Honda Acura NSX 1991 Service Manual page 411

Oil Pump
The external tooth gear type oil pump consists of a housing together with the main valve body, a pump drive gear, a
pump driven gear, and a pump shaft. The oil pump is installed on the torque converter housing. The pump's driving force
is transmitted by the torque converter pump (directly connected to the engine) to the pump shaft. The gears are provided
in the housing. The intake and exhaust lines and the torque converter line are provided in the housing.
One way Relief Valve
The one-way relief valve is used at times of high speed or high temperature to send relief oil to the oil cooler so that
cooling of ATF will be effective.