WOW... 1.7GALLONS / Minute! That is an enormous amount of flow!
In a Walboro 255 Litre/Hour fuel pump there is a lot of flow, but in comparison:
There is 3.8L in a gallon, so...
1.7 x 3.8 = 6.46
6.46 x 60 (mins in an hour) = 387.6Litres/Hour!!!
To be honest, that much flow in cooler that would just keep circulating the oil through the pan which is somewhat of an isolated location because the rate of circulation would be faster than the circulation through the motor's oil system, therefore it would be cooling the oil faster than it could heat up causing it to be cooled too drastically! Unless of course a switch/thermostat was routed in line... then this would be a very quick and effective oil cooling system!
But, completely unnecessarily rapid. Flow rates at half of that magnitude or even less would be sufficient!