WFFMM-NAAM Conference 2022

Functional conservation, i.e. keeping mechanisms in working conditions, is, from different points of view, the best option to allow visitors to fully enjoy the experience of historical vehicles collections. Nevertheless, this choice has many advantages but does not come without risks. This is the reason why many institutions worldwide have different methods to restart engines. Acoustic emission (AE) may determine the condition of the engine before deciding if it could be restarted or not. The use of AE techniques for historical engines was implemented during the Acoustic Emission Monitoring of Historical Vehicles (ACUME_HV) research project that the Haute Ecole Arc Conservation-restoration has carried out in partnership with the National Car Museum of Mulhouse (MNA), France, (Schlumpf Collection), that has, since many years, a policy of running or restarting engines and the Polytechnic of Lausanne. During the first phase of the project, the AE technique was applied on three similar engines to compare the results. The first engine was a two-cylinder Renault AG1 without heritage status mounted on a bench test to determine a measurement protocol and simulate breakdowns. The second engine was from a heritage car from the MNA collection (Inv.2209), on which the repeatability of these tests was also verified. The tests verified the condition of the engine and even identified a breakdown that was not detected with routine monitoring. Finally, other tests were performed on another engine (Inv.7003), which was supposed to be in a bad condition, to represent the “worst case.” The acoustic emission measurements reinforce the need for maintenance tracking reports. However, the AE technique is very complex and sensitive, so more research work is ongoing to obtain a more complete understanding of the results.