Scraped old site and uploaded new site,

whats the approximate time it takes for google to index a site and update it is it every few weeks since my site isn't that popular?

Old pages/content still being indexed, so i created a custom404 page incase someone visits by error, although the site is so far back i doubt it

if you have done seo well before the google should come in 4 days once ,
They will start loking into the links from page also.