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EJ221/25D frankenmotor build start and compression questions

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Hey all,

My old piston slapping JDM EJ25D has finally started making "you should probably get something on the back burner" noises. Between 4 legacies and 5 engine swaps amongst them, I've decided EJ22 is the way to go since EJ25Ds seem to blow up if you look at them funny. As a result of that, I have 6 good EJ25D heads in my basement (and two in my car). There's a clean, low miles EJ221 in my local junkyard, I want to slap the ej25d heads on that for a bit more power since I'm running 5" of lift and trying to turn 29" KO2s through a 5 speed.


I'm hoping someone here with a lot more experience than me can help out, and sorry for dumping all the questions now, I'd rather be safe than sorry.


EDIT: Here is the post I'm using as a reference:



My questions are:

-what compression would I be around with what head gaskets with USDM EJ25D heads on a 221 block?

-the only post I found says that two different EJ221s exist with different size pistons, how do I identify which is which?

-since the JDM EJ25D is higher compression, does anyone know the if head volume is different on the JDM engines for higher compression or just the pistons, and if so by how much?

-if I end up around 10.3/1 comp as the post says, will that be safe on 91-93 octane?

-I shouldn't have any issues running the phase 2 block since all the electronics are on the intake manifold and heads that will be from the EJ25D, right? Or are the crank/knock sensors different?

-is the crank trigger the same on the phase 2, and will the EJ25D timing belt be the thing to run?


Thanks for any input.

Edited by pginter96

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Put the D heads on a 1999 to 2004 EJ251 block with 770 gaskets and a 10mm oil pump. Don't bother with the 2.2. Won't make any more power with D heads, and they have serious oil burning problems. Rings are dealer only... etc. Waste of time.



Edited by GeneralDisorder

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