NAD226

Hi everyone, I have bought an imported legacy GTB (EJ20) engine to go into my impreza. The book spec for this says 280BHP. What level of internal components ie pistons, rods and crank would be found in this. Are they going to be the same as I have in my standard Turbo 2000 impreza engine?

Bob Rawle

Pretty much, compreession ratio is higher though so more fussy on fuel, stick to Optimax and use some booster.

bob

NAD226

Thanks Bob. Would you advise changing the pistons, rods and maybe the crank as well if I am looking to run around 300-350 BHP on this engine before fitted it in the car, or is there any other work that could easily be done to improve its performance?

Tim W

iTrader: (1)

300-350 should be acheivable on the stock internals, which will be cast pistons, forged rods and a forged crank.

If you're feeling brave you could possibly run up to 400 brake on those internals, although you would be pushing your luck and you would need to be very aware of what you were doing.

If you want to push beyond the 350 brake threshold it would be advisable to look into fitting some forged pistons and even some better rods.

The crank however should be fine, stock Subaru cranks have been used in quite a few of 500 brake plus monsters

NAD226

Is there any particular forged pistons that you would recomend, also if I am stripping the engine to replace the pistons what type of head gasket would be good for that power?

STI Craig

i use wiseco pistones,

they have done me good so far, if u do a search in google u will find a american company that will ship them to you youll save loads, even after the import tax.

i did anyway

STI Craig

use a tripple plate matal head gasket which is fitted to the STI 4 (or might be 3) and on, anyway u can get it from subaru/graham goode.

and its only £5 more than the crappy card tin foil one, so well worth £95.

NAD226

Thanks craig, out of interest does anyone know how good the heads are on the legacy GTB engine, are they the same as the WRX or STI impreza heads?

Tim W

iTrader: (1)

Probably the same as the WRX, the best way to check is to look at the cam followers, if they have shims between the cam and the follower then you have 'overbucket shims' (stock WRX) if the shims are underneath the followers acting directly on top of the valve stem then they are underbucket (as found on Sti's from the version 3 on)

As for parts I'd say speak to Zen Perfromance, Lateral Performance and/or Roger Clark Motorsport for options