Bearing cap cavitation on Wartsila engines
As you might know, we’ve got multiple ex-Wartsila Senior Service Engineers on the Bartech team.
And as a result, we’ve got some fascinating case studies showing how issues experienced on-site can be resolved or prevented on various engine types.
During planned maintenance on one of the first Wartsila dual fuel 9L 50DF engines, our engineer came across a very unusual issue that – at the time – had never been recorded before.
The discovery was made after the field service engineering team had removed all the pistons from the engine and started to remove the shim from each big end bearing upper cap.
On removal of the shim, signs of cavitation were found on the bearing block lube oil cooling galleries, visible in the picture below:
What made this case unique was that this was localised cavitation, with nothing visible on the shim (as below), so a full RCA was carried out.
The root cause analysis established the diameter of the central hole on the bearing caps was too small and this was creating a harmonic pulsation of the lube oil pressure from the driven pump.
All big end bearing caps were manually machined to remove the cavitation and a new type of bearing cap shim with a larger diameter was installed.
A further inspection was carried out after 8000 running hours and no signs of cavitation were noted.
If you have an engine – Wartsila or other – that will benefit from this level of technical knowledge, get in touch we’d be happy to assist – hit reply and let’s talk.