How to Build a Subaru EJ Engine that won't BLOW UP!

Time to dust off Project Bugeye WRX and start putting its new engine together. We'll show you all the parts that will be going into our EJ20 build, along with some of the tricks and processes we use to ensure its reliability. Many will say that a rebuilt EJ is never as good as one from the factory. We don't agree, so let's us show you how we do it.
0:00 EJ Build Intro
1:25 Cylinder Heads
3:23 Supertech Valves
5:45 Camshafts and Valve Springs
11:02 Engine Block Machining & Improvements
17:25 Eagle Long Rods
23:18 JE Pistons & Rings
28:05 Cryogenics
31:06 Eagle Stroker Crank
35:20 Fluidampr Crank Pulley
38:38 King Engine Bearings
43:43 Oiling Improvements
We have more content around our Bugeye project for all the Subie fans:
motoiq.com/category/projects/...
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[@Joshua5654]

Do I have an EJ engine? No Do I plan on building an EJ? No Did I enjoy watching the whole video? Yes

[@zacharyclarke4240]

I agree, pretty much every company makes a 2/2.2/2.4/2.5 liter engine that this applies to though

[@mikeylikesit2675]

In my instance it was Yes/Yes/Yes.

[@warboat1]

1. Yes x2 2. Yes x1 3. Yes x10

[@Darkhunter218]

I have an EJ205 with 7k miles on the rebuild feels good lol

[@neilquinn]

Ha, my last car with a Legacy GT with the EJ255 (2.5 turbo, same short block / heads / valvetrain as STI, just different turbo). Honestly I think the 2.5's were a step back from the 2.0s. This also looks like an insane amount of money and work just to hit 400-500hp when other manufacturers can get there stock (any chevy/ford engine, especially the LS), or more reliably, like the Honda K series with a turbo. I just wish Honda made better RWD/AWD options to pair.

[@grantschooling2911]

imagine Mike telling you, your motor blew up with a smile then goes on to explain for 45mins how he's going to rebuild it

[@kylesmith6515]

That's my dream 😂😂😂😂

[@djsonicc]

So basically every Subaru owner watching this video?

[@Nordlicht05]

After that the customer says I changed my mind bye

[@wa.gtrsoul]

@@Nordlicht05 and then watch as Mike's smile tapers off to a "Hide the Pain Harold"' smile.

[@rcatabay078]

I can’t even be mad at him regardless. I’ll be like, okay take my money 😅

[@mtraven23]

dude just casually dropping MOUNTAINS of knowledge. respect

[@djpenner34]

As an owner of multiple subarus and having rebuilt a few motors, this was the most informative, no bs ej video I've ever seen 👏

[@basik1dotcom]

Ditto!

[@CVBFonzP7B]

yup, gave me all the info i needed about rebuilding my shortblock

[@ROMSradio]

you'd think you'd learn and buy something reliable lol

[@truthandfreedom8145]

Do you need any special tools to get the job done ?

[@davidnetherway4734]

it's refreshing ain't it and so easy to understand

[@obxurv]

I think he's smiling because he's literally explaining probably 20 plus years of experience and all the expertise and knowledge he's acquired that its literally a joy to pass on the knowledge. It's like a teacher that actually enjoyed the subject they taught, all of us has had atleast 1.

[@hksoundpro]

So refreshing to hear someone who understands what he's talking about, explain things so clearly.

[@imnotsurewhy]

That's THE Mike Kojima for ya. A LEGEND in the community.

[@nickderen5026]

This guy is a straight up genius. I've never heard someone put so much detail and care into a block build. Kudos

[@adiceak7330]

My Sti engine blew up and I am happy because Mike has that mischievous smile

[@anochieugochuku7176]

He must be the easiest person to deliver bad news to. He always looks like he's about to crack up after hearing the funniest joke.

[@andyMutale]

That's a double edged sword though, I mean you really don't know where you stand till the moment you see him give you a hand,...your hand... , with that delightful smile of his(damn he's got a great smile). He could tell you go to hell and you would look forward to the journey... damnit it's too late for me...save yourselves you fools I will now be doomed to watching and liking every video on this channel......*** Voice is drowned off by KZbin advert without next botton*** (seriously I'm enjoying this)

[@showalk]

@@andyMutale - You okay, bro?

