Using the EJ20 Cylinders on the EJ25 Block? HELP
 

greetings,

:confused:

I have a wrx from '97, it had about 320hp with stock internals, and after a while doing some tracksdays plus daily use I'd blown my engine block, now I'm think on buying a Cosworth EJ25 block my questions is simple,
Can I use the oem wrx 97 Cylinder Heads on the EJ25 block?
without changing the ecu system plus the admision sys and the exausth sys and so on....
Will it be a reliable engine?
could anyone give me any advices of whats the best to do
thanks to all

regards
pedro
:luxhello:

yep you can use them, however they wont be ideally matched to the block. Is your existing block totally knackered or is it salvageable?

If it is salvageble then just get it rebored, get uprated pistons, new crank and bearings etc cost will be comparable I imagine to the 2.5, but will match your existing heads and turbo etc.

i would also strongly recommend a remap.

thanks for the quick help,
well the block is totaly knackered, no way to rebuild, what is the problem on the matching the ej25 block with the ej20 heads?:confused:

I want a forged block prepared to make at least 8000rpm, and of course more reliable then the stock internals.
I'm thinking on getting the whole EJ25 Cosworth block pack the crank the rods, and the pistons, using the ej20 heads, and of course remap to make 8000rpm, pulling at least 400 or 450hp.

If used the ej25 heads I will had to change the whole electrical system right, plus admission+exausth system?


Is it reliable to do the ideia of the ej25 cyliders with the ej20heads?


thanks a lot mate :notworthy

apexi ecu, of course to make 8000 rpm like a said above... thanks for all the help till now...

I'm open to suggestions & advices!!!

thanks to all :luxhello:

you can get some work done to the heads to better match them to the bore of the block. If you want the 8000rpm limit though you may be better going the 2.33 route which is argued to be the dogs danglies. I think to have a 2.5 that revs safely to 8000rpm will need a lot of money spent on it. Also maybe think about the simtek ecu instead of the apexi. I had the apexi on mine (only a standard 2 ltr wrx engine ), but from what I have read the simtek seems superior and is newer technology

I am using 2.0 l heads with 2.5 Block and have had no problems, as long as you have forged rods and pistons you can rev a 2.5 l to 8000 rpm, however the standard 2.0l wrx heads are not made to rev to 8000 rpm, so you will find the power dying off over 6000 rpm.

To go to 8000 rpm you will need uprated Cams & valvetrain etc..

As above and i would also have the combustion chamber face on the heads machined out to the diameter of the EJ257 head gasket.
STI version 3 and 4 heads would be far better for the revs you are looking for.

Mick

Absolutely, MY97 EU/UK/WRX heads aren't designed for 8k

could anyone advice me a nice cheap (lol) TUner's please...

regards
pedro