How long will this take to cook?

I’m planning on cooking this 8 pound butt for carnitas tomorrow. Chunks are in the 3-4 inch range. I’ll start out letting it smoke/simmer in it’s own juices for a while, then add some water-based liquid (OJ and water mostly), and braise it until the liquid evaporates and the meat crisps up some on the outside. I can add more liquid if the meat isn’t done by the time the water evaporates.

I’ll be doing this on the WSM 22.5 at 275 F, or maybe closer to 300 F if I can get her to cooperate with me. How long do you think this will take? I’m guessing 4 – 5 hours, but not really sure as I haven’t tried anything like this before.

Yes, I'll be juicing a couple of oranges and throwing the spent oranges in. Also probably will zest them first and use that in the rub.

I started it out in one pan because I already had another whole butt on the grate, which I didn’t want to have to pull to put in the lower grate. I ran just the meat in the pan for about an hour and a half, then added my two cups of liquid (OJ, lime juice, and water), which turned out to be way too much. After the meat gave up its liquid, the pan was full nearly to the rim. After the whole butt finished, I moved half the meat and liquid to a second pan. The meat was done after about 5 ½ hours total, but the liquid was nowhere near reduced, so I reduced it on the stove top and finished crisping up the meat on the gasser. Then drizzled some of the reduced orangey glaze (which I had to mine from underneath about 3 inches of fat) on the shredded meat.

All in all, it was pretty good, but not as flavorful as I wanted it to be. I doubt I will try this method again. I was trying to do something close to traditional carnitas, but I don’t think it translates well to the smoker. Next time I’ll probably leave the butt whole, rub it generously with salt, pepper, cumin, oregano, garlic powder, and orange zest, inject with OJ, then cook it the normal way on the grate. I’m guessing that will produce better flavor.

Thanks much, everyone.