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America does lag.



The EJ22T will bolt up with the EJ22 heads, but the EJ22T was designed to have an 8.0:1 compression ratio. The Phase II heads might slightly bump compression, but I'm pretty sure the bulk of the compression ratio increase was in the piston redesign. Either way, the EJ22T was a Phase I motor, so there are some differences between the heads off the Phase II EJ22, and the heads off the EJ22T. For one, the Phase II EJ22 you're looking to use the heads from had solid valve adjusters. The Phase I had hydraulic valve adjusters. The advantage to solid adjusters is high RPM torque and power (No valve floating) with less resistance on the motor, especially at startup where oil pressure is too low for the hydraulic valve adjusters to work correctly. The drawbacks are a reduction in reliability (As the valves must periodically be adjusted). The Phase II heads you're looking to use also had a different (More efficient) valve angle. The redesigned valve angle helped reduce valve shrouding, a condition where the cylinder walls would actually impede the flow of combustion gasses through the valve and into the combustion chamber.


All in all, If you rebuild the stock EJ22T block and install a rebuilt pair of Phase II EJ22 heads you're looking at about a 5-10 HP increase in power. If the compression ratio takes a considerable jump you'll get considerably more power, but with decreased reliability. If this is the case, you can cut back the boost or have custom head gaskets made to get the engine to last. If longevity is none of your concern, leave the boost and stock head gaskets and run it hard till the gaskets or rings give up.


Another popular swap to consider is the DOHC EJ25 heads. They will also bolt onto the EJ22 and will give you more power and torque. They will have similar throttle response, but the engine will decelerate slower due to the increase in rotating mass, and decrease in reciprocating mass (Since you now have 4 rotating camshafts and no reciprocating rocker arms). The combustion chamber design is similar to the Phase II EJ22 (Pentroof style with similar valve angles), but the spark plug can be located in its optimum position in the center of the combustion chamber since there is no longer a camshaft to get in the way. This promotes better combustion and a more efficient burn of the combustion gasses. Xcelleration sells drag racing longblock engines with a bored out EJ22T block and DOHC EJ25 heads that is said to be a bulletproof horsepower monster on the drag strip.

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F*** sohc heads, if you're chucking heads onto a 2.2 turbo block, go DOHC. 25D heads could work nicely. Only reason the 22T was SOHC is cause SOA is naf.


25D heads are very similar to JDM turbo heads of the same year. Physically it's almost impossible to tell them from WRX heads. The difference though i'm sure will be in the cams and valves, and of course lack of oil return hole.

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