Root said England were "completely different" from the team thrashed 5-0 on their last visit and should dwell on their Ashes victory on home soil in 2015.
"There's been a lot of talk about last time around (in Australia)," Root told reporters. "We were a completely different side, and so were they (Australia).
"Of course, they will try to bring up all sorts of stuff like that. We've played a lot of cricket since then, and we've played against Australia since then as well -- and that went quite well for us.
Australian players have been keen to talk up England's struggles in 2013, when they were terrorised by the Mitchell Johnson-led pace attack.
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England's inexperienced batting line-up has been highlighted as its biggest weakness as it aims to emulate then feat of Andrew Strauss' team of 2010-11 by becoming only the second England side to retain the Ashes urn in Australia in 31 years.
England also look likely to be missing star allrounder Ben Stokes, who is suspended pending investigations into a nightclub brawl.
"Whenever you play any Australian opponent you don't expect an easy ride," said Root.
He said the tourists need to make the most of the momentum swings that go their way during the five-Test series, which gets underway in Brisbane from November 23.
"We are going to have to play well as a side, show a lot of character as a group and there can't be any selfish mentality out in the middle," he said.
"It's going to have to be about doing your job within the team, and not worrying about individual performances.
Root said England will field 13 players in the opening two-day tour match with Steven Finn, Moeen Ali and reserve wicketkeeper Ben Foakes to miss out.
"We'll play the same top six batsmen if we can. You want continuity in the top order," he said.
"But you never know what can happen in these warm-up games. Somebody might get injured."
Root added that he expects team management to name Stokes' replacement as vice-captain within the next week.
Paceman Finn (jarred left knee) and allrounder Ali (side strain) are sidelined from the opening game.
England: Joe Root (capt), James Anderson, Jonny Bairstow, Jake Ball, Gary Ballance, Stuart Broad, Alastair Cook, Mason Crane, Dawid Malan, Craig Overton, Mark Stoneman, James Vince, Chris Woakes.
WA XI: Nathan Coulter-Nile (capt), Will Bosisto, Jake Carder, Tim David, Kyle Gardiner, Aaron Hardie, Clint Hinchliffe, Nick Hobson, Calum How, Lance Morris, Josh Philippe, Mark Turner.