PLASTIGAUGE: A few words about the clearance measurement of plain bearings and the clearance measuring plastic thread (automatic translation by Shopify)
Almost every four-stroke engine manufacturer's manual contains a reference to this clearance measuring device, which is extremely easy to use. This " Workshop tool " is nothing more than a very thin and soft plastic thread, which can be used to determine the operating clearance of plain bearings in the engine in a few seconds. must be installed, the screws must be tightened with the specified torque, but a piece of Plastigauge must be placed in the gap as shown in the picture. The plastic thread flattens in the gap and after repeated disassembly, the size of the bearing gap can be directly read from the attached scale. It is very important during disassembly, to move the component parts away from each other in such a way that they do not accidentally move them laterally in relation to each other, as this will smear the flattened fiber and fail the measurement.
There are 10 measuring threads in one package, one thread is sufficient for checking the main bearings and crank bearings of a four-cylinder in-line engine. The measuring thread is soft, cannot damage the parts in any way, and can be wiped off the surfaces after use.
In addition to measuring the bearing gap, the Plastigauge is also suitable for checking the flatness of the cylinder head and the deformation of cylindrical mating surfaces (flushes). The theoretical accuracy of the method is one thousandth of a millimeter!