The two significant challenges on the RB30 relate into the oiling process and crank collar. This isn’t certain to only the RB30 series, as the RB20/25/26 even have pointed out issues Together with the oil pump and oiling techniques. All of them are afflicted by this difficulty (early RB26 only). https://martinjitxb.life3dblog.com/27706336/rb26-engine-for-sale-an-overview