Big Bore Displacement Question

[dquarton]

I recently purchased a really nice 400EX that is built to the max pretty much and the owner claims the engine is 472cc. He was sure that was the displacement (so he says) Problem is he bought it from the guy that had all the work done, so naturally he does not know what was done to achieve 472cc. Is it possible to achieve 472cc without a stroker?? Would a 5mm stroker achieve the 472cc??

Thanks!!

[Zakradu398]

Stock cylinder 87mm bore and 75mm stroke (+5 stroker crank) would be 445 ccs.
A 7mm stroker crank and 87mm bore would be 456cc.
A 7mm stroker crank and a 88mm bore would be 468cc.

[dquarton]

Originally posted by Zakradu398
Stock cylinder 87mm bore and 75mm stroke (+5 stroker crank) would be 445 ccs.
A 7mm stroker crank and 87mm bore would be 456cc.
A 7mm stroker crank and a 88mm bore would be 468cc.

OK, great info, thank you!

[Zakradu398]

Stock bore is 85mm and 70mm stroke by the way.