@DannyP posted:Phil, don't you have different cam(s) in there too?
And you're right, the Suby even at it's 10.3:1(I think) compression ratio runs great on 87 octane. If the CR is raised then premium is necessary. I think compression is 11.5:1 using the SOHC head gasket. The DOHC gasket is thicker which gives the 10.3:1 ratio.
With 11.5:1 on 93 octane with 2.5 liters of free-breathing massaged heads? Sounds like 200hp to me!
EDIT: I believe the numbers I quoted were hot-rodded numbers from the NASIOC website. I think the stock EJ25 is somewhere from 9.7:1 to 10:1.
Agreed.
I'm pretty sure that even with free-breathing heads, an N/A DOHC flat 4 can can't make 200 hp without bigger cam(s), and I'd almost bet that with those cam longer duration (longer overlap) cams and water cooling, 11.5:1 or even 12:1 would be entirely safe and possible. The Subaru bottom end fixes all the Type 1 weak spots and will very easily spin up to 7000 RPM without a lot of drama.
It's hard to see how an engine with more displacement, better cooling, and 4-valve heads wouldn't make at least as much power as a "200 hp" Type 1.