Oil leak problem

I recently filled up my 88 Supra motor oil to the max. However, I have to pour in a bottle every 2 weeks. I don't see a leak when the car is park or smell the burning of oil while driving? What seems to be the problem?

Well if its not burning then it's got to be going somewhere, have you taken off the underbody panel yet? I'd bet its covered with oil. Also pop off the plug wires cause I'd imadgine the valley could be full too.