kabooski

there's a company in canada that makes upto 6mm apex seals!

you all machine your 2mm rotors for 3mm
Just machine it for 6mm
LoL




http://www.rotaryengine.ca/apex.htm

HWO

the stock 3 piece 2mm seals will handle over 1200HP worth of strain in a 2 rotor, why on earth would you be wanting anything larger? - to make up for poor tuning ?

Wankawankel - the name says it all, sure you aint a diehard pushrod v8 fan in disguise? cause your comments are the same. gotta wonder how much of a true rotary fan you are..............

Maxthe7man

The earliest of rotary engines used 5mm apex I do believe, arent they the ones though that had the infamous "seal" problem that gave the mazda a bad rap early on? If you talk to any old car guy from the 60's and 70's about rotary engines, they always say, "those things were oil burning pieces of crap, they had a problem with the seals".... I would think larger seals would introduce more inertia load to the seal springs, which would hurt sealing, Mazda has gone thinner and thinner on the seals over the years, obviously they have discovered something with that besides cost savings on materials..
My car has 3mm apex seals, I have often thought about buying new rotors to get back to 2mm seals, everytime I think about my motor, the warning from the RB book rings through my mind about not machining the rotors to get 3mm seals, when it dies I will most likely go back to 2mm's though..Max

peejay

The original 5mm seals (I've heard both 5mm and 6mm for the pre-74 engines) were carbon-aluminum so they weren't very heavy. Lasted about as long as you'd expect a carbon-aluminum to last. They also had lots of *water* seal problems that they fixed for '74. (Well of course they burn oil, they inject the stuff... )

My only beef/regret is that Mazda never made 2mm 3pc seals and rotors for the 12A. If you want the good stuff you have to get a 13B. *sigh* To get high revs from a 12A means you need carbon-aluminum seals and a rebuild every winter.