I was looking at a 20b online that has a broken rear plate (piece that bolts to trans). Is that rear plate interchangeable with a 13b rear plate? I intend on tearing it down anyway and rebuilding, let me know

 

Cosmo RE 13B rear Iron is the same

 

the cosmo 13b is identical, but any rear plate will change out.. its just that some plates are thicker than others. if its NA then it wont matter at all, but if its turbo, then go for a REW or RE plate.

 

So your saying the Cosmo Re plate is already machined to fit some of the 20b's larger tension bolts?

 

scratch what i said, i guess i wasn't aware of the whole larger tension bolt thing.

but in this case, you could make any rear plate work.

 

Yes, minor machince work required.. open up two holes to 12mm.. Simple...

 

throw a plate on it from the engine that was originally in your car. mounting will be easy peasy.

 

Engine mounts differ..

 

you have to machine a couple of tension bolt holes larger also DO NOT forget to countersink them or you will crack the plate when you try to put it together. You also have to drill and tap the bottom of the plate for oil pan bolts, and drill and tap a hole for the 20B engine mount bolt.

20B ports are also bigger, so a lot of grinding is required.

That said, I am running a REW rear iron and am perfectly happy with it.

 

Could one not mount the engine with the 13Brew plate onto a stock FD subframe with 13B engine mounts... I`m sure this has been covered before but since were on the topic...

 

Im actually looking at that very same motor with the damaged rear plate.

http://mazdatrix.com/getprice.asp?partnum=10-C50D-NF01

Just get you a new plate and mount it. Easy peasy and nearly $1k cheaper than buying a normal 20B

 

The engine in question is a B-series, for what it's worth.

 

i wonder why the rear plate is broken..

 

link to the 3 rotor

 

not unless one wanted to make a custom oil pan, and it still wouldn't put the engine in the right place