Ottoman

i've got a REW shortblock

and a full cosmo swap..

but the cosmo as a blown rear rotor (i think it chewed it up pretty bad) but the front rotor has Awesome compression... so it would be a pity for it to goto waste.


are the parts between the 2 blocks interchangable? or is there some differences?

does it matter if i use the REW's front housing or rotor on the back of the RE?

GUITARJUNKIE28

there are differences in the mounting of the engines.

look at your rew block. the rear iron is tapped for the motor mount bolts. the mounts are on the sides of the cosmo. i'd just rebuild that one iiwy.

Ottoman

thanks guitar..

so the irons are diff... fine..

but what about the Housings?

onefastrx7turbo

iTrader: (5)

all 13b housings are interchangeable. the rotors between 13BRE, 13BREW, S5 turbo, and 20BREW are all same. the s5 rotors machining is different but the comp ratio and the weight are identical. also, look at the runners of the RE vs the REW. the RE's are HUGE compared to them., rebuild the RE and slap it in there

Ottoman

good stuff...

so all i gotta do is open the stack

toss the old Rear Rotor and Rear housing

rebuild the lot

stick the REW rotor and housing

and close it up?

onefastrx7turbo

iTrader: (5)

might want to make sure the 13bre doesnt have the exhaust diffuser in it like the 20b's do.

Ottoman

already removed the turbo's and checked...

no diffusers.. i can stick my hand in and pet the apex seals all day long

little mark

so the two motors are exactly the same other then the mounting areas?

GUITARJUNKIE28

the ports are different.

re's have larger runners. same secondaries, but the primaries are smaller and open later. i can only assume this is for a cleaner charge in the low end and more torque--since that engine came in a big, heavy car. think velocity porting.

the "ultimate" flow engine as far as that's concerned, is the re irons, either ported/sleeveless, or t2/fd rotor housings, re intake, and fd throttle body. i did one engine like that and put down over 400whp on an s4 hybrid turbo with a VERY conservative tune.

the thing i like about cosmos and renny's is the motor mounts don't go through the oil pan. i don't know what mazda was thinking on the fc and fd motors, but that's just an oil leak waiting to happen.