Tom, thanks for the info re prop.
The bearing tester may not be familiar to everyone outside the UK. It is a Dial Test Gauge held in an adaptor which screws into the spark plug hole. The engine is set with the piston nominally at top dead centre. A syringe on the end of a pipe attaches to the adaptor, and is used to create either positive pressure or a slight vacuum in the combustion chamber. The piston moves in response. The total of the conrod little end and big end 'float' is then read off the gauge.
Point is though, the reading is not a linear indicator of bearing wear or remaining life. The indication stays low for most of the life of the two bearings being tested, and then rises relatively sharply toward the end of useful life or the failure of the bearings.
I'd say it is necessary to use it very regularly if constant vigilance of bearing condition is wanted, or just a few times - say 5 engine hours apart - prior to any long water crossing for re-assurance.
Often seen adverts in the UK for aircraft or engines proudly stating very low float measurements. Meaningless. |