Project was going to be a 2.1L Stroker build, however I have pivoted to a more simplistic build: Forged 2.0L.
(Note: This page will be continuously updated as I make progress on my engine build. Check back occasionally for the latest updates.)
Sections (Click to jump to each section):
2.0 Getting the bones for the build
1.0 Start
I have wanted to build an engine for many years, and I figured it was about time I get started on it. I currently own a silver 2002 Subaru WRX, which comes from the factory with All-Wheel Drive, a manual 5-speed transmission, and a 2.0L turbocharged engine, putting out 227 hP and 217 lb-ft of torque. Curb weight is just under 3,100 lbs. The car still runs, and I use it as my daily-driver. My goal is to have some fun with building an engine for it, getting the power up to about 300-350 hP at the wheels. I also plan to allow my kiddos to wrench on the build here and there, as I learn how to build an engine myself. (Top)
2.0 Getting the bones for the build
Months ago, I found a motor for sale on Craigslist. I picked it up for about $500. The heads look clean (from what a rookie like myself can tell), and the block has some corrosion inside one of the cylinder walls, along with what looks like some damage in another cylinder at the top edge, that interfaces with the head. This is the motor I will rebuild, and swap into my car once it is fully built up. Images below:
3.0 The Teardown
(June 2021) The teardown is complete. The pistons have been removed, and the halves have been separated. The funnest part was removing the pistons, and my kiddos were able to help with this part, tapping the piston pins out to free the pistons for removal. Maybe they will appreciate that someday, haha. The most difficult parts were removing the crankshaft sprocket (for the timing belt), and separating the engine block halves. I bought a pulley puller tool to remove the sprocket, and it made simple work of it. For the engine block splitting, I used the factory jack from the trunk of my car and hand cranked it to pop the sealant from the halves, and finessed the rest of it apart with some wooden shims, a bit of shouting/yelling, and about 2-hours of finessing it apart.
4.0 Visit to the machine shop
I called up a local machine shop and asked if they worked on Subaru engines. Turns out, one of the machinists is a Subaru owner himself, and he offered to help me out. After the initial phone call, I drove over to the shop with my engine block and heads. The machinist let me know that the heads were still good, and he could get them cleaned up. Unfortunately the block was not useable, as there was too much rust/corrosion/galling at one of the cylinder sleeves. Time to go find another short block.
<INSERT PHOTO OF BAD CYLINDER HERE>
Luckily, I have a really good friend who lives on the West Coast, and he has built his fair share of Subaru engines and happened to have a few (an understatement) extra parts laying around. He was kind enough to ship a pallet of parts over to me here in Arizona for an undisclosed amount, and man am I grateful. Within the pallet of parts were two engine blocks (aka short blocks), some brand new OEM bearings and piston rings, a crankshaft, some pulley/cam gears, gaskets, bolts, and some other goodies. I’ll mention his name and company after I get his permission, but for now let’s keep his name anonymous and call him Phil, short for “philanthropist.”
September 12, 2022 was my 2nd visit to the machine shop, this time where I dropped off the following parts for machining:
- LH and RH heads with camshafts, springs, valves, and related parts installed
- LH and RH short block halves, newly obtained from Phil
- Crankshaft, newly obtained from Phil
The heads will be gone through and a price estimated on the amount of work that needs to be done. The block will be a simple bead-blast, bore, hone, and deck with a torque plate. Shop asked if I was going to use ARP head studs, in which I will most likely use, in place of the OEM bolts. Shop says they will need the studs if I plan to go this route, in order to get the proper torque plate setup. Tribal knowledge says to use a torque plate because it simulates the head being attached, which creates slight distortions to the block. Machine with distortions active (aka: torque plate), and your precision of up/down movements of pistons (which already has clearance built-in, and is taken up by piston rings) gets incrementally that much better. The crankshaft will be inspected and polished.
Questions I have so far:
- Will I use ARP Head Studs?
- What forged pistons will I use? Shop says to buy pistons now, and get the +.25mm diameter size. Options are Wiseco, Mahle (pronounced: Mall-E), JE, etc.
- What forged rods will I use?
- Do I need to get the crankshaft balanced?
Useful resources:
- NASIOC forums
- Subaru ONLY YouTube videos: https://www.youtube.com/c/SubaruONLY
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