[@Nazareth69420]

@@andyMutale drugs forsure

[@davidf7rt]

I loved every second of this almost 46min video, even not being a Subaru guy

[@THESLlCK]

not a subaru guy at all but would watch twice

[@elchivasregal5950]

Yes the same i don't own a suburu and I enjoyed the video

[@detectivebloor4011]

Im a subaru guy and as such am honor bound to encourage you to become a subaru guy.

[@canton7180]

this is not subaru stuff" specfically this is performance car stuff which transcends makes and model, all the principles he talks about apply to any engine, mean loading, engine speed, ve, etc 90% of what he mentions are things that applied to my non subaru engine build.

[@davidf7rt]

@@canton7180 totally agree

[@Kawaii_Life.]

Mike is basically a walking automotive-related encyclopedia. Another great advice to add is having a great tune and always addressing any issues that the car has, immediately!!

[@ShogunAutoworks]

Improve the pcv setup and do everything you absolutely can to prevent oil blowby getting oil in the cylinders and causing detonation. With such a short small crankcase the pcv for the case is right by the crank which is spinning oil all over and oil vapor and it sucks the oil mist right up and either cakes up in the pcv or sucks into the intake and into the cylinders ruining the cats as well as causing damage under boost, caking up on valves etc. Boosted, even worse blowby forcing it right up the pcv

[@hpa101]

Great watch, nice work team - Taz.

[@LOL-dk6xi]

I want him to build my engine just because he is always smiling lol

[@LFshlevin]

you can tell he loves cars, mike is the man

[@DarkDisc1]

Powered by happiness

[@crnkin2]

I want him to 1: build my engine; and 2: give me cuddles

[@monjier]

Idk about you, but this guy looks like he's moments away from laughing hysterically 😂

[@chriss1914]

That is the power of weed my friends.

[@fizzle5294]

Almost lost it when he pulled out that finger on stick. Was already close with his contagious smile.

[@kartman707]

Reminded me of old best motoring videos, they used the same thing to point out stuff on the engine bay 🤣

[@MistaIntake]

He smiled the whole time cause he knew it was gonna blow up either way.

[@0xadada]

this comment killed me. i'm literally dead.

[@dreamzzk7794]

@@0xadada come back

[@MichaelCoolGuy86]

As someone who studied automotive engineering, and who has taken material science classes along the way, I absolutely love the technical detail he mentions in this video.

[@Yo-mv6py]

what kind of careers can you get out of that? im super interested in this stuff i was thinking about studying while watching this lol

[@JAM4382]

I hope this is a series. I’d love to see it being assembled and then tuned etc..

[@motoiq]

This is part of our GD WRX project, so be sure to subscribe and keep an eye on the project: motoiq.com/category/projects/subaru/gd-wrx/

[@johnd5805]

@@motoiq yes great just subbed

[@Force1Com]

@@motoiq yeah I wanna know what all those parts do on the dyno and in the car, and how much it costed, lol

[@boppernostopper8598]

@@motoiq its a great build but those eagle rods should be last resort!

[@boppernostopper8598]

@Feral Man lol

[@DownToTheFrame]

This is the type of content KZbin needs! The amount of performance improving techniques that are shown AND explained is pure gold! Well done!

[@sandman900rr]

Well said!!

[@quacko11]

ive never see someone so passionate about his job #wholesome

[@ghostnic8]

Mike, I've spent years building engines and it took that long to dig around and build up the core knowledge you outline in this video. This is without a doubt the most comprehensive and concise run down of building and modification details I've ever seen. Obviously there is some esoteric detail that is Subaru specific but from beehive springs to rod ratio to hone plates to valve shape and porting. This stuff applies to really any performance engine build. Thanks so much for this, man. I'd encourage anyone interested in engine building to go through this outline and dig deeper into each section Mike has covered here. There are ways to do some of what he's outlining in this engine build that are not as expensive. CNC porting is the best but even a little care and skill with a die grinder will yield good results. Blending the valve seats, getting the block prepped well, deburring, matching the water jacket ports with the head, finding the best parts you can afford and parts that work well together. What the running characteristics are that don't translate to dyno numbers but do offer a better, smoother performance. Good stuff.

[@byloyuripka9624]

wat r u on m8 u shood not diy the head without a flow bench

[@rocketsmall4547]

so much work. im just gonna drop in a used boxer engine and call it

[@aAverageGuy]

I love how indepth you go into the how and why of the build, instead of just slappin on parts. Makes me wish I learned more during FSAE before i graduated

[@weedshoes5089]

As some who created an FSAE team, you don't need FSAE to build and learn.

