how long after the coolant reaches its optimum temperature, does the oil reach its normal temp? in other words, how can you be sure when its safe to hit the high rpms?

 

I add the amount of time it took to get up to coolant temp
for example if it took 10 minutes to warm up water.. wait 10 more for oil to hit..
best is to get an oil temp and pressure gauge..
or a pressure guage..
when your pressure drops from 75 to 12.5 on idle.. and 50 at 3000 RPMS oil temp is where it should be

when it's cold.. it'll be around 75 until it warms up

 

I would think it pretty much depends on the viscosity rating of the oil you are using. If your engine coolant temp is in the normal range, I would think the oil is warm enough to lubricate the engine sufficiently if you are using the recommended viscosity. It all depends on your definition of 'high rpms' though.