The question in one of the threads came up about the amount of torque a 4 rotor crank shaft must endure?
Does anyone know?
Of couse the shaft would be weaker than the 3 rotor and 2 rotor. What did Mazda do to beef this up with the 787b? What about the guy in NZ cutting the special billet shafts. Is he doing the same thing Mazda is?

 

I will bet on the 787 they streangthened it somehow. I wonder if tehy did not have speacial ribs cast into it or something. not sure but i would kinda like to know. not sure anybody realy knows about the 787 though. not many have seen the inside. hehaaa.

cjg

 

don't forget the 787 is a non-turbo, it "only" makes eeh ~700 hp? something like that, i'm not sure. and you can reach that hp with a stock shaft. the only problem could be high rpm
my 2 euro-cents

 

The 787B engine wasn't that high of rpm, if memory serves me corretly they set the redline @ 8,000rpm for qualifying and 7,000rpm for the 24hr race. If you apply the hp formula (hp=torque * rpm / 5252) you can see the 787B 4 rotor developed 450-550ft/lbs. I would guess they reduced the stress on the shaft by placing a bearing in the middle, since shaft flex can cause the rotors to come into contact with the housing and a 4 rotor shaft is awful long.