[@liamsparling]

I’m addicted to this guy. He’s so smart and genuine. Reminds me of my grandpa and his car shop. Super awesome I’m glad I have the opportunity to watch and learn from these videos

[@the_JDM_fanatic]

This dude is such a smart dude to listen to , I love it

[@robk5745]

The information on getting the block ready for power is priceless. The flexy block is no doubt a big factor in blow ups

[@ajgagen1446]

It’s amazing how much this guy loves what he does!

[@KillerBMotorsport]

Great Video! Glad we could be a part of it, and looking forward to future updates and builds!

[@Berserkaru]

Couple more KillaB vids would be rad

[@ericramos3416]

My Subaru is my favorite car ever. I ran her to 250000 miles + before she just gave up. All stock. Commuter and traveling miles. 18 years.

[@hollowsun2407]

My Impreza is at 357k. Every extra day I get with it is a miracle and a blessing.

[@Aaronkatriel]

He knows so much it’s wild. Look at the constant smile.

[@gottabtru1]

He is so chill and knowledgeable.

[@AntiATF]

I love how Mike can't talk without smiling. Literally any video of Mike makes me happy lol

[@fehlrock]

Ya got to love a man that smiles continuously during a discussion of his work. Genus

[@El_Chompo]

What a masterclass on engine building. I would love to see this much knowledge and detail go into the full build of an entire track car too.

[@NorthernRiderOffroad]

I feel like he is the most likeable guy on the planet. Lol

[@violinmiata]

I remember Mike Kojima from the Sport Compact Car days. Always a passionate fountain of information! Cheerful explanation of knowledge way beyond what mortals can comprehend. He’s a national hero! If he builds something, it’s the bees knees

[@briansmobile1]

Nice pointer Mike. Good for increased smiles per gallon. lol Fantastic engineering detail to critical areas and surfaces.

[@BlackestBeard]

This is at least a 20k motor build with all those treatments, cnc’ing, precision parts and that’s without labor.... I’ve watched it twice now, and enjoyed it a ton.

[@aygwm]

All that into a stupid Subaru engine 😂

[@BlackestBeard]

@@aygwm Stupid expensive for sure.

[@Tzalmavet]

As many Subaru guys will tell you, if you're going to build an EJ for high power you do it right the first time.

[@4pimp4]

His knowledge and understanding is amazing. Truly the perfect EJ engine. But also, Im pretty sure the engine by itself costs $30K+

[@FADWC]

I keep waiting for him to laugh at his own joke lmao his smile is so contagious hahah

[@andialessio8238]

imagine having an internship in this garage🤯what a guy he is basically a walking encyclopedia...what a great video with detailed description and explanation...you are awesome👌

[@shalopez420]

I've never head anyone who sounds so stoned manage to successfully explain a complex topic so well. Great explainations and information. Thank you for sharing. PS I'd love to see a EZ30R build.

[@CDTJosh]

I was waiting for this guy to start laughing the entire video. He's so happy about what he does. His knowledge is next level. Youd sleep easy thrashing an engine built by this man.

[@ReignofStorms]

"It's not really just a subaru motor thing, it's a flat motor thing" Subaru owners: I liked that :)

[@mo_yakbass_9138]

Just love how he has a smirk the whole time, Mike loves his job!

[@scottt4081]

Wow! He knows every aspect of engine building without a pause or second guessing. Very impressive!

[@valiosubaru]

Would be nice to release a second part with the assembly process.

[@mattswank]

And seeing it actually running and working how they hoped. Not that I doubt it, I just would love to hear this thing and see what it finally put out power-wise.

[@iwanta69rs]

most underrated car channel on youtube.....23k subs? what?!

[@djrixxard]

This is a hall-of-fame youtube video for motorsports fans. The level of detail and education here is unmatched, and Mike's smile is magnetic!

[@enduroman80]

It's amazing to see someone with so much passion for his work. He was smiling throughout the entire video.

[@H3ntairican]

I love these technical videos so much it really makes you look at engines differently and appreciate the engineering behind the scene

[@jaredfox777]

Mike you're very informative and it was very well explained. I learn something new everytime I watch this channel. Great content keep it up!

