Diesel engine power

hooligan wrote:

Crespro wrote:

The torque/HP question arises periodically. My question is: do all of these engines produce rated torque at the typical 1,600 RPM? What is the difference in the torque/RPM curves?

Torque and rpm values vary greatly even among the same engines. My ISB 260 produces 550 ftlbs torque at 1900rpm while another version of that same engine is available with 260HP, 660Ftlbs at 1600rpm.

ISB Engine ratings

I notice in the ISB chart posted that the ISB 225 has 225hp and 605 ft lbs @ 1600 rpm and the ISB 225 has 225 hp and 520 ft lbs @ 1600 rpm. How can these engs have the same HP and different torque values at the same rpm? Is this a typo or am I not understanding something more basic.