Jump to content
Ultimate Subaru Message Board
Marter_Templar

Impreza EJ18 with Ej22 Pistons, its possible?

Recommended Posts

Hello guys, i have with me one set of EJ22 pistons and rings STD Brand New, and i want to know, if its possible to use the EJ18 block with the EJ22 Pistons, just resleeving with new size? , this combination will be perfect if its possible because i can use our national fuel (etanol) with the hight compression ratio that will result for this change, so, with new sleeves , will be possible use the EJ22 pistons on my EJ18 block? , tks

Share this post


Link to post
Share on other sites

Thats a 9mm bore size difference. Not sure if there is enough room. Your gonna have to measure it andd confer with a machine shop most likley.

 

Not only that but the cost of making this work will probably be more than just getting an ej22 block.

 

The stroke on both motors are the same but your also gonna need to measure piston skirt length and wrist pin hole location as well.

 

I am also not sure your comp ratio would go up. Both motors had about the same comp ratio.

 

IMHO not worth the hassle. I may be wrong though because I have never tried it...

 

Hopefully some of the motor builders here will chime in. I am no expert by any means...

Edited by WRX2FFU

Share this post


Link to post
Share on other sites
Thats a 9mm bore size difference. Not sure if there is enough room. Your gonna have to measure it andd confer with a machine shop most likley.

 

Not only that but the cost of making this work will probably be more than just getting an ej22 block.

 

The stroke on both motors are the same but your also gonna need to measure piston skirt length and wrist pin hole location as well.

 

I am also not sure your comp ratio would go up. Both motors had about the same comp ratio.

 

IMHO not worth the hassle. I may be wrong though because I have never tried it...

 

Hopefully some of the motor builders here will chime in. I am no expert by any means...

 

i sure the comp ratio will increase, and i am from brazil, its impossible to buy an block, tks

 

Won't work, liner thickness is only 4 mm so you really can't bore more than 2 mm in total.

 

but i will resleave the block with EJ22 sleeves, why this will not be possible? tks

Share this post


Link to post
Share on other sites

The ej22 sleeve is 9mm larger on the inside. I am not sure of the thinkness of the sleeve itself. I sure it can be decreased a bit. I am just not sure that there is enough room on the block itself to fit them.

 

You could be getting into coolant passages, also might run into crank clearance issues on the bottom.

 

Without taking measurements I can't be sure. Sounds like a ton of work just to make some free pistons fit.

 

I did some basic CR figures and I guess your right. The CR would be in the 9.7:1 to 10.5:1 range. Really only about 1 point over stock though. That also depends on which heads your using and which head gasket as well

 

Also I am not sure of the differences in piston deck clearance.

 

Basically I believe unless all the measurements are made and then calculated no one would be 100% sure, unless they have done it... which I am not sure anyone has.

Share this post


Link to post
Share on other sites
The ej22 sleeve is 9mm larger on the inside. I am not sure of the thinkness of the sleeve itself. I sure it can be decreased a bit. I am just not sure that there is enough room on the block itself to fit them.

 

You could be getting into coolant passages, also might run into crank clearance issues on the bottom.

 

Without taking measurements I can't be sure. Sounds like a ton of work just to make some free pistons fit.

 

I did some basic CR figures and I guess your right. The CR would be in the 9.7:1 to 10.5:1 range. Really only about 1 point over stock though. That also depends on which heads your using and which head gasket as well

 

Also I am not sure of the differences in piston deck clearance.

 

Basically I believe unless all the measurements are made and then calculated no one would be 100% sure, unless they have done it... which I am not sure anyone has.

 

hummmm, maybe i will try to do that, rope it works :D

Share this post


Link to post
Share on other sites
Well, it's worth taking measurements to see if it will work.

 

It won't. The aluminum barrel around the liner on EJ blocks is only about 10mm thick.

 

The barrel is is cast different sizes depending on whether it's a 18, 20, 22, or 25.

 

To bore out a 18 to 22 you'd have a barrel that was about 2mm thick at the top edge, and that would be all Aluminum. there Physically is not enough meat to "resleeve" the block.

 

Besides, these blocks don't have conventional sleeves anyhow. they are not pressed fromt eh top, but rather encapsulated in the block when it is cast.

 

Maximum oversize bore on ANY EJ engine is .25 mm. They cannot be resleeved. Period.

Share this post


Link to post
Share on other sites

Agreed, except the oversize. Factory max is 0.5 mm but generally 1.0 mm is considered the maximum oversize on stock liners.

 

Re-sleeving introduces all sorts of problems as the block is not designed to take sleeves, it is not stable enough to support the bottom of the sleeve which causes head gasket issues sooner or later (but probably within a few thousand kilometers - if the sleeving has been done well). Stay away from sleeves unless you are willing to spend the time, money and effort re-sleeving and re-decking the block time after time.

 

Why don't you try to source a set of EJ22 block halves and fit the pistons you have? The EJ18 crank is the same anyway. In the long run it will be much cheaper and easier.

Share this post


Link to post
Share on other sites

I didn;t think it would work either. Just not enough room in the block itself.

I just did not have any concrete numbers other than the bore size differences.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×