EJ22T Pistons

Heads, valves, pistons, rods, crankshaft, etc...

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LSiTurbo
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EJ22T Pistons

Post by LSiTurbo »

Want a cheap alternative piston for the EJ22T without going forged or hopefully be able to find O/S OEM pistons. Well I may have found a solution that I don't think has been done before ( I searched but not that hard).

So a little back story. I got a bunch of parts to do an EJ22T w/ EJ20 heads swap into my 95 Legacy LSI wagon. Right now I'm running all OEM WRX stuff, injectors, turbo, and have got the ECU wired up and working for tuning just to get the thing running. However the block had some minor pitting on the cylinder walls and I (at the time) did not want to pay for new pistons and bore to get it running. So I just honed it till the pitting was gone and put it together and as you probably can guess it started making all sorts of bad noises. I knew I had to get new pistons and there was no way in hell I was going to go forged because I don't have those power goals and I DO NOT want to spend that much (full time engineering student = not that much money). I then decided to do the same thing I have done with the motors I have built with my AE86. Find an OEM part from another manufacture that will fit.

I went through a lot of catalogs and books and came across something that stands a VERY good chance of working. The Buick L67 V6
Specs-
Bore - 96.5mm
Wrist pin - .905 x 2.5 (23mm x 63.5mm)
Compression height - 1.197 - 1.2 (more on this)
Dish - I think -13 cc (More on this)

I'll start with the compression height. This is about 0.1 lower than the OEM EJ22T piston so this means that there will be a big compression drop, however, since the pistons is now down in the hole there is no more fear of making piston to head contact so just run the very thin EJ22E head gasket.

Then the dish of the piston. I'm not entirely too sure yet but there are no consistent numbers on OEM dish size. The numbers that I have seen from after market pistons for the L67 state that at a 1.205 compression height (about 5 thou higher than OEM) they are using -13.3cc's of dish to achieve 8.5 compression w/ OEM head gasket. Since the OEM compression of the L67 is 8.5 and those pistons having 5 thou higher compression height its safe to ASSume they are -13cc's. This will also bring the compression up for the EJ22T.

The other good part about this. The L67 is a supercharged engine so these pistons are designed with boost and LOTS of heat in mind (some manufactures will anodize the piston crown) so they should be able to withstand a good beating. Combing the now mostly dead forums for the L67 most of those guys were breaking rods before the piston gave out but there is the occasional piston crown breaking. Could be bad tune or just bad piston.

I did save the best for last though. These pistons can be had off of Rock Auto for a the small price of $24 a piston and they are offered in a 0.75mm oversize. Bringing the final bore to 97.25mm perfect for a minimal bore and hone.

And to be sure that I'm not just talking to talk. I have put my money where my mouth is and ordered everything. Should be here Friday all I need now is to find a shop to do the machine work needed for a reasonable price and ill start assembling it.
Last edited by LSiTurbo on Thu Oct 26, 2017 5:23 pm, edited 1 time in total.
jefferson
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Re: EJ22T Pistons

Post by jefferson »

That v6 is a 2 valve motor isn't it. What about valve relief pockets?
91 Black SS 5spd. Edm lights, wrx gauges in dash, 45 degree airbox, cryoed drilled and slotted brakes. Invidia divorced downpipe with custom stainless exhaust. To be installed, aluminum a-arms, manual belts, awic.
LSiTurbo
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Re: EJ22T Pistons

Post by LSiTurbo »

Yup they are a 2 valve and valve relief pocks are not there. But it has the same style of dish cut as the EJ22t and those have a very minor relief cut. I will assemble the motor and check clearances with some clay will adjust after if needed.

But you do have to keep in mind that with the OEM specs the EJ22 had about 1.3-1.0mm piston to head clearance. These piston will have 3mm piston to head clearance. Valve reliefs may not be needed but like I said I will measure.
cj91legss
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Re: EJ22T Pistons

Post by cj91legss »

This is interesting.
91 L-TW Wagon with a full Swap -RIP
92 SS Prefaced, GD dash swapped, 22T/205 Hybrid 20 psi - BEAST!
93 SS Bone Stock Gone!
94 TW Bone Stock Gone!
91 SS 4EAT Sold!
98 LGT 4EAT
98 LGT Wagon 4EAT
EJ22D
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Re: EJ22T Pistons

Post by EJ22D »

LSiTurbo wrote:I'll start with the compression height. This is about 0.1 lower than the OEM EJ22T piston so this means that there will be a big compression drop, however, since the pistons is now down in the hole there is no more fear of making piston to head contact so just run the very thin EJ22E head gasket.
Problem:

