At Cat in the late 80's we had JWAC (engine jacket water aftercooled) engines, and SCAC (separate circuit after cooled) engines. The EJW type were only rated at 85% of the BMEP of the SCAC.
Highest rated of all were the AAAC (air to air aftercooled)
Interestingly, Cat offered the JWAC and SCAC versions only in 8.5:1 compression, and the AAAC in 10:1. Wastegates were set to 15 PSI.
These were all natural gas fueled engines (>90% methane) so the octane was normally at least 105, and sometimes 110 or better.
John