A couple of tid bits about
oil coolers that you need to know.
Oil is heated by RPM's. Routine or even hard steet/highway will warm the
oil to about the same temp as the coolant, and maybe a little higher. But not that much higher. If the coolant temp is a steady 180*, oil temp shouldn't get more than 200*'ish.
Oil has an operating range. Max temp depends on the oil type, and duration. Sometimes a higher oil temp will result in a litle more available power.
Minimum temps is a bit tougher to obtain, but seems to be about 180*. Below 180*'ish, the oil and the additive package don't work they way they're supposed to. For example, a 10W-40 oil will have the viscosity of a 40wt oil when heated to 100*C. What is the viscosity at 60*C? IDK.
There is a myth that if the oil doesn't get above 100*C, the water that collects in the oil will remain there. That's rediculous. If that were true, your kitchen floor would never dry.
So, the trick, then, to use an oil cooler, but not actually cool the oil. Most automatic thermostats - Mocal, Russell, Canton - are never fully closed or open. When cold, about 10% of the oil is routed through the cooler. That allows all the oil to warm up at the same time. When fully open, about 10% is routed directly back to the engine, and that prevents pressure drop and starvation. Unfortunatly, on a cold day your oil will still not get warm enough, even with the cooler cover with cardboard and tape. I know, I'v tried it.
As I understand it, the Beaumont valve will actually allow you to completly shut off flow to the cooler. That's what you need - the ability to completly stop the flow through the cooler. The Beaumont valve is pretty nice, and looks great. But, you could accomplish the same function with two $15 ball valves and a handfull of AN fittings.