Bone-in pork roasts range in size from 2 lbs. to 6 lbs. and require a cooking time of about 20 minutes per pound at 350 degrees Fahrenheit. Do you cover a bone-in pork roast? The bones act as the roasting rack. Loosely cover. Continue checking the temperature every 15 minutes until the internal temperature reaches 140 degrees.
As a general rule of thumb, you want to cook the boneless pork loin roast at 350° F for about 20 minutes per pound. In this case, a 4-lb. roast needs about 1 hour, 20 minutes in the oven. What temperature do you cook a 3 pound pork loin?
ROASTING: Set oven at 350° F. Roast in a shallow pan, uncovered. Internal temperature: 160° - medium; 170° - well done. BRAISING: Cover and simmer with a liquid. STEWING: Cover pan; simmer, covered with liquid. USDA Revises Recommended Cooking Temperature for Pork to 145 °F! Finally, Pork Doesn't Have To Be As Tough As Leather.
Bone-in pork roasts cook more quickly than boneless roasts because the bone helps conduct heat to the center of the meat.