Rotary Alx

Yes as the topic says ,

Any "special" pointers , beside the essential ones .

Such as : the twin dizzy rotor housing surface , is maybe best suited to the light 6mm OEM "carbon "apex seals , how will the surface work with , say , OEM s3 rx-7 12a seals / atkins etc etc , steel ones , increased wear ,

: Weight difference , counterweight - flywheel . Use the front & rear counterweight matching the new rotors , and / or matching flywheel .

: Stat gear upgrade to newer / matching type rotors used

: Asymetrical combustion "chambers" differences on newer rotors , FRONT / REAR rotor .

: Placing of intake ports , regarding former dual sideseals , now single sideseal .

If anyone should have som input , pls share .

Thanks .

trochoid

iTrader: (6)

Iirc, the older housings wore much quicker than the newer ones. This was due to the difference in the surface coating/treatment. As long as you match the rotors, front counterweight and flywheel, you shouldn't have any problems using the S3 rotating assembly in the early twin dizzy engine. If you want to reduce housing wear and preserve the older housings, you can use 3 mm carbon seals. They do not seal as well, particularly at lower rpms, as the newer steel ones do and will wear out sooner. Another option is going with ceramic seals, but they are pricey, over 1k/set, and may wear out the older housings quicker than they do with the newer ones. Fwiw, carbon seals are dirt cheap but will break easily due to detonation. Not usually a problem on NA engines, a big nono on turbo/supercharged engines.

As far as upgrading the stat gears and the asymmetrical combustion chambers, no problem there. In fact, hardened stat gears with 3 window bearings and carbon apex seals are recommended for engines that frequently see 8k+ rpms. If you plan on running 8.5k+, balancing the rotating assembly is strongly recommended.

Rotary Alx

Hey ,

Thanks for the input trochoid , regarding the carbons , im very very happy with my 12a full bridge , on carbons , great start up both cold and warm , and appears to seal totally okay even at low rpm`s .

This motor " the twin dizz 12a " is goin in a all stock rx-2 , so no power upgrades , only reason for changing to newer rotors is that parts actually are available , not having to search the whole planet to find an old man i a barn thats got som used 6mm parts to sell .

yo yo .

Regards Alex