I come up with 211 pounds based on 181 pennies per pound using 1982-2008 pennies.
Are you sure you didn't make a decimal point error? Wikepedia reports each penny weighs .8818 OZ. I just multiplied then divided by 16 to get the answer.
I'll check it again and find a different source for the weight of a penny.
edit:
I found this:
The first pennies were made in 1793 and were 100 percent copper. From 1857 to 1864, they were 88 percent copper and 12 percent nickel. From 1864 to 1942 they were 94 percent copper and 6 percent tin and zinc. All of these early pennies weighed 3.1 grams.
In 1943, pennies were made of steel coated with zinc and they weighed 2.7 grams. From 1944 to 1981, pennies were 95 percent copper and 5 percent zinc, weighing in at 3.1 grams. From 1982 to present, pennies are now 97.6 percent zinc and 2.4 percent copper and weigh 2.5 grams.
There were a few variations after 1944 between the amount of amount of zinc and copper, but not enough to mention. In summary, pennies weighed 3.1 grams from 1793 to 1981, except for the year 1943, when they weighed 2.7 grams.
so the minimum is 2.7 grams, the max is 3.1 grams....now off to do the arithmetic....be back in a minute
edit 2: minimum is 234.5 b. max is 262.4 lb.
So you are right. The weight of a penny that I used in my original calculation was incorrect.