Hey everyone, recently my 2010 STi took a poop on me. Had some misfiring, put in new spark plugs, continued misfiring. Did a leakdown test and got 80% leak on cyl. 2 and 40$ on cyl. 1. I was convinced it was ringlands, so I pulled out the engine in my driveway and brought it over to my friend's shop. We fully disassembled the engine, and behold, piston #2.
Piston #1 had one chunk of ringland easily come out as well, and #3 had a few hairline cracks and a chunk missing, and #4 had just a small piece broken.
I am now on the quest to rebuild the shortblock. I'm aiming for durability. I know everything will break at some point, especially with modified engines, but at this point I'd rather have more durability than power. I only had an intake, downpipe and exhaust and a dyno tune, with 330whp on the shop's Mustang dyno. I don't plan on making over 400whp anytime soon, but will eventually. I want my block to be as reliable as possible, while still making decent power.
I've done a lot of research, and it seems rather expensive to buy a Cosworth short block, which was what I was considering. Does anyone know if you can send them your shortblock to avoid a core charge? My block is still in great shape (only 24k miles) and I don't need a brand new one. I've also read that it would seem to behoove me to have my block built by the same person that will be tuning it, that also provides a warranty, so their won't be any blame being passed around if and when it does break. So that brings me to another question, are there any reputable tuners/engine builders near the Philadelphia/Tri-State area? I'd rather not have my car need to go 5+ hours away to be tuned, unless this tuner/engine builder is godlike with Subaru motors.
If I supply the parts and have someone build it or doing myself, I was thinking Cosworth pistons, and definitely Manley Turbotuff Rods. Probably Manley bearings as well. That's what I'm doing at the minimum, unless there are some other parts I can swap into the shortblock to increase durability. Also keep in mind this will be my dailydriver, however I don't mind if it's "not comfortable to DD" (I'm most likely doing a stage 4 six puck clutch).
I'm not really looking for a specific power number; I was comfortable with the power it was making when it broke. I just want it to be more durable, and be able to handle the power when I do some more things to it down the road. Thoughts?