thewhitewarrior

hi,
is it possible to convert a 2L to a 2.5L, or are the cylinder sleves different castings totaly?
thanks phil.

Splitpin

Different castings completely. It's theoretically possible to bore and re-line an EJ20 block but it'd be a fool's errand given that you can get them off the shelf from Subaru.

Mus

iTrader: (2)

if you want to start of with a closed deck block then yes

STI_Baly

iTrader: (23)

Phil i actually thought you already had a 2.5 CDB? From the last conversation a while back with Daz Davies.

In regards to the castings yes they are different internally as the liners are a larger diameter giving you more of a bore than a 2.0. And the 2.5 is already a rear thrust crank where as the 2.0 is a centre thrust again the 2.0 can be machines to accept the rear thrust. at a cost of usually 150+.

You will find that the blocks are the same size though allowing direct fitment in place of the 2.0 litre and the 2.0 litre heads bolting directly to the 2.5 although it is advisable to have these heads combustion chambers ported slightly.

bluerigster

iTrader: (9)

With resleeving any block the sleeves are devorced from the block itself and only stay in postion through the pressure they exsert. So it's known for the sleeves to move and cause head gasket failures and even crack due to fractures sustained from the proceedure of pressing the sleeves into the block to start with. So a standard cast closed deck block would be a safer option over a resleeved block and if you wish to build a large displacement engine capable producing over 500 bhp I'd choose a stroked EJ22T over a resleeved 2 or 2.5 litre.

thewhitewarrior

thanks for the answers, STI_BALY i think you may be confusing my project rs200 with the other impreza rs200 that had a 2.5 conversion, sorry, although you have helped me many times in the past.
how much can a cylinder be bored out by?
is it enough to make it a 2.2 or is a 2.2 a different engine again?
and whats the stroked bit?
sorry for the questions but ive never really looked into anything other than the 2.0 bored .5 over.

bluerigster

iTrader: (9)

Pistons are manufactured upto 1mm over size so it's possible to rebore and hone a block upto this size. The EJ22T block is the largest closed deck block that Subaru produced with under piston oil squiters and was originally fitted to the SOHC 2.2L legacy turbo between 1991-1994 and was available in north America only. Later Subaru released the EJ22G closed deck block with no under piston oil squiters which was fitted in the Impreza 22b and the legacy BF7 and BFB version but sold only in Japan, but 18 22b's where imported offically into the UK. Subaru don't make either blocks anymore but remanufactured blocks are available and easier to source from North America.

The EJ22T & EJ22G CDB uses a 75mm stroke crank as standard so it's possible to use a longer 79mm crank from the 2.5 litre EJ257 block with standard length rods and shorter stroker pistons to increase the displacement to 2.33 litres. A 1mm over bored stroked EJ22T has a final displacement of 2.4 litres but is a stronger engine than the 2457cc EJ257 block with only slightly less displacement but capable of handling 500+ bhp using the correct internals.

thewhitewarrior

i see now, as i doubt ill find a 2.2 ill utilise the 2L cdb i have,
right, so the 2.5 crank is ok to fit in the 2L cdb thats been machined to fit the end thrust bearing? and you can either go with shorter rods or shorter stroker pistons for bigger combustion space?
the only thing different about the 2.5 crank to a 2L crank is the 2.5 crank has a 79mm stroke, which is longer than the 2L crank?