Thank you both for you quick response, I appreciate it. I am familiar with most of the 3D portals, but sometimes I look for something and the easiest way is just to draw it, sketch it and then look for the similar parts/models. Sometimes I need functionality, too. This is why I was wondering is there any other 3D search engine based on that. The only one I have found is that one I mentioned in my post - 3DfindIT.com
Once again, thank you for your help!