It would have come in two thrust ratings, 104,000 lbf (460 kN) and 114,000 lbf (510 kN), and has been tested up to 117,000 lbf (520 kN). As Boeing's thrust requirements increased, Rolls-Royce began developing the 115,000 lbf (510 kN) 8115 which was to be an enlarged version of the 8104, with a m (120 in) fan and a core scaled up percent from the 8104. It featured swept-back fan blades and a host of new technologies such as contra-rotating spools. The 8115 was never built, as Boeing signed a contract with General Electric to be the sole supplier of engines for the 777X aircraft, owing to GEs willingness to risk-share on the airframe part of the project, and sales of the aircraft to GECAS .
The Trent 1000 family makes extensive use of technology derived from the Trent 8104 demonstrator. In order to fulfill Boeing's requirement for a "more-electric" engine, the Trent 1000 is a bleedless design, with power take-off from the intermediate-pressure (IP) spool instead of the high-pressure (HP) spool found in other members of the Trent family. A m (110 in) diameter swept-back fan, with a smaller diameter hub to help maximize airflow, was specified. The bypass ratio has been increased over previous variants by suitable adjustments to the core flow.