legacycentral bbs

I am tossing around some motor build ideas. I am looking at doing a full 2.0 WRX (USDM) swap with Weisco Pistons and Manley rods.

OR I have been tossing around the idea of the EJ22T w/ 2.0 WRX heads. If I went this route I would want to build the internals. However I cannot find any standard size forged pistons. I haven't even looked to see if anyone makes stock stroke Ej22T rods.

Or even curious about making a stroker (phase 1).

I saw that stock internals with the 22T HG would yield a 7.4:1ish Comp ratio. Thats a little too low for my liking.

I really don't have any specific feedback on this setup, but can tell you it's something I haven't typically seen. So for probably several reasons people choose to go another route.

No-one has off the shelf stock sized ej22t pistons anymore. CP, Wiseco, et al would be more than happy to take your money in making a custom set I'll bet with machine work, going with oversized pistons would come out far cheaper.

HI,
Assuming you're putting this into one of your listed Subies, What EM are your running? Those heads and IM don't play well w/the OBD1 of the '90-'94 era.
Td

Mike and I have been going back and forth on this because I am doing the same build. He brought it to my attention about using some 22E pistons.

With the compression calculator I have and the 1.30mm cometic gaskets, the compression would be 9:1

Depends on which 22e piston you use, the 90-96 pistons are -14cc and I get 8.85:1 on the calculator, 97-98 pistons are -12cc and that comes to 9:1.

As for the rods, you can use ej205, ej257, and ej255 fitment rods because there the same length as the ej22t/22e rods.

You're right. I used 12cc in the calc. I like the 8.85 better.

If you figure out a CR that works for you with the 49cc combustion chambers, choice of piston and HG, then this setup will work great. The more important question is the the correct choice EM. Either a standalone or the 2.0L WRX ECU can be made to work. Both options will require wiring modification work.

Personally I like the top feed injectors setup and the integrated IAC in the TB that is included with switching to the WRX DOHC heads/manifold.

The 90-96 pistons are stronger than the 97-98 pistons too. I get -14.5cc on the early pistons for dish. I'm building a '91 EJ22e block into an EJ22/EJ205 hybrid for my '99 Legacy right now and have come up with 8.8:1 CR using the thinner MLS EJ22 headgaskets. The thick EJ22t style composite headgaskets would drop CR even further. I'm using the WRX ECU/intake/heads and merging my harness myself.

That sounds like you aren't figuring in the 0.3mm that phase 1 pistons poke out of the block. By my calculations that combo ends up with 9.3:1.

Only the EJ25D and EJ22t pistons protrude 0.3mm. I'm using EJ22E pistons and I just went out to my garage and confirmed that they are flush with the block surface.

Alphius, can you measure the depth at top dead?

For the sake of argument I left out the fact that my block has been decked once, these pistons are .005" or .127mm proud of the deck. Stock EJ22 should be level with or slightly below deck. Measured with a straightedge and feeler gauges several times at several locations around the piston. I measured #1 and #2 and both were the same.

This is a '91 Legacy wagon EJ22e.

Both 22e shortblocks I have in my building have a slight protrusion. If you do the math you will see it to be true. All ej series blocks have a 201mm deck height, ej18/20/22e have a 75mm stroke with 130.5mm rods, and 33.3mm compression height. So with that said, the math: 37.5+130.5+33.3=201.3, 201.3-201=0.3mm out of deck.

I understand the math my friend but I'm just saying I have evidence in my garage right now that disproves the math. Occam's razor says that the numbers must be wrong. I'm guessing piston compression height is not 33.3 but I'm not disassembling this block to find out. In a couple months I might be swapping a friend's '95 EJ22 out, in which case I'll disassemble that block and figure out exactly what's going on. Until then I'll trust my measurements. The Subaru FSM doesn't list piston compression height.

I've hit the compression calculator after just about every post on this thread lol.

My CR calculation specs:
96.9mm bore
75mm stroke
98mm headgasket bore
49.6cc head combustion chamber (EJ205 stock)
14.5cc piston dish

Using the thin .8mm EJ22 MLS gaskets CR would be:
9:1 with the .127mm deck height of my engine
8.9:1 with 0 deck
9.14:1 with .3mm above deck

Using the thick 1.4mm EJ22t headgasket would be:
8.5:1 with the .127mm deck height of my engine
8.4:1 with 0 deck
8.63:1 with .3mm above deck

I wonder what the deal is, I have a 93 and a 97/98 shortblock that both have mild protrusion. Both of them will be coming apart at some point in the near future so I'll see about getting some measurements when I do. But of course you're doing it right using the parts you have in front of you for your final calculations.

Revisiting this because I am trying to wrap my head around some things. First off it would be runnin' a 2.0 WRX ECU with a harness merge.

So I was thinking. Stock Ej22T crank, STI rods (+2 or +4mm length to make up for the stroke difference) or maybe stock length, and the Weisco OTS 0.20 stroker pistons (which I know would have to bore the block out). Does this sound like something that would work? Or am I confusing my self.

I could even run a thinner HG to bring up the comp ratio if need be if I ran stock sti rods (would need to look at a calc to determine quench area).

I thought STI rods and EJ22t rods were the same length at 130.5mm?

My calcs show an 8.55 CR with an EJ22t block, Wiseco .020 over OTS pistons for EJ22t, STI/EJ22t rods and EJ205 stock heads running the thin .8mm MLS EJ22 gaskets. Quench is super tight with that combo so a Cometic 1.3mm HG might be better but that drops CR to 8.18:1. The Wiseco OTS pistons will stick up .25mm over the deck with 130.5mm rods, so there's no reason to build a long rod motor.

They are the same length, the only 2 ej rods that are different lengths are the ej25d and ej251.

Just to add to this, when shopping for rods i found that Manley makes standard rods at 5.137" for the EJ18/20/22/255/257

Following this know nothing about building engines but I have a 22t I want to build as a project! Hope this helps me!!

mike-tracy wrote:No-one has off the shelf stock sized ej22t pistons anymore. CP, Wiseco, et al would be more than happy to take your money in making a custom set I'll bet with machine work, going with oversized pistons would come out far cheaper.

I know JE and CP are the only two that make factory bore 97mm drop in pistons

What did you pay for them?