EJ22T with EJ25d heads

tturnpaw · Post by **tturnpaw** » Thu Oct 15, 2009 11:54 pm

Ok so im ordering gaskets for my hybrid setup. I know EJ25d heads on an EJ22t shortblock will produce 7.5:1 compression. Im not sure on the head size (54cc?) but I want to bring my compression up to 8:1 or just a little higher.

So the ej22t head gasket size is .051 and i can order .045" (1.14mm). What compression would that set me at?

93forestpearl · Post by **93forestpearl** » Fri Oct 16, 2009 12:03 am

Keep in mind the pistons protrude above the deck on a EJ22T. Just a hair under .020 IIRC.

tturnpaw · Post by **tturnpaw** » Fri Oct 16, 2009 2:56 am

.025 is pretty edgy i know. I am still curious on the compression.

smh0101 · Post by **smh0101** » Sat Oct 17, 2009 6:05 am

With a stock ej22t the compression ratio using .045" gasket would be 7.93:1

smh0101 · Post by **smh0101** » Sat Oct 17, 2009 6:05 am

And head size is 47cc... 46.2 to be exact

Furnace89 · Post by **Furnace89** » Sat Oct 24, 2009 2:43 pm

good reference: http://wac.addr.com/auto/obs/turbo/ejcalcs.html

Im looking into doing the same head swap at some point.

With the thin SOHC gasket you could have 8.0 cr.
Has anybody tried this? How does it holdup under boost?

93forestpearl · Post by **93forestpearl** » Sun Oct 25, 2009 12:23 am

That gasket is too thin to run safely on a 22T shortblock.

MikeyMeyagi · Post by **MikeyMeyagi** » Wed Oct 28, 2009 12:00 am

mines been running for about a month, i used the oem 22t gaskets and the 25d heads. car runs awesome.

vipergtrdj · Post by **vipergtrdj** » Wed Oct 28, 2009 12:50 am

i was reading through the posts and curious how you guys got the engine to work with a SOHC ecu ? I tried this build just it was a ej22e/ ej25d heads and i could not get it to start. It would crank and crank, but not turn over. I used the crank and cam sprockets from the SOHC ecu and still nothing - timing was dead on as well. It was also throwing a code P0336 i believe (crank signal one) but I tried swapping sensors and it still threw it.

smh0101 · Post by **smh0101** » Wed Oct 28, 2009 1:03 am

What car?

Assuming it was a Legacy turbo... which is highly unlikely because you would have gotten a code 11 and 13 for crank and cam sensors for what you did. Your supposed to use the DOHC Cam gears. NOT SOHC ones. It wont work because the triggers are off... If you use the DOHC cam gears the ecu wont be able to tell the difference because all the triggers are the same for the timing. But you CAN NOT use the SOHC gears and make it work.

It looks like that is an OBDII code even so what I said still holds true. Use the ej25d cam gears, make sure you use the correct timing marks and try again. Hopefully you didnt have the timing off and fuck up the valves.

Hopefully this helps

vipergtrdj · Post by **vipergtrdj** » Wed Oct 28, 2009 1:12 am

I tried that after using the sohc gear and it didnt register with the ECU -- the car was a '01 impreza L, the stock cam gear only had 2 triggers on it, and the crank gear has a bunch - like 35 or so small teeth. The ej25d cam gear wouldnt work with the L ecu due to the cam and crank triggers being different.

smh0101 · Post by **smh0101** » Wed Oct 28, 2009 1:15 am

The cam and crank triggers are supposed to have different amounts of teeth!

Use the crank gear that came on the stock motor and the DOHC cam gears and it should work.

Whats the stock engine? ej253?

vipergtrdj · Post by **vipergtrdj** » Wed Oct 28, 2009 4:29 am

no stock engine was a ej22 and i know they are different teeth -- im talking about different between the two heads - the cam gears are different from the dohc to the ej22 heads that were stock

smh0101 · Post by **smh0101** » Wed Oct 28, 2009 7:11 am

Oh... thats not what you said...

You'll need to find a DOHC cam gear that has the same number of teeth as the SOHC cam gear... I'm not sure what that would be off of...

I'm not completely sure... but 01 may be the year they switched to the newer cam and crank signals...

Either way... you cant just swap the cam gears and use the same timing marks...

Their may be a way to set the timing belt up in the right way to run the SOHC cam gear on the DOHC heads. But I dont know what that would be.

How many teeth are on the ej22 cam gears and how many on the 25d gears? Are you sure you have the right cam gears for the 25d? Idk if they even fit... but you sure they arent WRX gears?

vipergtrdj · Post by **vipergtrdj** » Wed Oct 28, 2009 7:10 pm

Sorry for not explaining completely, The (stock ej22)SOHC cam gear only has 2 teeth on the back, while the DOHC has 7teeth (believe its 7). I am positive the DOHC gear is from the dohc motor , I pulled it out of a '99 legacy. I think the '01 is the newer style but I have seen 02+ WRX have the same timing gears as the '99 legacy - so I have no clue what the timing stuff on my '01 impreza - old or new.

smh0101 · Post by **smh0101** » Wed Oct 28, 2009 9:13 pm

well I just talked to a friend of mine...

Basically you cant run those heads.. You have to run the newer style... Like off of a WRX or LGT or FXT... which I believe are all the same.

So when it all comes down to it the only way your going to be able to run those heads is is with a custom cam gear or a Standalone.

You need WRX heads.

93forestpearl · Post by **93forestpearl** » Wed Oct 28, 2009 11:54 pm

One thing to keep in mind with the 25D head swap is that the N/A camshafts are counter productive on a turbo motor. The overlap of the N/A cams is as high as 10-15 degrees. Turbo cams generally run less than 3 degrees of overlap so your boost pressure doesn't blow right into the exhaust.

For instance, Derek's car, with 25D heads, only made 300whp at 28 psi from a GT3782. The car is most likely over rich too, with all that oxygen going straight into the exhaust causing the wideband to display a leaner condition than reality.

tturnpaw · Post by **tturnpaw** » Mon Jan 25, 2010 10:53 pm

So, im bringing this back. I have a few questions about the water pump. If i do the turbo coolant feed and drain off the head like this thread http://bbs.legacycentral.org/viewtopic.php?t=25770 than why would i need the 2nd outlet off of the water pump if it isnt for the turbo? If i install the coolant tube and crossover from the 2.5, and drill and tap the head, what would this other outlet go to? The ej22t coolant canister?

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EJ22T with EJ25d heads

EJ22T with EJ25d heads