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could jdm ej20t heads be put on our ej22t's? im talking about heads of a jdm legacy turbo if that helps. im thinking about buying the entire engine to swap parts over. what about internals? the seller says they are the same as STI internals. what do you think? what engine do you think has more potential? a jdm ej20t or our ej22t's? how much better is it to have a DOHC?
thanks, Teague

How much are you going to be buying the engine for?

I would say to just put your SOHC heads through a multi-angle valve job, and while you're at it, change the valves, springs, and retainers. This will end up allowing you to run a higher redline and have heads that will flow better than the DOHC heads in stock form.

Also, it would be better to buildup your 2.2L block. The internals of the ej20 would be similar, with the only difference being the displacement, and possibly the pistons. But again, while you have your engine apart, you might as well upgrade those.

FWIW, there's that old saying "there's no replacement for displacement." As you'll see with a lot of the wrx guys who want some bigger power, they'll end up stroking their engines to 2.2 or more liters. Something to think about.

the engine only costs $650, seems like a damn good deal. its a turbo legacy engine not a wrx engine. what i like is the seller lives less than a 2 hours drive from me so no paying shipping.

what 'n' a who now about the heads? how much would all that stuff cost?

just wondering if i could bolt the jdm heads right on, since i've heard they flow quite well.

the engine comes with the air water ic setup im pretty sure, and an auto transmission which i would probly sell.
thanks, Teague

So.. why dont you swap the whole thing in?

PS.
If there is anyone in Calgary area with a 2.2 block with out heads, we can try this as I have the heads sitting in a garage.

Mark

Doesn't the EJ20 have a slightly smaller bore than the EJ22? Couldn't that kind of screw up the shape of the combusion chamber if EJ20 heads were put on an EJ22 block?

One thing I do know is that putting the EJ20 heads on a EJ25 dropped the compression ratio to approx 6.5-7 to 1 and a person could have probably have outrun the car in the 1/4 mile on foot. We figured the hp at about 125hp.
AL(CO)
al@iwtu.net

I think vrg3 might be right. The ej22 block might be a bored out 2.0L which means the head area won't match the cylinder in the block.

so DOHC EJ25 heads are still the best way to go ? I'm sure the guys at cobb could put something together for us if we asked them real nice and put in for a group buy.

-IggDawg

Well, the EJ25 actually has a larger bore than the EJ22, so it still messes up the combustion chamber geometry some. The other disadvantage of the EJ25 heads is that they have cams tuned for naturally aspirated EJ25s, but Cobb wouldn't have a problem fixing that...

I dunno; I think boostjunkie's suggestion of putting the resources towards improving the flow of the EJ22T heads makes more sense to me.

vrg3 wrote: I dunno; I think boostjunkie's suggestion of putting the resources towards improving the flow of the EJ22T heads makes more sense to me.

his car is fast. I won;t argue with his logic .

-IggDawg

Thanks Igg, although I still have much to learn about these cars

FWIW, there's still the turbo legacy in the junkyard near me with some EJ22T heads on it. Anyone local could easily take those heads and have them re-worked while you drive on the stockers . . . then you can sell off the stockers so that someone else can re-work a set . . . kinda like a chainletter for head re-working . . .

I could be the first in this line of head buildups, since I do live closest to the heads . . . anyone else wanna participate?

The EJ22 heads actually have a larger static volume then the EJ25 heads. Don't know where the EJ20 heads fall in the pot.

I'd suggest you do some reading on what larry witherspoon discovered about trying to swap the EJ25 heads onto his EJ22T. The write-up is on dave's site.

6.5-7 to 1 compression! and only 125hp = Not enough boost.
As for the "no replacement.....crap, I have one thing to say.
MORE BOOST

Too bad more boost + bigger displacement = MUCH MUCH BETTAR!!

Yeah. I remember reading that list of turbos and what CFM they flow at what boost. and the fun little inserts saying "a 2.0 litre engine would have to be running 40 PSi to get this flow through this turbo" whilst on a 2.2 it was something more like 20 PSi. Once you start getting really up there, the extra .2 helps.

One thing the WRX has on us tho is the 8.5:1 pistons. how much does that really help compared to our 8:1 pistons?

(sorry for the hijack)

An 8.5 to 1 CR will help a little bit with off boost power, however, there are some drawbacks. I don't remember the specifics but I know the benefits of a high CR will be completely nullified when adding an additional 1psi of boost!!

Once you start really modifying for higher boost, I'd probably go with an 8 to 1 as it affords you a little more margin of safety, however, with lower boost pressures (under 20psi), I would like to have something like a 9 to 1 CR for better off-boost response.

well then. I guess I have no excuse for not going up to 20 PSI . now all I need are bigger injectors, fuel pump, IC, management..... re-worked heads .

good to know tho. that's sorta what I figured. with only 2 litres, the WRX must be horrible at 8:1.

IggDawg wrote:with only 2 litres, the WRX must be horrible at 8:1.

That's what I keep hearing from those guys . . . hence the influx of guys looking for 2.2 and 2.5L blocks . . .

I'm sure the whole "closed deck" thing is appealing too since they're basically running off the turbo and not the pistons

A low compression ratio makes it easier to stably run high boost without detonation, but makes the engine really sluggish off boost. If taken to an extreme, it can hurt turbo lag, too.

Some company/companies (Saab is one of them, I vaguely recall) are developing variable compression ratio engines. Or maybe they're already using them for all I know... sometimes my knowledge is outdated.

boostjunkie wrote:hence the influx of guys looking for 2.2 and 2.5L blocks

It will always hold true, now and forever more, there's no replacement for displacement.

vrg3, Saab gave up on the variable compression engine thing, too many problems. What a guy at a car show told me was that there were springs in the head bolts that would go up and down and therefore alter compression. It was a blown 1.5L 5cyl IIRC. capable of compression between 8.5:1 and 11:1 I think.

What I'd like to know is what went between the head and block when the head and block were pushed apart to lower compression...

I believe honda or some other auto manufacturer is working on a variable displacement engine.

The way it works is that the entire upper block portion pivots. Depending on the angle it's at, the compression ratio will change.