legacycentral bbs

Yup, again some pics !! haha

We tried the ej20(G?) heads of my friend (the one with the STI V2 that is not one (refer to Off-Topic ).

Seems to fit A-1 exept 2 little things :

1 - On the driver side heads, there is 2 holes on the ej22T gaskets that are a bit offset and dont match the holes on the head.. a little bit of drilling and it's fine

2 - On the ej22T gasket, there is 2 holes that are there for nothing on the ej20(x) head. just ignore it .. hehe

All the pics and HiRes :
http://public.fotki.com/morgie/morgie/o ... _on_ej22t/


I'm pointing the 2 holes that leads to nothing on the ej20(x) head.


This what is under those holes on the ej22T heads...


Size Comparison.


Perfect Match.

Nice! The EJ22T bottom-end is already tough enough, and now with DOHC heads, you should be able to pursue some higher RPM's

However, will the EJ22T manifolds bolt up to those heads, or have you already planned to swap them?

I think EJ22T and EJ20G exhaust manifolds are interchangeable...I could be wrong...but I think they are. And then as far as the intake manifold, is there any reason not to just use the EJ20G intake manifold if you have it...it will leave you more room for a top mount IC cause it mounts the TB farther forward.
looks great there morgie! Kinda looks from the pictures like the EJ20 heads might have slightly bigger exhaust and intake valves...like they should flow better. Does it look like that in person?
thanks
Micum

subyluvr2212:
Humm that's something i forgot to check... but i guess it'll fit .. the ports look to be at the same place.

Unfortunately, those heads wont go on my setup... (but i think i'll try to find some now !! haha). They belong's to my friend that i succesfully convinced to buy an Ej22T to rebuild his engine .. hehe (ej22t shortblock + all the externals of his EJ20G (intercooler, td05, DOHC heads, GEMS ecu)

might become another monster .. hehe future will tell.

Czo79 : You're right, they looked bigger. Will have to measure them to tell with more precision.

I thought the EJ22 had a larger bore than the EJ20. Doesn't that mean there would be a "step" area around the edge of all the ports where the heads mate with the block that could affect flow?

vrg3 : look at the shape of the ej22t heads ... notice the top and bottom sections that are "straight" and flat ... that's a bigger step ! hehe also, look at the "dirty" part... the "hole" is smaller than the bore of the engine.

don't think that would madder that much. The Ej20 heads has a much deeper combustion chamber.

Copy this URL and paste it on a new Internet explorer.
http://images4.fotki.com/v40/free/0e39a ... IMG-or.jpg

On the left, is a ej22T head. Notice the "dirty ring" on the combustion chamber that is on the top of the picture ... You can see where the gasket finish with the beige-ish part. You see that it's not a "Flush-fit" (damn it's hard to write this in english... hehe)

Now on the right, you have the Ej20G head with the EJ22T gasket on. You see that is not a flush-fit neater. The combustion chamber is also smaller than the hole of the gasket.

Hmm, very interesting. So you'd end up with completely different combustion chamber geometry. I wonder how much engineering went into designing that shape, and why it would be so different between two such similar engines. Maybe it just doesn't matter too much. I'd guess that the airflow and revving advantages would probably outweigh this problem if it even exists.

So is he just gonna use a stock Phase I EJ25 or WRX timing belt and associated parts? Do they fit up?

Thanks for sharing all the info and pics, Morgie, and for dealing with the trouble of writing in English. Very much appreciated.

Yes, info is much appreciated!

vrg3 and morgie, do either of you know exactly how close to the head the piston is at TDC? Does it actually go slightly above the block? If so, then if the EJ20 heads have a smaller area that is actually in the combustion chamber, wouldn't the piston slap the head??? I thought that was mentioned in the EJ22T notes thread that was stickied, that the piston goes slightly above the block...

I have effectively noticed that the ej22T pistons goes out of the block slightly. and on the ej20t, it don't .

But as I said , both the ej20t and ej22t heads have smaller combustion chamber than the cylinder bore. As long as you use the same gasket (0.150mm), there should be no problems.

Okay cool, but now, are you making an interference engine (piston to valve) out of an engine that once wasn't? Better keep up on timing belt changes

I thought all Subaru quad-cam engines were valve-to-valve interference.

interference, you mean, valves clears the pistons ? that's a test i can't do for now since my block is in pieces... but i'll definitely to the test with a slice of orange cheeze or some paste to check that.

Well, there are two kinds of interference: valve-piston and valve-valve. Either one means bad news if the timing belt breaks.

humk, but Valve-Valve clearance is nothing i could do.. should be ok since it's a stock head (as long as the cams and valve-lifts stay the same)... but valve - Piston is something i'll have to verify

I know for a fact that DOHC EJ25 heads are valve-valve interference. My point is that if the EJ20 heads are valve-valve interference then it doesn't matter too much whether the pistons can hit the valves, since it's already an interference engine.

Yeah you're right, I forgot all DOHC Subaru heads were valve interference...