bored to use sti pistons?
 

if you bored out the eg33 block to sti sized pistons, can you use the stock sti pistons? or are the c/r of those pistons different?

Re: bored to use sti pistons?
 

The eg33 can be bored out to 100mm to fit the sti 2.5 pistons, this should make the engine a 3.5L if my math is right, but will also lower the compression from 10:1 down to about 8.5:1 which is fine for boost but would suck for non turbo power.

Re: bored to use sti pistons?
 

Also FYI, cosmetic makes a head gasket for 100mm and 102mm bores. Just be careful, the eg33 cylinder walls are already pretty thin, so I wouldn't try and go past the OEM STi 99.5 bore. If you go that route there are lots of good aftermarket pistons available.

The only thing I'm not sure about is the piston pin height between the 2.2 (svx size) and 2.5 liter pistons. You would also need to confirm the valve reliefs to maintain non interference status.

Re: bored to use sti pistons?
 

eg33 actually has very good walls stock, but once you bore them they do get thin.

Youre really better getting purpose made pistons in the correct size.