them crack tested by magnetic particle inspection (MPI).
DP is most effective at finding surface cracks. MPI can pick up cracks just below the surface where DP won't see them.
If a shaft passes both tests you can proceed with reasonable confidence.