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Old 02-20-2019, 02:43 AM   #1
Scooby Newbie
Member#: 450499
Join Date: Jul 2016
Location: oklahoma
2015 wrx
black and gray

Default FA20DIT forged internals build

https://imgur.com/a/fQ1kQgN"]First set of pics
More pics


I drive my car for Uber, and I show off a lot. When you do that you tend to break a lot of crap and I'm used to it. I have been thru 2 clutches, 1 motor (warranty), 1 rear end,1 clutch master and 1 radiator since I bought the car. About 2 months ago my car started ticking, and I stopped and had it towed home. Once I got the motor out and verified it wasn't the transmission or clutch I knew it was a spun bearing or thrust bearings. Thank goodness it happened close to tax return season since I didn't even want to bother with fighting another Subaru claim. This time I was going to fix it myself and I wanted the best most reliable deal I could get. My options did not look good.

Used unknown condition motor from eBay $2.5k to $3.5k
IAG block $3,999 + labor
salvage yard motor $3k
dealership rebuild $7k
Copart wrecked donor car $4k+ minus whatever I could part out.(2015+ WRX's are hard to find in my states Copart auctions)
wreck the car and buy a CTS-V (too much of a * to do it)
So I embarked on the quest of building a reliable FA20DIT that cost less than $3k-4k that would withstand my ****ty driving habits and abuse. Getting a zero mile forged motor for the price of a used one and cheaper than a IAG pre-built block sounded good to me. lets get started.

Shopping for deals
Here is my current parts list with retail prices and what I paid for them:
Excel spreadsheet

I had about one month to shop around and send emails to different company's to make sure I got the best price, and I kept all the info on this excel sheet to keep track of everything. OEM parts were the hardest to find deals on but my local dealership has the cheapest online prices i can find even though i have to pay sales tax. I'm still waiting on a quote from Maperformance on OEM parts to see if they can beat my current prices. Turn in concepts really helped me understand what i was about to get into and gave me some great advice on another post i made
Originally Posted by Turn in Concepts View Post
I've done a fair number of these now and I'll give you my thoughts. Let me break it down a bit as there's a number of things here to cover.

1) I have used both the BC and Manley rods. They have both worked fine. If time allows there's soon to be another offering on the market that I believe will be quite appealing to people in terms of weight, design, strength and price point.

2) If you are going to reuse your old case then you absolutely will need to machine for the pistons. Period. Anybody that tells you that you can use drop in pistons in a used Subaru case is an idiot. Your machinist is spot on with his recommendation. On a side note please make sure he does the machine work using a proper torque plate, AND using the hardware you're going to use for the build (in other words head studs due to your mentioning it).

Additionally, if you are reusing your old case I will strongly recommend you have the bore and straightness of the mains checked.

Bottom line a Subaru case is a floppy bag of aluminum that holds the guts in. With heat cycles it moves all over the place. You need to start with something that is true and square.

3) I have used the Manley pistons a number of times in a number of builds for a number of makes and models for a number of years. These will work just fine for your build.

4) I have used the king bearings on these engines. I have also used the ACL rod bearings (mains will be available beginning of march). The king rod bearings are fine. I do not like the main bearings. When they first came out we found that the main bearing clearance was HUGE. So we did the .001" tighter bearings. Still too big. The FA motor runs pretty tight bearing clearances. A call to our rep at King, and we found that they made the .001" tighter bearings the same thickness as standard. So the king standard is .001" bigger than OEM standard, and the STDX (big clearance) is actually .002" bigger than OEM standard.

Now, I can understand why they did this because when people do aftermarket they usually go bigger. In many cases this holds true, but in the case of the FA20 this is not the case.

Granted this was a long time ago so they may have changed that up, but I am just relaying my experience.

So, we have been using the OEM main bearings to get our target clearances. I want to emphasize something for everyone out there, beit the FA or the EJ engine. The Subaru OEM bearings are GOOD bearings. There's not a darn thing wrong with them from a technical standpoint. What people do not like is the price, and the FA main bearings is no exception. Compared to the aftermarket they are quite expensive, BUT in the FA market as of right now you don't have a choice (that I am aware of) if you want to hit your target clearances... or perhaps I should say my target clearances.

5) The Subaru master gasket set is not complete. A number of items are missing such as the stuff you need for the heads. Please keep this in mind.

6) Speaking of heads. As long as it's apart you will want to get the heads refreshed. I will caution you - the MAXIMUM you can deck of these heads is .004". That's not much room. If you need more then you can get thicker head gaskets from the boys over at Outfront Motorsports.