[@turbochargersutututu]

I'm supposed to be writing a report for my Master's project that's due day after tomorrow, and here I am watching full videos on how to build my favourite engine ever. No regrets.

[@hidheaven6694]

I could listen to him speak for days!! So much knowledge!

[@Dis-Emboweled]

I agree the KillerB oil pan, baffle topper and pickup are a worthwhile investment for the Ejs. I actually never knew there was a option besides the harmonic balancer. That's pretty cool! Great video. I'm hoping you guys do follow up videos on the building and final numbers.

[@sandman900rr]

I want to see the parts coating invoice stack from this one project..

[@icemantuck2638]

Ditto. Very curious to hear more about where it was done and what the $$$ was.

[@b.r8204]

They did say they will build them for us

[@peted5217]

The costs are covered in followup vid. Ya the coating/surfacing services aren't inexpensive. Noted: the big thing on this motor is the use of 'torque plates' to duplicate assembled distortion during machining ops. For better power , longer engine survival.

[@ethansmith800]

@@peted5217 who use's this exact process when they machine the cylinders? IAG? Anyone you know of? I want to have my RA block honed and maybe bored a bit.

[@eduardvorobiev75]

It’s like listening enlightenment mantra…I’d go to this mechanic just to get peace of mind for real

[@yawny9710]

guy is a master of his craft and its delightful to watch his face light up while he explains everything.

[@justicejackson927]

Great video. He really knows what he's talking about and explains how all the parts he choose help improve reliability and power. Hopefully there's one about the 4G63 soon!

[@dannygomez4271]

And 4b11t 😁

[@GlobalMediaInc]

Great Breakdown, Mike... Full Of Tips & Very Detailed Information...

[@goobygoob9312]

This dude has a constant smile for 45 mins straight, I love it! 😂😊

[@starseed-]

This energy is amazing, a man truly happy about what he knows/experienced and is so willing to share to everyone willing to learn.

[@martokisful]

Thank you for such wide knowledge, it's always appreciated even if not building an EJ

[@NubeCubes]

I fully expected him to say "Don't modify it." and that would be the whole video.

[@DRIFTERDANS240]

Definitely one of the most detailed informational video I’ve watched on engine reinforcement and longevity. Well done

[@fishmanroly7450]

I don't even own a Subaru never have but I have been looking at the new WRX and the KZbin algorithm brought me to this video. Even though I don't have any plans of doing any mods I still found this video so entertaining and relaxing love how he smiles throughout the whole video.

[@motoiq]

Welcome aboard!

[@bengibson3955]

This is fantastic info. I’ve had an EJ257 that was a bit of a test bed when it was put together about 10 years ago and has been subjected to lots of circuit (road course) use as well as street use. I stuck with stock stroke but used long rods with custom short CP ceramic coated pistons. I’m also running Kelford cams/retainers/springs with high lift 264 cams. I’m using Possum Bourne Motorsport 14mm head studs/TGV deletes. Some things used here are a bit different (probably better here if I’m honest) but I’m cheering about the similarities between this one and my slightly oddball build back then. Excellent content and presentation!

[@mybrokengoldwing]

Looking forward to hearing and seeing this thing, once it’s built.

[@WheelmanMike]

Mike is the man!!! Absolutely love how he geeks out on everything.

[@robertortiz3345]

i like how mellow and chill he is explaining this... this guy is in no rush ever

[@JJBTEXAS494]

Would love to see this series continue. Always love built subaru 2 liters.

[@truthseeker7084]

I'm telling ya coming from a owner of a 02 wrx with a ej205 built with a stroker kit hands down love it. 92.5mm pistons and Manley rods h beam. Sti crank heat treat,td05 20g turbo,750cc inj,fmic ...etc,etc. 400whp daily driver 30k miles no problems.

[@nathansmith9812]

How many more miles you think you’ll get out of it?

[@truthseeker7084]

@@nathansmith9812 prob another 45k till I change the timing belt again it's all in how you drive and maintain plus I built it right. Doesn't even burn oil at all just saying.

[@ArbolRojo]

who is this guy? I'm only 3 minutes into the video and I already love it.!!!

