What's the piston dish on the NA EJ22?

[Matt Monson]

My pee-wee brain has been at it again and I have a new Frankenstein engine idea, but need some help calculating the CR.
I am thinking of taking my 1990 NA EJ22 and putting on some EJ25 heads (DOHC or SOHC to be determined). I figure that this should net me a CR in the 8.5:1 to 8.8:1 range. Then I slap on my VF-28, Sti yellow injectors, run around 15psi of boost and see what happens. I figure I could have a 300hp engine on my hands with decent reliability. We all know the old EJ22's are better made than today's engines, and I can't figure it is any weaker than the USDM EJ205 that guys are getting that kind of power. And it would be in a project car, so if it blows up, so what...

p.s. I am casually shopping for the car(can't buy until other project is sold) if someone has one for sale. Any Legacy sport w/ a blown engine preferred, but NA 5 spds will also be considered. I am looking to spend $500-1000 for the car...

[TDGKORN]

I decided i'm going to sell mine, if you are still interested.

I've been offered $1150 for it from j-money.

Let me know if you still want it.

Troy

[Matt Monson]

He's looking right now and has been looking for a few weeks. Sell it to him. I am at least 2-3 weeks off from having the cash. I am waiting for a part from Japan...

[evolutionmovement]

My good ruler is at work. I can get this for you tomorrow night, but there are small indents for the valves, too. That you'll have to consider negligible or ... I don't know. I'm not casting it in molding compound to get it's displacement.

Steve

[Matt Monson]

Steve,
Just your basic guesstimate would be awesome. I am just looking for a ballpark CR as a starting point to see whether or not this is even a viable option. I want to be the guy they are talking about when they say," They said it couldn't be done, so he did it!" It would just be fun for a while to have a homemade EJ22-T powered Legacy that eats WRX's...

[greg donovan]

try ejcalcs:

http://wac.addr.com/auto/obs/turbo/ejcalcs.html

not sure of the accuracy but it looks like the piston volume for the na ej22 is:

14.5cc on a 90 ej22 piston from another site he quoted

and

12cc on a 97 ej22 that he claims to have gotten through actual measurement.

i used this site to calculate CR:

http://www.kb-silvolite.com/calc.php?ac ... a39409fc71

this site was very usefull too:

http://www.sciencemadesimple.com/conversions.html

[evolutionmovement]

There's an irregular surround of metal around the dges, but the center dish is about .055 (a guess as I forgot my ruler) with four semi circle indents for valve clearance. Dammit! I need a graduated cylinder.

Steve

[Matt Monson]

Ok,
I ran the numbers and I am looking at 8.4:1 CR if I used the EJ25 SOHC heads. Thanks guys...