Yeah, it would, assuming the time release does it's job evenly. However, 400 mg of oxycodone is an awful lot. You would be getting 50mg every hour they are in your system. The body can not process them out as fast as your talking about putting them in. So towards the end of that there would be a greater concentration in your system than when you began. Also, if it's too much for you -- the time release would continue to make you ill for hours and hours and hours on end. In all honesty, that's way too much to be taking IMO. People have gotten serious ill, even died, from doses far less than that.
If you did have a problem on it, they would have to give you narcan several times to try to bring you out of it. That's not a pretty scenario. I wouldn't reccommend it.