There really is something to be said about looking at a good map so you can see for yourself what you are looking at. As much as we try to help, a map will always be able to paint a much better picture than words, and it really seems like you are missing that picture.

GLC already mentioned that it would be about 8 hours of driving from Lake Isabella to Yosemite, via Sequoia. Both Oakhurst and Yosemite Bug will put you about an hour from the Yosemite Valley, although coming from different entrances into the park - keeping in mind that you'll get to the start of the National Park about 30 minutes before you are in the Valley itself.