rebuild advice on 06 WRX

[taco15]

Might be doing a rebuild on my 06 WRX with 60k miles.
It seems I may have some money free up after I part out crx and would like to get the opinion and advice from previous builds and experience people here.


My issue started when Oil starting coming out of the BOV. I had the oil changed with oem stuff here at my dealership and didn't realize it burned through the entire quarts in 2k miles! So i topped it off hoping it didn't damage anything. once month later after installing an AOS it started smoking at startup and then it stopped doing it. I went ahead and did a compression test.
compression results

4- 120psi
2- 85 psi
1- 150psi
3- 160

needless to say I need new rings.

FAST FORWARD.
The build I have in mind is a moderate yet strong enough to hold more than enough.

Pistons to raise compression up a bit from stock (CP, Mahle please input info if you have a reason why NOT to go with these)
Eagle H beam rods since they are one of the most affordable and can handle the power. plus I've used the brand before with success.
Arp studs on head
Arp rod bolts

I just hope my crank is salvageable but since it's driving now i don't see why not.

misc - timing belt, larger oil pump,oil pickup, header and uppipe with turbo inlet also upgraded.

Turbo will come later once I do more research but everyone says a 20g would be enough for my power goals.
I'm shooting for a safe 350AWHP since breaking transmission or axles, major fuel upgrades etc isn't on my agenda.
May do some E85 since I have a pump 1 mile from my house and it looks like gas is going to get jacked up again.

The car is not going to see a track. Some occasional autocross once a month. It's going to be my daily driver so reliability is key. especially since I'm still making payments

my question to members is the realistic cost of building such engine. If all goes well I should have approx. $6,200 with $3,500 of that by tonight (crossing fingers).

[JAC Wagon]

I think all of that is very feasible. I have all the parts for my STi short block including Mehle forged pistons and all that only cost me $900. If you shop around and find used but good parts that will save a lot of money.

[HolyCrapItsFast]

You have more than enough money to do that

One thing I would consider changing is the head studs. Unless you are using the ARP L19 head studs, you are better off going with a new set of stock bolts. That would be more than enough for a 20G and power below 400WHP. The regular ARP studs are no better than stock and I have found that they tend to stretch and often require re-torquing. Also stock head gaskets FTW!

Chances are your crank is salvageable. Find yourself a good local machine shop and discuss your build with him. He will make recommendations on polishing or cutting. The best thing you can do for a successful build is to concentrate on proper machine work and oil clearance. For instance you want to determine the best size piston to use and your machinist can make recommendations based on the current condition of the motor. Then he can match the cylinder walls to the pistons you buy. Also request that he torque plate bore and hone. This will ensure proper piston to wall clearances and centricity when the heads are finally mated to the block.

If you plan on using E85 then you will need a fuel pump and larger injectors. If you are going with a 20G or larger turbo, and depending on how aggressive they tune, you may need 1000CC injectors

[JAC Wagon]

Holy, you are like the Subaru genius... no scratch that. Subaru God

[HolyCrapItsFast]

No not really... Just done this about a thousand times... Six of them on my own car

I think as far as builds go though Rek has me trumpped.

[taco15]

Does a 05 Sti block interchange with the wrx 2.5?

[JAC Wagon]

And the only difference between them is the piston head correct? The STi one is "bowled" where as the WRX (and Fozz) motor is flat piston heads right?

[Zach@TTLM]

Pistons to raise compression up a bit from stock (CP, Mahle please input info if you have a reason why NOT to go with these)
Eagle H beam rods since they are one of the most affordable and can handle the power. plus I've used the brand before with success.
Arp studs on head
Arp rod bolts

I just hope my crank is salvageable but since it's driving now i don't see why not.

misc - timing belt, larger oil pump,oil pickup, header and uppipe with turbo inlet also upgraded.

I am agreeing with holy on a lot of things...first of all, have used CP pistons in several builds and very happy with the results. Have seen even better results when pistons have been coated, may want to consider getting this done. Next Eagle H Beams come with ARP rod bolts, no need to purchase seperate. If doing ARP studs do the L19s. Also complete timing set don't just change the belt, Gates has a complete kit including water pump while doing this its a good idea. Far as the crank goes do as Holy said and talk over the build with your machine shop. See what they feel is needed and work with that let them grind and polish they make bearings for the undersized cranks for this reason. I recommend ACL Race Bearings. Anything else we can help with don't hesitate to ask!

[taco15]

My CRX is sold!!!!

I can get a full 05 Sti block with all internals from a friend.
it would be much easier to send it out and get it rebuilt while I can still drive my car. Once I have it back I can swap it all out and put the new block in.
As long as it's a direct bolt on I'm fine with it.

anything i should look for in difference?

[HolyCrapItsFast]

The WRX heads are different so going from the WRX block to the STi block just make sure you purchase the right head gasket. you need to make sure that the bore hole on the gasket matches the block and the port holes for the water jackets and oil passages match the head.

If you do a search on Google for "STi Hybrid Head gasket" you get some promising results. This was the first site that showed up.

http://www.flatironstuning.com/p-189...stall-kit.aspx