EJ20 block w/ EJ25d heads?!?!?

[Doaomo]

http://www.rs25.com/forums/f171/t195287 ... za-rs.html

Soooooo, I just got the car linked above this past saturday. It needs a tune and it's overheating with bubbles coming up in the rad. I started trying to find other ej20 block/ej25 head builds and can't find much. What I have found said it does not work out so great. I'm not experienced with this so a good conversation here with people who know hybrid turbo build will be invaluable to me!!!

[mike-tracy]

There are several ej25d heads out there. In the states we got two: the 1996 engine with HLA's and an ej25 sized combustion chamber, and the 97-99 ej25d with 2.0L CC size and shim over bucket valvetrain.

The 96 heads are related to the 92-96 WRX ej20g heads, and are very similar except for CC size and cams (and of course not pliumbed for a turbo). The 97-99 us heads are very close to ej20k wrx heads, except for plumbing and cams.

In my opinion the later style heads would be great on a 2.0. Throw some turbo cams in there and they'd be even better.

[Doaomo]

Hey thanks Mike! Are there any identifying marks on the 97-99 heads I can look for?

[mike-tracy]

Valvecovers are smooth on 97+, 96 says "16 Valve" on them. Compression ratio should be very similar to stock. What short block is in there?

[Doaomo]

I was told the short block is from a 05 wrx. So a ej20g??

[James614]

EJ205. The EJ20G was 92-95 WRX.

[Doaomo]

Thank you, I've only had first gen tleg up till this weekend....

[Doaomo]

How do I identify what kind of ej20 block is in there? I only know how to identify ej22t's lol.

[mike-tracy]

99.999% sure it is open deck.

[James614]

I would search on NASIOC about identifying short blocks. Although the EJ205 is the only EJ20 offered in the states, so its pretty unlikely its something else.

[bmxkelowna]

Do we know what the compression ratio would be with a jdm legacy ej20g block and late ej25d heads?

[mike-tracy]

It would be a 10th lower than a stock ej20k. However, on dirtyolbc.co.nz they told me stock legacy pistons would hit the valves of 20k/25d heads.

[bmxkelowna]

Actually?? The legacy ej20gn pistons are that different then the wrx ej20g pistons?

[mike-tracy]

Yes, they have radically different pistons and heads. Honestly, I am rehashing info I heard on another site. I think it'd be worth your time to do some digging on rslibertyclub or dirtyolbc, since they have first hand information on em.

[bmxkelowna]

Hmmm well I guess I'll have to rebuild my ticky legacy 20g heads instead then. Ah well