The phrase "a shitload of time" is correct and usable in written English, though it is informal and somewhat vulgar.
You can use it in casual contexts to emphasize a large amount of time spent on something.
Example: "I spent a shitload of time trying to fix that old car."
Alternatives: "a ton of time" or "a large amount of time".
He said he "got many a legal nastygram from firms representing the actresses, spent a shitload of time on the phone to lawyers" and spent tens of thousands of dollars in legal bills.
Your average DIY park probably cost a shitload of time and money, but it has no market value.
It's a very good video game carefully crafted into its final, many-fans-satisfying form by a team that has quite clearly devoted a shitload of time and care to the process.
Below, you'll find reviews of (mostly) Syrian music, written by Syrian Americans, or in the case of Shalib Danyals, a person who has spent a shitload of time in the country.
First of all, security doesn't save time even if you think that our security theater really saves lives, it clearly takes a shitload of time on everyone's part to travel through the massive security line, get scanned and/or frisked, and have your bags opened.
'Cause the alter-ego you created and have been nurturing for the past fifteen years or so is now facing a 78-page federal indictment -- and probably a shitload of jail time.
Alongside other breaking news, the Josephson Institute has wasted a shitload of its time and doubtless a hefty wodge of money finding out some simply stunning things about kids in America.
I know that it's not always realistic not to be stressed when you're spending a shitload of money and time planning one day, but if you just breathe, and remember that you CAN do this, your inner rockstar will shine through.
What I was thinking was, that's a shitload of one-on-one time with myself and focus on me.
He'd made a "shitload of money" but had never had time to spend it.
