I just purchased a few crankcases from BME that will be used to make small twin engines using Echo weedwhacker engines. The parts that I received from BME are a nice anodized blue and the machining is very good. I am starting to get together the parts that I need to make an engine, it looks like I will have to use the 21.2 pistons and cylinders since I haven't had any luck in finding the 23.6 engines, if anyone has the 23.6 cylinders and pistons I would be interested in making a purchase. I started this thread hoping that there would be some other RCU members starting the same project and we could share information.