Time to start flipping! Need a private lender!

[Walter Ocampo]

Currently I have three properties. A one bedroom one bathroom home, a triplex (my family and I live in one unit), and a quad. The one bedroom is paid off, we have a HELOC on the triplex, and a mortgage on the quad. I hit the debt to income wall and was denied on increasing my HELOC. Now, I'm thinking about acquiring some private money so I can add-on to the single house making it larger, and flipping it so I can acquire more cash to invest in more units. The house right now is worth about $150,000 and new 3br/2ba homes in the area are selling in the $450k - $500k range. This would allow us to pay off a private lender and still have a good amount of cash that we can reinvest. Any advice is welcomed!