suprfast

okay we hear all this hype about the 3 rotor but one thing keeps bothering me, how long will it last. im not saying that im getting one but like i said, its just something that is in my mind as i read people doing this. if it is just another rotary motor(how can we call the 3 rotor just another...) wouldnt it last just as long as our two rotors??? im talking turbo models though, not the older NA that last forever. is it worth that much for something that will hopefully last 100K miles??? well after all the install in complete it would be like tossing a stocker in once it goes. sorry to be so negative. dont get me wrong, if i had the money i would do one. all motor though, now that would be fun.
kris

rx7even

Basically if you run a 3 rotor at say 10 lbs of boost, it will last as long as a 2 rotor running 10 lbs of boost. The only "real" difference between the two is the 3 rotor has a different eccentric shaft and one more rotor and housing (and side housing for that matter). Plus, at 10 lbs of boost, the 3 rotor will be making a lot more horsepower and torque then the 2 rotor running the same boost. Obviously there's more to it than that, that's just sort of the edited/summary version.

RETed

The 20B should last longer, period.&nbsp The additional front/center housing bearing adds strength and support to the longer eccentric shaft, and it helps minimize flexing and resonance of the eccentric shaft at higher RPM's.



-Ted

now

iTrader: (1)

I agree with reted on this one, but for a different reason,
the 20b really has no more bearing area than the 13b
for the 2 rear two rotors ,so the issue of
bearing area helping is not the full story.
I would say the 3 rotor will last longer because, it will
get the same power as a 2 rotor, but will have to work
that much less to do it,
also the 20b work per rotor per shaft rev. is less
because of the rotor timing across the 3.
kind of hard to visualize but that's how I see it.

matt