swaping EJ20T heads on a EJ22t? what problems?

ej22t kid · Post by **ej22t kid** » Thu Jul 28, 2005 8:47 pm

i am looking to get a little more power out of my 91 legacy turbo, i have read most of the conversation about the RS heads but was told those would not work because they are none turbo. i live in cali and have a couple of JDM engine importers around and can buy a EJ20t for around 650. would it be better worth the RS or EJ20t heads?

tris91ricer · Post by **tris91ricer** » Thu Jul 28, 2005 9:13 pm

IIRC, Matt Monson recommends the NON-Turbo heads, EJ22E. Have you budgeted for that EJ20t, yet? If so, snag the 22E heads, and get some work done on 'em.

Matt Monson · Post by **Matt Monson** » Fri Jul 29, 2005 5:17 pm

Actually,
I think the Ej20G heads on an Ej22T would be a pretty potent combination. I sold mine to VRG for him to put on his car. And especially if you can get the complete engine with intake plumbing, AWIC, and if the engine came from a manual car the VF-8 turbo.

To do this swap, you would use the intake manifold from the EJ20G as well. Pretty much all the sensor connectors like IAC are the same. It should work pretty well on your stock ECU, but you will want to up the boost. the larger combustion chamber volume of the EJ20G heads will drop your CR to around 7.3:1 Not really a problem, but many people shy away from this because they think driveability will suck. This just isn't true.

The one custom piece to this swap would be mounting up your coil onto the manifold to use your stock ignition. But even that is pretty straightforward.

Lastly, using the RS heads is a decent option, but since they have no oil or coolant returns, a lot of custom work comes into play. The real beauty of the EJ20G heads is it really is a factory conversion...

tris91ricer · Post by **tris91ricer** » Fri Jul 29, 2005 7:14 pm

Looks like you got your answer, and I've got my facts straightened out. It's allllll good.

Project_Legacy · Post by **Project_Legacy** » Tue Aug 02, 2005 3:42 am

sounds sweet. most likely my next project. when i get some damn moneys.

morgie · Post by **morgie** » Wed Aug 03, 2005 12:27 am

ej20G heads don,t have the same volume than ej20k-5-7 .. something like 46cc vs 49cc. that's little but that may be important.

Project_Legacy · Post by **Project_Legacy** » Wed Aug 03, 2005 9:49 am

ej20g heads are easier and cheaper to get though arent they?

Matt Monson · Post by **Matt Monson** » Wed Aug 03, 2005 11:14 pm

Morgie,

Ej20G heads have a combustion chamber volume of 57cc. They are a fair bit larger than the EJ205, etc because of the old valvetrain design. They valves were tilted at a significantly wider angle than the vavles on other Subaru engines, and as such, they got more head volume.

Thank you for catching my error above. I said 7.3:1, that's for Ej25 heads. The EJ20G heads are going to put you at 6.8:1...

Natoe · Post by **Natoe** » Thu Aug 04, 2005 12:37 am

so for a cheaper alternative, the EJ22E heads are good as well? and there isnt a problem with coolant and oil lines?
sorry for my lack of knowledge but the EJ22E is all impreza and legacy NA 2.2L's?
thanks

Matt Monson · Post by **Matt Monson** » Thu Aug 04, 2005 5:41 pm

Nope,
There are no coolant or oil lines. The Ej22E heads just have a bigger valve size, but you would have to deal with coolant and oil for your turbo...

Legacy294 · Post by **Legacy294** » Fri Aug 05, 2005 12:01 am

DOHC heads will work, but as mentioned previously, match the intake and heads accordingly. Going with any of the SOHCs would be more of a lateral manuver..

That set up is going into my rally car, ala 22B..

Legacy294 · Post by **Legacy294** » Fri Aug 05, 2005 12:07 am

Matt,

since you seem to be sharp on the C/R equations, what would an N/A EJ22 w/ DOHC 2.5 RS heads end up with? We are contemplating that set up on a 2.5RS gone wrong..

My buddy (excellent engine builder) seems to think that the CR will be WAY too high and detonate like hell due to the flat top pistons in the 2.2NA.. what do you think? Have you built one?

Matt Monson · Post by **Matt Monson** » Fri Aug 05, 2005 12:07 am

Legacy294 wrote:DOHC heads will work, but as mentioned previously, match the intake and heads accordingly. Going with any of the SOHCs would be more of a lateral manuver..

That set up is going into my rally car, ala 22B..

I hope you aren't including EJ25 SOHC heads in that comment. The Ej25 SOHC heads are superior to both DOHC EJ205 and Ej25 heads...

Matt Monson · Post by **Matt Monson** » Fri Aug 05, 2005 12:10 am

Legacy294 wrote:Matt,

since you seem to be sharp on the C/R equations, what would an N/A EJ22 w/ DOHC 2.5 RS heads end up with? We are contemplating that set up on a 2.5RS gone wrong.. My buddy (excellent engine builder) seems to think that the CR will be WAY too high and detonate like hell due to the flat top pistons in the 2.2NA.. what do you think? Have you built one?

Actually, if I read you right, your buddy has it backwards. The Ej25 heads have more volume than the Ej22 heads. You hit a very boost friendly 8.6:1 with that combination. I have one of these ready to assemble in my garage. I just need a gineau pig to let me put it in their car and see how much boost it takes to blow it up...

PeteGLH · Post by **PeteGLH** » Fri Aug 12, 2005 10:56 pm

If I read correctly, EJ20G Heads would require a matching Intake manifold?

Would my stock Ej22T Exhaust headers bolt-up to the EJ20G heads?

Project_Legacy · Post by **Project_Legacy** » Fri Aug 12, 2005 11:01 pm

i believe it should. i could check though.

vrg3 · Post by **vrg3** » Sat Aug 13, 2005 2:13 am

That's correct, Pete. And yes, they would.

Post by **Legacy777** » Sat Aug 13, 2005 5:21 am

PeteGLH wrote:If I read correctly, EJ20G Heads would require a matching Intake manifold?

Would my stock Ej22T Exhaust headers bolt-up to the EJ20G heads?

yes on both counts

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swaping EJ20T heads on a EJ22t? what problems?

swaping EJ20T heads on a EJ22t? what problems?

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