2.5 block with 2.2 heads

[92ss satinsvoice]

Hi all,


im in the process of fixing my brothers motor outh of his 01 2.5rs. we were driving down the freeway when the timing belt tensionor bolt takes a fat dump and the belt slips. 3 exhaust valves got bent in all which is suprising out of 16. so we have a couple of options on the table.


FIRST!
replace the bent valves, check the valve seats and replace the valve stem seals for fun. weeee!!!

SECOND!

buy a set of 98 or newer 2.2 phase 2 heads for a little added power. I have read up on this option and it sounds pretty good. 9.7 -1 compression is stock. possiblity of having around 10.7-1 with the 2.2 heads.
no need to buy newer upgraded fuel injectors or engine management. because the amount in change to the compression is not enough to make the ECU flip out. just have to run mid grade fuel or better.

now fill me with your knowledge!!!

what ya think?

[subaru_styles]

pretty sure its 99+ for the phaseII 2.2's.

doesn't seem like a bad idea, but i would suggest porting the heads and getting cams

[92ss satinsvoice]

you know i think you might be right on that. i need to check out the bolt pattern on the stock 2.5 heads and the 99 heads.

[MConte05]

Stick with the 2.5 heads. They flow much better than the 2.2. The point of a 2.2/2.5 hybrid is for those who can't get the 2.5 heads to run with their stock ECU. It's a cheap solution. The 2.5 engine as a whole is better.

[mike-tracy]

I agree with using 2.5 heads if you can find them or economically repair yours. Otherwise swap the 2.5 cams into the 2.2 phase 2 heads for a bump in performance.

[entirelyturbo]

Mike is right. From some of the info I've gleaned when I was thinking about doing this, you'll make just as much, if not more, power getting some headwork done to your 2.5 heads as you would with the 2.2 heads.

It'll be safer too... depending on what headgaskets you use, you could even be up to 11:1 CR and you would have to run high-test, and still be at risk for detonation.

The EJ25Ds and EJ251s have gotten a poorer reputation than they deserve because of the headgasket issues. Replace them with the new, updated MLS gaskets and they're still good engines.


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[92ss satinsvoice]

looks like we are just going to try and fix the 2.5 heads. from the looks of it theres only three bent valves which are $12 a peice. i'll rip the heads down and check the other vlaves just to make sure.


I wonder what delta would charge for a set of SOHC regrinds. isn't it around $220 for the set?

[MConte05]

Way cheaper than that.

[Someperson]

is the 2.5 just better than the 2.2 or?

[entirelyturbo]

Not better, it's just that increasing naturally-aspirated power is easier with the 2.5.





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[northcoast]

I wonder what delta would charge for a set of SOHC regrinds. isn't it around $220 for the set?

Sounds about right but give Ken a call on Monday and ask him yourself. He's a super cool dude and knows his Subarus.

[Baddog]

My buddy with his 98 LGT vs my Frankenmotor 96 Legacy (both 5 speeds).

I have cams and a UEL header. Hybrid intake. Thats about it for anything other than the Frankenmotor.

He has a EJ25D with a UEL header. Hybrid intake. Intake Spacers.

I pull him off the line and all the way to 4th gear. And this is without my EL header, CAI, Spacers, 550CC, Whalbro 255lph and Megasquirt.

There is power to be had with either motor however. The problem with the 2.2 is no top end