[@Hannah-451]

Beautifully done and so gracefully explained. You know someone understands their topic when they can break it down and make anyone understand; especially while holding that smile and personality all the way through. I love how you enjoyed imparting this knowledge, thank you 💝

[@GCMoto97]

I love this video. It is very similar to my build right down to part selection and reasoning. The only difference is I didn't have all these metal treatment options near me at the time of my build, and some of the parts I picked aren't as aggressive (cam, crank). Nice! :)

[@dsxmotorsports]

Remember the good ole days when we ran extrude honed b series intake manifolds and they kicked all the asses? Well, these oil gallies need that love! Soo many rough and sharp edges, all working against the surface tension of the oil and adding heat and friction!

[@alexandresimard4230]

This guy know so much and put it in word the right way, as a mechanics who's now into engineering, I'm loving it!

[@head0927]

Dont even own a subaru and still watched every second. My addiction.

[@dyingbreed5386]

Those are great cams for a EJ25 Hybrid or EJ25 with AVCS removed as well. I used them on the latter with e85 and a TD series turbo. I hit 27psi at about 3.8k and it held almost to redline. Because it was easy to keep the car above 3.5k lag was non-existent. But I went with forged internals without any other shortblock strengthening so I ended up with a hole in the block large enough I could grab the crank with the engine still under the hood, haha.

[@denzelleon1655]

Had me at, “that doesn’t blow up” 🥵😂

[@TheChemicalBassist]

The level of knowledge, and the attention to detail, and the level of quality that goes into the parts for this engine are incredible.

[@iancooper5615]

What a brilliant video, more informative than the majority of the internet. I don’t even like the EJ but its compelling due to your knowledge 👍🏼👍🏼👍🏼

[@MobileAutoElectric]

As a LS guy. This is just insane to get 400 ponies reliably. this is Art

[@MobileAutoElectric]

Edit. all future builds will be WPC AND CRYOGENIC TREATED

[@christophergruenwald5054]

I’m making 463/506 to the wheels. Been there for over 20,000 hard miles so far.

[@woohunter1]

@@christophergruenwald5054 still holding up good?

[@graemedicks3139]

Inate Smile - Information well delivered with a smile!

[@PressurenFlames]

This is the type of video I love to watch - even if I'm not a Subaru guy. Very professional. Thank you for sharing your knowledge!

[@ziggyortiz37]

I’d love to pick this guys brain on building engines. This guy is brilliant and very knowledgeable

[@ashishpatel350]

Imma sub cuz I like this guy's vibe.

[@Ma77riK]

ive been waiting this ENTIRE video for this guy to burst into laughter, im stressing about it....

[@Spollekop]

Every video of this channel that I watch shows me how far ahead of the curve they are. All the little details add up to such a high quality job. That cnc valve job is a beautiful sight to see. There is so much knowledge here.

[@Far2hip]

That is the happiest engine tuner I’ve ever had the pleasure to watch. That was one VERY interesting lesson!! 👍🏻😎👍🏻

[@christiannieves4380]

Please keep the Subaru content coming!

[@MarcoGarcia-re3mk]

This guy's face probably hella sore after this vid . Smiles only

[@sazzayilmaz5055]

I find it so soothing to watch Mike smiling whilst talking about how to build a durable ej motor. Just sitting in my wrx in front of my workshop just watching this vid

[@leshreddur]

This Guy is the best, he knows everything about these engines... You can tell this is his passion, and he's happy as a clam to have this engine. I am a Diehard fan of Subaru's too man, Cheers Sir.

[@vehicularMCS]

Tell us about that sweet Pilot in the background...

[@sartajs6405]

hahaha, that thing is on nitrious;)

[@asahart2489]

When you want to seem like you know a lot about cars but that's the only thing you prolly know

[@cnknguyen]

I like the Best Motoring pointer stick technique

[@marvinbyrom1491]

Dear Mike, I have a Schwinn bicycle..if I just show it this video it will never be the same! Your work is brilliant. Thank you.

[@joshuacannar607]

That right there is passion on his face. So refreshing to see someone who is just happy to talk about and give in depth explanations about something he clearly enjoys. I think we've all gotten so used to negativity that seeing something like this is truly special

[@Haylem]

Can this guy frown? XD Smiles per mile!

[@spoolindsm127]

That’s why Japan has the EJ207 😂😭

[@TY279545]

This guy had a lot more theoretical and application knowledge than he is letting off. Awesome video, need more like this.

[@CVBFonzP7B]

i cant get over how this man literally smiled the entire video. i need that kinda energy