Also in regard to the heads - it has recently come to light that the OEM exhaust valves are currently the best possible valve for this motor. They are an inconel sodium filled valve, and is currently the apex of valve technology. The aftermarket has not caught up in this case yet. These engines run a rather hot combustion and the exhaust valves get scorching hot. Currently anything from the aftermarket has been failing to a degree that I am not happy with.

7) If it was a bearing that failed in the old engine then you MUST disassemble and clean every single oil passage. You MUST take apart the oil pump assembly and inspect it for scoring. You MUST take your old oil cooler and throw it in the trash and replace it.

8) ARP head studs. They do not have a bullnose on them. They do not have a neck between the threads. What happens when you install these is they "bottom out" on the threads. Because of this you MUST MUST MUST install these by hand, and DO NOT crank down on them with the might of Thor. Follow the instructions absolutely perfectly that is included with the kit. Personally I do not think they are as well engineered as the EJ studs. Yes. They work. Yes. They are (currently) the only game in town for FA studs.

Anybody that wants to argue with me in regards to these studs I will fight you, and you know my address. I have spent countless hours measuring and researching the head studs for the Subaru engines. Why would I do this? For a good reason. Perhaps I'll be able to elaborate on exactly why in a few months time.

And FINALLY the conclusion to my essay/rant. It sounds like you are heading down the right path, and it sounds like you machinist has a good head on his shoulders given his advice. Do continue, BUT keep in mind that there WILL be things that come up so please keep this in mind when budgeting.
The labor
I'm a decent mechanic, but I have never rebuilt a motor, so I decided to go with a local Subaru enthusiast shop that gave me a hell of a quote on labor and is letting me help with tear-down and rebuild to reduce the cost further. I live in Oklahoma, so my shop cost will be different from other states so I won't bother with posting that. Removing/installing the engine is simple so I will do it myself to cut down the labor cost.

The tear-down
The FA20 is a lot different from all the EJ motor tear-down videos I have seen. There are no wrist pin removal holes in the block so its kind of awkward to get the case half's to split. I recommend leaving your engine on the stand and loosening the rod cap bolts first, before removing the case half's bolts. Once you do that take all the caps off and split the case. Everything else was simple and self-explanatory.

Once I got everything apart, we started the inspection. We found one spun rod bearing(doesn't look like it damaged the crank); the front thrust bearing was shot(no damage to the case or crank), but the thing I didn't expect was my cams and cam journals to be scorn. We plan to send them to the machine shop to see if they are salvageable if not I'm going to need to buy new ones. I didn't think I would be making a post so i didn't take pics of the damage but i will stop by the shop and take some tomorrow and add another imgur link to the top

I am sending the case half's, heads, cams, front cover(oil pump), upper/lower oil pan and crank to get cleaned
The case is going to get honed .1mm over, and the main's will be line honed.
The crank is going to be checked to see if it's reusable since I can't see any visible damage on it. I have already bought a new one, but if I can reuse my old one, I will return it and spend the $460 elsewhere. The cam's and heads are also going to be checked for usability plus a port and polish
Estimate cost $300
Actual cost Coming soon...

Coming soon...

Leo Vishnyak over @Maperformance is helping me with a partial Sponsorship, so I wanted to thank him for that opportunity. I wish I would have asked for it sooner since I already bought all my aftermarket parts but this build is far from done, and I look forward with working with him and keeping you guys updated.
This is my first ever in depth post on a forum so I'm sorry if the format is all messed up and for grammar/spelling stuff, I'm a aircraft mechanic not a writer/blogger
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Last edited by dreew; 02-20-2019 at 01:58 PM. Reason: added pics
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Old 02-20-2019, 10:07 AM   #2
Member#: 141043
Join Date: Feb 2007
Chapter/Region: MWSOC
Location: Cottage Grove, MN
2011 STI
black af


Happy to have been a part of it sir! Please keep me posted if you ever have a need for anything else!

Leo @ Map
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Old 02-27-2019, 08:18 PM   #3
NASIOC Supporter
Member#: 443842
Join Date: Apr 2016
Chapter/Region: Tri-State
Location: Long Island NY
2015 WRX Premium
WR Blue Pearl


Nice I just re did mine check my thread out here. Wasn’t too bad. I listed everything I used in my build. Went a slightly different route. Mic’d It all up set everything the way I wanted it and it’s been running great

I’m pulling my friends engine out, his FA I beilive spun a rod. When I split the one apart I’m going to take tons of pictures. Mine suffered from ring land failure I posted pics on the thread
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