You cannot use EJ22E head gaskets with EJ20 heads, assuming you are running DOHC heads. The coolant passages to the head through the head gasket do not match up.
monkeyposeur
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Re: EJ22T Pistons

Post by monkeyposeur »

^Good point. I found some pics that may support that here: viewtopic.php?t=42127

I've used OEM EJ25D gaskets on a 22T/205 hybrid and it matched up very well with the coolant passages of the 205 heads and 22T block. Wonder if the OP could use them for this build.
93 SS - SOLD
03 WRX 22T/205 20GXT 350 whp
06 OBXT
95 BK - Sold to my neighbor.
EJ22D
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Re: EJ22T Pistons

Post by EJ22D »

monkeyposeur wrote:^Good point. I found some pics that may support that here: viewtopic.php?t=42127

I've used OEM EJ25D gaskets on a 22T/205 hybrid and it matched up very well with the coolant passages of the 205 heads and 22T block. Wonder if the OP could use them for this build.
EJ22T head gaskets are his best bet, or going custom to bring the thickness down to exactly 1mm.
LSiTurbo
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Re: EJ22T Pistons

Post by LSiTurbo »

Umm yes the 1999-2001 ej22 head gaskets line up perfectly with the EJ20 heads I wouldn't be using them if they didn't. Modifying head gasket is a thing I never do. Ill get some pictures when I can.

Also the point of running of running this is you need the thinnest head gasket you can. Running an OEM EJ22T will leave you with a CR below 7:1. Yes you can get a custom head gasket made for the EJ22T. But why do that when you can get a MLS Felpro for $25 a piece.

And dropped the block off at the machine shop earlier today. It's a good shop but a busy one so I'll get it back probably next week.
LSiTurbo
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Re: EJ22T Pistons

Post by LSiTurbo »

Finally able to get back to this. The engine is up and running beautifully with the exception of a oil leak I'm tracking down.

Have some pictures off the pistons sitting at TDC in the block before I sent it back out for the final decking and cleaning and you will have to excuse me I'm not much of a picture taker and my phone has a ok camera.

Image
Aki
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Re: EJ22T Pistons

Post by Aki »

Very nice! Be sure to post some updates through the life of this engine, curious to see how these hold up.
cj91legss
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Re: EJ22T Pistons

Post by cj91legss »

Yeah this is definitely pretty cool!!!
91 L-TW Wagon with a full Swap -RIP
92 SS Prefaced, GD dash swapped, 22T/205 Hybrid 20 psi - BEAST!
93 SS Bone Stock Gone!
94 TW Bone Stock Gone!
91 SS 4EAT Sold!
98 LGT 4EAT
98 LGT Wagon 4EAT
LSiTurbo
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Re: EJ22T Pistons

Post by LSiTurbo »

Absolutely, my new o2 sensor comes in tomorrow and will be doing some WOT tuning soon, see how things go.
monkeyposeur
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Re: EJ22T Pistons

Post by monkeyposeur »

This is so cool!
93 SS - SOLD
03 WRX 22T/205 20GXT 350 whp
06 OBXT
95 BK - Sold to my neighbor.
jamal
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Re: EJ22T Pistons

Post by jamal »

Yeah, that's neat. Were you able to calculate compression ratio? How far in the deck are they?

2mm longer rods are pretty readily available. Or, conversely, a 2.5 crank could be used if there's that much room. These might be a way to make a super budget 2.34 turbo block out of a phase 2 2.2.
peter@functionauto.com
LSiTurbo
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Re: EJ22T Pistons

Post by LSiTurbo »

Final compression ratio was 7.4 :1 with using the OEM combustion chamber size of the WRX heads. I used that due to not be able to measure mine correctly but since I had them shaved 0.006 I can comfortably say I'm at 7.5 : 1. And I think final measured for piston to deck height was 0.12 in the hole.

Also I already had all the parts I put in here because I got most of it for dirt cheap (quite a bit free). The STI rods I got were free so using them was a must because I was trying to do this as cheep as possible.
LSiTurbo
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Re: EJ22T Pistons

Post by LSiTurbo »

Just a little update. All is running well!! Have it running pretty good but since I'm only using 440cc injectors I'm limited on what I can do. Pretty much have it hitting around 16psi till about 5k RPMs and have to taper off to 10psi using a 6k RPM redline
jamal
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Re: EJ22T Pistons

Post by jamal »

Good to hear. I made my own compression ratio sheet lately and also get 7.5:1

SOHC 2.5 rods are 131.6mm and that would get it over 8:1 for anyone else looking into this. +2mm rods would be even better but that's a lot of money.
peter@functionauto.com
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Re: EJ22T Pistons

Post by 86BRATMAN »

LSiTurbo wrote:Umm yes the 1999-2001 ej22 head gaskets line up perfectly with the EJ20 heads I wouldn't be using them if they didn't. Modifying head gasket is a thing I never do. Ill get some pictures when I can.
That is an ej221/ej222 you're speaking of. Not an ej22e.

