Wow, you are pretty mad to solo mine with just that set. even it finds a block every 77 months it won't be profitable at all, or it will only be profitable if the bitcoin prices goes up to the double.
How did you calculate approxx block finding period?
There are plenty of online calculators that provide you with this information. If you'd like to calculate it yourself, a good formula to use is:
Current Diff * 2^32 / hash rate / 86400 = time to solve a block in days
So, if we use an Antminer S7 as an example (4.75T):
194254820283.44 * 2^32 / 4750000000000 / 86400 = 2032.94
Yup, the S7 expects to take just over five and a half years to find a block at the current difficulty.