hydraulic pump/ motor question

Question: I am building a 25 hp steam engine with a shaft RPM of 100. As with all steam engines rpm's are low and rpm's need to be increased to run generators, saw blades etc. Normally they are raised by large flywheel type pulleys, large on the output and small on the generator via wide leather or rubber belt. I want to use a hydraulic pump running at 100 rpm and power a hydraulic motor at 800 rpm. Can this be done. I realize there is a considerable power/torque loss with increasing speed which would occur using chain, belt, or gear box methods anyway. I will need about 15 hp @ 800 rpm.