Material for Moto Guzzi main bearing

[Graeme.A]

How would I find out what material is used for the main bearings (pressed into the carrier) in a Moto Guzzi motorcycle? seen here

https://moto-renzo.biz/images/product_images/popup_images/MG_lager_kw_hi_3848_0_3849_0.jpg

http://www.thisoldtractor.com/moto_...hive_engine_crankshaft_and_main_bearings.html

The crankshaft is about 6kg and the bearing journals are 54mm and 37mm diameter. The bearing length is 40mm. It is some type of Al alloy that has been manufactured in Italy since 1967.

 

[EngineerTex]

Do you have the original, presumably failed, bearing? If so, have XRF (X-ray fluorescence) done on it. If you prepare the sample, sand it with SiC and remove all traces of anything that could have been deposited by the crankshaft, as that will give you a false reading.

Engineering is not the science behind building. It is the science behind not building.