EJ22 High compression thoughts and ideas.

[superu]

So I understand the EJ25 block with EJ22 heads is the Frankenmotor high compression setup.

But I was thinking, is there a high compression setup based on the EJ22?
I originally had this though regarding the old EA82's 1800 cc motor, but that would probably be problematic, switching generations, so then the EJ20 block came to mind when researching other setups, mainly from Australia, where they've been running NA EJ20s forever.

So, I guess there would be differences with SOHC vs DOHC pending on heads, but would EJ20 heads bolt onto an EJ22 and be a good HC setup for an EJ22?

But what are people's thoughs, experiences and ideas about bolting EJ20 heads onto an EJ22 to get an HC NA EJ22 setup?

[StatGSR]

Pretty sure ej20 heads would decrease the compression on a 2.2 (i think the combustion chamber volume on a ej20 is larger than that of the 2.2). Also keep in mind that in general you need to use the matching intake manifold for the heads you use, which often times means different sensors (or location) and substantial wiring work.

ej18 heads may bump up the compression, but will flow even worse that 2.2 heads, so there is no point in doing that.

[superu]

Pretty sure ej20 heads would decrease the compression on a 2.2 (i think the combustion chamber volume on a ej20 is larger than that of the 2.2).
ej18 heads may bump up the compression, but will flow even worse that 2.2 heads, so there is no point in doing that.

Hmm, I didn't know that. And the ariflow nd intake makes sens, also knocking the EA18 idea further afield.

But that's interesting what you say about 2.0's having a larger combustion volume. Is it a longer stroke or that 2.0 heads have more compression volume b/t the top of the piston stroke and the valves? What gives a 2.0 a larger volume?

thanks for good info!

[StatGSR]

See this for an example of the CC volume
http://www.merkurxr4ti.com/chambervolume.html

The CC volume isn't necessarily smaller just because an engine displacement is smaller. I'm sure there are many factors that come into play when the CC is designed. some of those would include, the overall engine compression ratio, piston to valve clearance, overall head flow, valve size, cylinder bore, as well as design considerations for creating a complete fuel burn.

when you swap, heads the only thing you are doing to change the CR is changing the CC volume (or maybe headgasket thickness), so to increase your CR you would have to decrease your CC volume. I'm not sure if there are any heads that you can put on a na 2.2 to increase the CR. IMHO you would be better off with some delta cams and some port and polish work if you were determined to keep a 2.2 but wanted a little more out of it.


***EDIT

doesn't look like the EJ18 EJ22 Hybrid ends well, the CC may be a little too small and apparently the ports and valves are just way to tiny.
http://www.rs25.com/forums/f5/85442-ej2 ... ons-2.html (http://www.rs25.com/forums/f5/85442-ej22e-ej18-hybrid-questions-2.html)
http://bbs.legacycentral.org/viewtopic. ... &view=next (http://bbs.legacycentral.org/viewtopic.php?t=15368&view=next)