EJ207 with EJ22E heads

[bd96]

Hi,
First time poster, long time lurker. I'm planned a turbo project for my BD sedan next summer (southern hemisphere). I was just wondering if the N/A EJ22E heads would fit on the EJ207 block? If so, what would the resultant compression be?

Thanks,
Matt

[Garrison]

As a general rule, all subaru blocks can mount to any subaru heads. Now, whether or not the oil ports are correct; I do not know.
If you don't get an answer on the compression ratio, try pm'ing lordflashheart. He builds these engines for a living, so he'd know best.

Good luck, and welcome to the forum!

[bd96]

Thanks for the welcome.

I've determined that the compression ratio would be 9:1, this was worked out using ej22t heads, however there doesn't seem to be any difference between these and ej22e heads. You may be right about the oil ports, comparing the ej207 and ej22e heads through photos there seems to quite a few differences. A little more research is needed.

[Reuben]

You cant fit heads from a larger engine to a block from a smaller engine, you'll get a 'mushroom' shaped combustion chamber which is not good, can only go the other way, say, with a 22 block, and some 207 heads.

And don't use 22 SOHC heads for a turbo build anyway. Just find some ol DOHC turbo heads man, 20G heads make a hell of a good noise!!!

[Garrison]

You cant fit heads from a larger engine to a block from a smaller engine, you'll get a 'mushroom' shaped combustion chamber which is not good, can only go the other way, say, with a 22 block, and some 207 heads.
That is just dead wrong. The "mushroom" effect you're talking about helps to drop the compression of the engine.

why else would there be the ideal option of DOHC 2.5L heads on a EJ222?

[mlitz]

Even the EJ25D heads would be better then the 22E's, shooting for a lower comp. ratio is always a good idea :grin: try not to shoot for over 9:1 static as you wont be able to run very much boost. If you want to run a higher comp. ratio that is fine you will get a faster spool on the bigger turbos and a little more low end power but that's about it.

[bd96]

Even the EJ25D heads would be better then the 22E's, shooting for a lower comp. ratio is always a good idea :grin: try not to shoot for over 9:1 static as you wont be able to run very much boost. If you want to run a higher comp. ratio that is fine you will get a faster spool on the bigger turbos and a little more low end power but that's about it.

Cheers for the info. EJ25D heads + EJ207 gives compression ratio of 8.3 which would be much better, plus mating those the EJ25D heads to the EJ22 wiring loom shouldn't be too much trouble. The main reason I'm leaning towards the EJ207 block, is machining parts where I live is EXPENSIVE, labour costs are ridiculous in Australia. I wouldn't mind an EJ22T either, but these are extremely hard to find. Would most likely have to buy a BC Legacy Turbo just to get the block.

[Reuben]

Large heads plus small block is a very WRONG way to go about lowering compression, it's not very efficient.

But hey, if you wanna go build engines like that, I won't stop yah :D

[Garrison]

It is a very WRONG way to go about lowering compression, it's not very efficient.

But hey, if you wanna go build engines like that, I won't stop yah :D
I'm not sure I understand, and I would like to.
Why is adding more CC's to the combustion chamber not an efficient means of lowering the compression?

[Reuben]

Because cc's are one component of many involved in turning petrol into power. I'll leave you to mate, have fun...

[mlitz]

It is a very WRONG way to go about lowering compression, it's not very efficient.

But hey, if you wanna go build engines like that, I won't stop yah :D
I'm not sure I understand, and I would like to.
Why is adding more CC's to the combustion chamber not an efficient means of lowering the compression?

I am also trying to wrap my head around this?

There are other ways yes, but the other ways require a lot more work and money. Why do you think people expand the combustion chambers on the 2.0l heads when they do the hybrid builds?

[StatGSR]

Why do you think people expand the combustion chambers on the 2.0l heads when they do the hybrid builds?

to avoid hot spots and high stress points at the edge of the combustion chamber that over hangs over the pistons. as a general rule, you want your head bore to match your cylinder bore as best as possible. it helps improve the combustion process and flow of gases.

[mlitz]

Why do you think people expand the combustion chambers on the 2.0l heads when they do the hybrid builds?

to avoid hot spots and high stress points at the edge of the combustion chamber that over hangs over the pistons. as a general rule, you want your head bore to match your cylinder bore as best as possible. it helps improve the combustion process and flow of gases.

