Project Billet - Ported VS. Stock Subaru EJ Heads - Benefits and Comparison 

I love how the camera guy suddenly realized the pinup calendar was in the shot and panned over.

Keep up the good work. Thank you for all the helpful videos you done!! always good to learn new stuff, Especially in the middle of a build.

Love the info! Thank you for making these videos!

i wish i would have ported my heads when i built my motor, it is now my limiting factor. good video

When trying to match cams with a turbo, my first reflex would be to take cams with an hurley exaust valve opening and a longer overlap time with the inlet valve (high rev cam design) to compensate for the spool up restriction. If there's some air/fuel mix lost in the manifold between the exaust and combustion stroke and pressure remaining from the combustion then it will help to spool up the turbo faster.

Nice! this was great info to know!

Thank you you did a video!! I need to see part 3! I mean, I need to see everything about EJ25, so I can have the knowledge to know what I need and want to be done on my '09 STi Hatch! I need it AS RELIABLE (with proper driving of course) AS IT CAN GET. Actually on 400HP, but later, I will want to move to around 600HP, but only if it handles top reliability.

this is a top tier build, could have gone to dimpled design flow chamber, that would have the same exclusiveness as the block has.

great series

good work and good video ..

I was waiting for this head falling since 0:24

The two dislikes on this video are from the cams in the head that tipped over XD

So do you guys build the heads yourself? And port out and polish the factory head? Or do you buy a whole separate already ported complete cylinder head from a distributor? I would like to know where to get a complete assembled built cylinder head like that.

@MRTPerformance do you guys do any work on mitsubishis? Id love to hear what you have to say and any cool info you can give me on the 4b11t engine from your experience! The things you share are unique compared to what a lot of people make videos on. You give a different perspective on engines and reliability through your exerience, i love it.

Any benefit of building a 2.0 bugeye motor? Or should you just build a hybrid? I heard you can take a 2.5 sti block and stock 2.0 heads and it would work. Not looking to run stupid amount of power. 300-320 maybe

@mrt performance is it worth running a ported head on a stock shortblock?

What is the logical order of head modifications on EJ25 , in my case SOHC heads with delta 1500 cams.. 3/5 angle valve job... port and polishing, bigger valves, etc. Planning around 23psi @ 6850-7200rpm (Centrifugal SC).

2:44 that cylinder head fell , but nice talk on the heads on Subaru

In my experience porting and big valves along with supporting mods gives you the same increase as it does on normally aspirated. To give an example of what it can do, there's a guy running a VQ37 naturally aspirated that puts down 557hp at 8000rpm. That will smoke a stock GTR. So done right it can do an insane amount. That VQ37 would make around 1000hp on 20 psi of boost on E85. How much boost do you need for a stock head and cam GTR? You would need 35-38 psi boost to hit it, 1 bar more than the race ported and cammed engine. Obviously both would need built bottom ends. But the idea is clear. Porting and Cams is the first thing if I open a motor 😍

wasn't this engine in a liberty project car?

awesome vid. how much airflow was gained (at what lift/pressure) from porting? was there more work like a valve job to complement the larger valve size or was it deemed unnecessary?

have you found any benefits to milling away some of the combustion chamber to reduce valve shrouding but making a more rounded chamber?

Is mtr performance still going????

so the cams and valves are key. the rockers and Springs wouldn't need to be upgraded on the head to work with the new valves and cams?

hmmmmm, you know the prodrive v1 ej20g heads were cast in house by prodrive - that the ports are actually SMALLER but produce more torque and power, there is a supplier in UK (i think) that sells billet heads that incorporate the prodrive design to a billet head with some mods, according the the website they go pretty good haha

So if you are modifying a subaru, upgrade the entire pistons to forged

Hey, Brent would you recommend buying a high mileage STI?

Isn’t it true that having a slightly rougher port rather than a polished port actually flows better because, the rougher port causes the air to have a turbulent effect on the air flow and causes the air to swirl and actually flow better than a highly polished ported surface...????

Is there anything Brett doesn't know about the Subaru

good old fashion engine building.

Can you stroke a 2.5 engine?

Now you just need to anodise the heads gold as well (Y)

should go water to air inter cooling on this build

Don’t run stupid boost! Haha, good one.

Hog it TF out!