Don't worry, it's not the beer you're thinking of, rest assured the Orange teenagers won't be glugging down schooners before or after their enduro races at Sydney Motorsport Park.

"It's Angus Beer, he's racing so we may as well all give up," Tom joked, speaking of Newington College's multiple-time national champion who's on the verge of college scholarships in the US.

"He's in our age group and he's won national championships and Oceania championships too, he's a bit of a freak really," Thornhill added.

Joking aside, Thornhill and Tom are champing at the bit to come up against the likes of Beer at the Eastern Creek course, they'll compete for in the 6000-metre, 17 and 16 years boys' races respectively.

"It's good to be able to run in events against athletes of that calibre," Thornhill said.

"At this age you get runners like that who are devoted and go through 100-kilometre (training) weeks, whereas we all split our attention between different sports, like triathlon for me and swimming for Elliot."

Will Thornhill and Percy will both be tackling the 4000-metre 15 years boys' races, the quartet all earning their NSWCCC spots after a gruelling selection process that spanned school, Diocese and then state-based races.

It's a big achievement for all four of the James Sheahan students, and Will Thornhill, Percy and Tom all admitted to being shocked they'd earned their state gigs.

"I was near the back of the pack (during the NSWCCC trials) and felt like I had a bit of energy so I kept going, I thought I might have been about 20th but I found out I was 10th and was just like 'what?'," Percy explained, with Thornhill saying the same after finishing eighth.

"I was the same, I didn't know until I saw the results," Tom said.

There's NSW All Schools spots on the line at Friday's championships too, the top six finishers from each age group will earn a crack at the national championships.

Being competitive young men the quarter all agreed being able to run at the Australian titles would be an incredible experience but they're staying grounded in their goals.

"I'd love a top 10 finish, that'd get me a reserve spot for nationals," Rory Thornhill said.

"I'd like top 50, but I'd have to shave about 40 seconds off my time to do that," Tom added.

"Rian and I just scraped into the CCC team so we're just happy to be here really, we'll go and run, do our best and see what happens," Will Thornhill explained.

"Yeah, we'll just go and do our best and see what happens," Percy said.

The NSW All Schools Cross Country Championships start at 9.10am, with staggered starts across all the girls' and boys' age groups, at Sydney Motorsport Park.