It also helps lower the comp. ratio back down to the 8.5 range. Witch seems to be a ratio that Subaru's love to make power at.

[StatGSR]

i would not say its a better CR, its just a safer CR....

[Garrison]

to avoid hot spots and high stress points at the edge of the combustion chamber that over hangs over the pistons. as a general rule, you want your head bore to match your cylinder bore as best as possible. it helps improve the combustion process and flow of gases.
Thank you for actually explaining that to me.

[Garrison]

Evidence to contrary:

http://forums.nasioc.com/forums/showthr ... ?t=2319603 (http://forums.nasioc.com/forums/showthread.php?t=2319603)


Edit: there is confirmation in the thread of the 2.5dohc heads combustion chamber being no larger in diameter than the bore of the 2.2 liter.

[Wiscon_Mark]

Edit: there is confirmation in the thread of the 2.5dohc heads combustion chamber being no larger in diameter than the bore of the 2.2 liter.

That doesn't mean that the heads will work well with an EJ207 though. (Doesn't mean it doesn't) I'd be interested to see how this works though.

[elislider]

this is a tangent that i find necessary to mention for this thread:
The bore of an EJ25 is very similar to the EJ22, because the stroke is longer on an EJ25 than a 22/20/18. So putting EJ25 heads on a EJ22 isnt a big deal, the head dish is barely larger in diameter (2mm) than the bore of the block. but putting EJ20 heads on an EJ25 is way the opposite, the head dish is smaller by about 7-8mm in diameter; the short story is it has higher compression, which can be tuned for, but it also has an area around the edge of the piston face that is nearly squishing directly against the face of the head, and you can't really tune for a mechanical thing like that. some people are able to run hybrid builds (EJ205 heads, EJ257 block) for a long time with no issues, a lot of it is the tune, but at the same time a lot of people have issues with doing hybrid builds and getting rod knock or otherwise blowing something


but back to the OP's question, why would you do this? EJ22 heads are terrible. At least EJ25D heads are halfway decent, and any of the EJ20K STi or EJ207 STI (v5/6 especially) heads are WAY better. I would do those if you can get them

[bd96]

but back to the OP's question, why would you do this? EJ22 heads are terrible. At least EJ25D heads are halfway decent, and any of the EJ20K STi or EJ207 STI (v5/6 especially) heads are WAY better. I would do those if you can get them

Simplicity to be honest, less messing around with electronics. However after reading previous comments and doing some of my own research, I've decided on EJ25D heads as they are still phase 1, with some porting they should flow enough to be useful.

Cheers for the help guys,
Matt

[StatGSR]

25D heads flow enough even without porting. are you boosting or what?

[elislider]

I believe EJ22E and EJ25D heads use a different intake manifold bolt pattern?

there is no such thing as "less messing around with electronics" when you are talking about boosting an NA car. Either you keep the car NA, same-ish compression, and dont change any wiring, or you do a custom build and get engine management, and that always requires wiring. or you just do a complete swap to a different style of engine and merge harnesses and run that ECU (aka wrx swap, etc).

The only way I can think this would be a simple swap for you, would be if you made the EJ207 block have the same compression (or maybe slightly more) than the stock EJ22E, so it can run off the EJ22 ECU, (not turboing it) and then what would be the point? just keep your stock engine.

[bd96]

I was thinking EJ257 + EJ25D heads and intake with emanage ultimate running the tune. Or I could just throw in EJ22T bottom end parts (rebuilt of course) and port the ej22e heads. Thoughts?

[StatGSR]

22E heads just don't flow ported or not, 257+25D would be a far superior setup even without any headwork.

[elislider]

And even better than that would be some EJ20K heads!

[lord flashheart]

22E heads just don't flow ported or not, 257+25D would be a far superior setup even without any headwork.

1 up on that!!
those 22 heads really suck ass.

[Reuben]

Don't forget EJ20R heads btw gents, they are near as makes no difference identical to 20K heads. They essentially are the same heads, and cams, only 20R is shim over, rather than under, has an extra hole drilled in the back of the left head, and WAY easier/cheaper to find!

You guy's have me thinking now... I want to chuck some 20R heads on a 2.2L I found... I'm converting the BC to a MPFI 2.2, but i've had ideas of superchargers..

After the disussion of 25D heads actually being fairly suitable for a 2.2 (thought it was just as unsuitable as they are on a 2L), i'll probably go with that though, they are a dime a f*ing dozen down here in QT.