Learn Me: 1st Gen WRX (JDM) Engine/Trans

Hey Guys,

What can you tell me about early WRX engines and transmissions (and Subaru parts compatibility in general)? I'm thinking about picking up an imported JDM WRX drivetrain, looks to be from '93, and have a bunch of questions. I've looked on NASIOC and didn't find much useful info. Here's what I'd like to know:

1. How does the transmission compare to other USDM units from the time? Is this basically the same thing as an early Outback 2.5 transmission in terms of strength? Do USDM axles/driveshafts and clutch assemblies fit?
2. Is the engine as robust as newer (EJ205) engines? This one is an open deck.
3. What about rebuild kits for the engine, is there a USDM engine that uses the same headgaskets/bearings?
4. Do manifolds from 2.2 or 2.5L NA engines swap over to this engine?

Interested in hearing any input you guys have. Thanks!

a lot of little differences. Ecu, wiring and sensors are different. You may be able to replace some with usdm equivalents, but don't count on it. There are several(7 or 8) versions of the 2.0 turbo in early wrx's so it's not something you can't make blanket statements about them and compatibility. Some jdm motors with not work with a left hand drive setup, due to their turbo placement.

There is a fair amount of info on nasioc in the hybrid drivetrain forum in the stickies, you can also look on wikipedia for the subaru EJ engines for more detail.

If the engine/transmission are from a 93 I think that makes it an EJ20g.

I am going off my grey hair addled memory so I could be wrong. The crank is phase 1 so a later phase 2 (98+?) will not swap directly in because of the location of the thrust bearing. The coils suck bad and MUST be replaced/upgraded to newer ones off an 02+ wrx. The ecu is the old Denso 76 pin. The headgaskets of other phase 1s wont interchange. The rods are the same but the pistons are different. The water pump will work if you have the heat exchanger but I think that depends on the option package that was on the car. Transmission is basically same as newer 5mt but has different ratios and a push clutch. You can get the right JDM parts without too much trouble or you can mix and match parts from USDM cars (mostly 93-96 Legacys) to get pretty much anything you need for this engine.

I think that the big thing to remember is that it might be a low price but you are buying a 20 year old used motor from overseas so any deal you get better be worth it to cover any reconditioning it will need.