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There is still machining required even with an OEM block

you should still get it honed, and pistons fitted correctly. You can do manley drop ins but they are still pretty noisy.

line boring should be done on any block. regardless of new/used.
 

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Discussion Starter #22
Why would Subaru not fit the pistons correctly or line bore it when they assemble it?

By noise are you referring to piston slap? If so, how is that eliminated?
 

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because Subaru mass produces these cars on a factory scale. not every bearing is measured and fit to exact tolerance. Some builders have stated they've seen Factory OEM case halves that have never been ran have out of round main journals.

likely you will want to increase clearance over factory since the FSM for my 2012 states:

Rod clearance: .00007 to .0018
Main clearance: .00039 to .0012

These are tight for an engine that is going to be abused.

It depends on how the engine will be used on how you decide the clearances, but a "general" spec is .002 on rods and .0015 on mains.

Piston slap is due to increased piston-to-wall clearance. Subaru specs this at:
-0.00039 to .00039

If you just drop in forged pistons, you're PTW clearance will likely be .0025 to .0045 or worse. it will slap bad on cold start(ask me how i Know. my PTW clearance is .0025) and "can" eventually oval the bores causing oil consumption.

to remedy this, you get your pistons sized with the bores. by taking it out to 99.55mm or 99.75mm.
Stock cylinder diameter is:

A bore: 99.505 to 99.515
B bore: 99.495 to 99.505
 

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all why I suggested just buying an IAG short block - this is all done properly . . . but i'll be the first person to admit that buying isn't the same as the building experience . . . but perhaps building doesn't count unless you do the machining yourself . . . the point of that comment is to say evaluate and and understand what your limitations are and make a wise choice for yourself.
 
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all why I suggested just buying an IAG short block - this is all done properly . . . but i'll be the first person to admit that buying isn't the same as the building experience . . . but perhaps building doesn't count unless you do the machining yourself . . . the point of that comment is to say evaluate and and understand what your limitations are and make a wise choice for yourself.
you hope its done properly :)

The old adage is "if you want something done right, you have to do it yourself"
 

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Discussion Starter #26 (Edited)
I don't have the equipment to line bore the block.

So, the OEM Subaru short block from IAG is approx. $400 more than directly from subaru. With the cost of machining would it be more worth while to purchase the IAG OEM Block?

Does IAG do any machining to these OEM blocks? I don't see anything eludes to that on their website.
 

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no. From the definition those are just OEM blocks from Subaru.

A good starting point is just case halves. line boring isn't super expensive. my local shop charges 165 to line bore a block with 5 mains.
 

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So, the OEM Subaru short block from IAG is approx. $400 more than directly from subaru. With the cost of machining would it be more worth while to purchase the IAG OEM Block?

Does IAG do any machining to these OEM blocks? I don't see anything eludes to that on their website.

Where does IAG offer any stock short block - you can provide a link? Lowest I see is Stage 1 for $3K. The description is not as specific as I'd like but does include this statement:

"*All IAG short blocks are balanced and blueprinted."

Despite what has been related here, I didn't think they line bored new blocks because they felt they were good. One reason I didn't respond earlier. They definitely line bore used blocks and use new cranks when they rebuild one. Anyway you can ask em.

We have seen OEM for a good bit under $2K+shipping not that long ago . . . figure a $1k difference between stock and bottom end IAG. Only issue I have w IAG is that all their lower end blocks use 2618 pistons. I am out of date, but the really didn't want to let me use 4032. Now they offer something - at $5K? (Nope, it's gone again) That said my engines is strong after 40Kmi - and we have User as a benchmark . . .

Not sure what the OP was using for pricing.
 

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Buy a subscription to either alldatadiy.com for a subaru manual or get a subscription to STIS. Both of these sites have a ton of factory spec assembly info
 

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Discussion Starter #30
I'm gonna go look at an engine next week. Someone near me is selling a 2008 WRX engine with one of the heads still attached. He's only asking $350 for it.

Are there any obvious items I should look for like certain parts of the block snapped off from mistreatment? I'll take a metal ruler and some feeler gages with me. Also thought a breaker bar and sockets would be a good idea to ensure the engine is locked up from over-heating. Any other suggestions are welcome.
 

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check transmission to engine mounting bolts on the rear, a lot of times guys strip those cause they are messed up from the factory.
 

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Discussion Starter #32
Anybody know a good method for removing piston wrist pins that doesn't use the "special tool"?
 

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Discussion Starter #35
I pulled the trigger yesterday a bough a used short block with one head still attached. The seller said that the engine was from a WRX but the case halves are labeled AA and AB. So, does that mean that is was from an STI and not a WRX? The seller only bought it for the RH head.
 

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I pulled the trigger yesterday a bough a used short block with one head still attached. The seller said that the engine was from a WRX but the case halves are labeled AA and AB. So, does that mean that is was from an STI and not a WRX? The seller only bought it for the RH head.
It refers to the cylinder size so you can correctly clearance the PTW.

A: 99.505 — 99.515 mm (3.9175 — 3.9179 in)
B: 99.495 — 99.505 mm (3.9171 — 3.9175 in)

Sent from my SM-G955W using Tapatalk
 

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If it won't come out, do I get a bigger hammer?
Check to make sure the spring clip is out, or make sure you're tapping on the correct part. If both of those check out, maybe tap a little harder, but they should just start sliding out without having to get creative.

Sent from my SM-G955W using Tapatalk
 

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Discussion Starter #40
It refers to the cylinder size so you can correctly clearance the PTW.

A: 99.505 — 99.515 mm (3.9175 — 3.9179 in)
B: 99.495 — 99.505 mm (3.9171 — 3.9175 in)

Sent from my SM-G955W using Tapatalk
Correct. I was aware of the what the letters meant. For some reason I was under the impression that the WRX case halves used different lettering. It is a single AVCS engine. Could that be what makes it a WRX engine and not a STI engine?
 
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