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LSiTurbo
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Re: EJ22T Pistons

Post by LSiTurbo »

86BRATMAN wrote:
LSiTurbo wrote:Umm yes the 1999-2001 ej22 head gaskets line up perfectly with the EJ20 heads I wouldn't be using them if they didn't. Modifying head gasket is a thing I never do. Ill get some pictures when I can.
That is an ej221/ej222 you're speaking of. Not an ej22e.

Sent from my 0PJA2 using Tapatalk
Ahhh okay, you will have to forgive me I am completely new to the Subaru world and this is my first Subaru. I will make the appropriate changes to where i have this information saved THANK YOU.

And coming back for another update! I have now switched to de-capped WRX injectors right now measured them all at 852cc's @ 43 PSI and have switched to E85. I have also upgraded to a Greddy T518z turbo and pushing a healthy 23psi. These pistons are taking it all perfectly so now we just have to wait and see how long these last.
monkeyposeur
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Re: EJ22T Pistons

Post by monkeyposeur »

Wow, that sounds awesome! :)
93 SS - SOLD
03 WRX 22T/205 20GXT 350 whp
06 OBXT
95 BK - Sold to my neighbor.
Omega79
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Re: EJ22T Pistons

Post by Omega79 »

Jeebus! So did you ever determine what the piston material or coating is? I may seriously consider this for my 22T and save money for the crank and rods.
lucas wrote:There were multiple Legacys with 300k+ miles. Jesus will return on a Turbo Lego.
mittens
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Re: EJ22T Pistons

Post by mittens »

Looking forward to further updates!

You said the piston tops ended up 0.12 in the hole (~3mm)? When you clayed the combustion chamber, how much clearance did you have to the valves? From what I'm reading, a 79mm crank would work perfectly and give a nice bump to compression.

Edit: http://www.csgnetwork.com/compcalc.html

I come up with 8.4:1 cr using your stated deck clearance, an ej257 crank, 25d heads and head gasket. And 8.8:1 with the ej222 gasket.
Last edited by mittens on Wed Jul 18, 2018 5:53 pm, edited 2 times in total.
ride_child
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Re: EJ22T Pistons

Post by ride_child »

yea for reals, get back with some info!!!
Kris

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LSiTurbo
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Re: EJ22T Pistons

Post by LSiTurbo »

Sorry but it will be difficult to update stuff. Currently getting ready to move states, my wagon was hit by a drunk driver and now in the process of swapping everything from my wagon to a forester. So I will try to answer everything right now.

So first the pistons you get from Enginetech are Hypereutectic not cast, from the 2nd ring land up is hard anodized, and has moly coatings on the skirts. The first ring land is the same thickness compared to ej20 and ej25 turbo motors 1.2mm , however, the 2nd ring land is 1.5mm, .3mm thicker than Subaru turbo motors.

And yes the only picture posted here is the pistons are at TDC. They sit 3mm below the deck and as for the valve clearances I can not for the life of me find my notebook where I recorded everything.

Another thing worth noting is that there are two oversized options for the pistons, 0.5mm and 0.75mm. With the stock bore of the ej22t being 96.9mm getting the 0.5mm oversized ones will be 97mm. So those can be used easily with just a good enough hone on the block to fit them in. I HAD to use the 0.75mm oversized ones because my cylinder walls were damaged and had to be bored out. Im stating this because if your block is good enough to where just a simple hone is needed I would go with the 0.5mm oversize ones. Gives you the option later on down the road if you have to rebuild again you can do a 0.25mm bore and be set for the next ones. Because after that we're shit out of luck with pistons lol.

Finally if anyone wants one of my extra pistons to look at and maybe take their own measurements. I have two extra (since you have to buy six at a time). PM me, just pay for shipping and I'll send one your way. Just remember that these ones are at a bore of 97.25mm so they won't fit in your block.

Anything else?
Legacy777
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Re: EJ22T Pistons

Post by Legacy777 »

Just want to clarify, in your post you state 0.5mm oversized. Should that be 0.05mm since you state these would bring the overall bore to 97mm from the stock 96.9mm?

Thanks
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