We uncover some No No's when building your EJ25 heads!

[@mrphiscal]

The cam's kick the bucket!!!! 😂😂

[@coreyp_sti]

Dave built my N25 heads on my 800+whp STi. He recommended the S2 cam with conical springs and it lights up my 6466 full boost 40+psi at 4500rpm and carries it out to 8200rpm. 10K miles and countless pulls. Headgames knows their shit.

[@headgames]

Thanks Corey!

[@fredastaire6156]

Man!! This channel is the bee’s knees!! There is NO OTHER channel right now that goes into such depth and is as technical as this channel. I really hope this channel grows exponentially. I recently came into an EJ22T, I’m having it cleaned and building it myself. Currently looking for a set of heads to go with it and this channel is a god send!! Thank you!! ❤❤❤

[@headgames]

@@fredastaire6156 thank you so much!

[@pab3783]

Love the insightful Subaru content. I’m having an IAG 950 installed in my car. It comes w oversized valves. I’ll have to make the best of it.

[@jerodrobinson4040]

These are by far the best Head Videos on KZbin that I've seen by far. You actually touch on Velocity and explain that there's more to it than just making bigger Holes ..

[@headgames]

Thanks Jerod!

[@simbanugz2906]

Great video ! I always feel like I learn something. My brother- in- law had issues with his ej build. He eventually gave up took it to a local performance shop. He was told Cam to big kind of like how you guys mentioned. Man when he had the smaller Cam put in and right valve springs the car went from being lazy anytime under 4500 rpm to screaming at 3500 rpm. I'm going to make him watch this video. Funny as the mechanic told him " dont just order parts and mix match a build or you car will be slower Bigger is not always better on a cam"

[@GetaDomTune]

I tell customers this all the time

[@headgames]

the bigger is better mentaility is rampant. We just don't sell it. We lose some customers but we get the right ones.

[@JohnB-2021]

Excellent work, always learning new things from you.

[@headgames]

awesome! Glad you are getting something out of this! Thanks for watching!

[@johnsm007]

keep raising that bar you guys rock!

[@danielllewellyn5720]

Appreciate your thoughts and details about the oversize valves.

[@johnsm007]

Dave could you educate me and maybe others on "Spring pressure" and over 1:1 backpressure. How does high backpressure affects the spring capabilities.

[@headgames]

That’s a loaded question. I think that’s a great idea for a vid though! Thanks for sharing!

[@JaapGrootveld]

Nice...

[@Kyrazlan]

That front knife edge in the intake definitely needs deburred but it's not a hotspot. It's in the intake with massive amounts of air going past it. That wont even get up to the temperature of the coolant.

[@headgames]

you haven't seen one crack then. Air won't crack a head.

[@ThatGuy-yj3lu]

Do you guys torque the heads during the valve lash process? Ive heard a few head builders say that EJ heads will distort to a degree after installation, and some who recommend re-checking valve lash after the heads are installed to final torque. Trying to understand the best way to get the best clearances with something like the Kelford 35mm DLC buckets, which an end user cant just easily swap to the correctly sized bucket, in the event there is a lash change after final installation.

[@headgames]

we can't torque them to anything because there is so many different combinations of sleeves and stud sizes. Usually they don't move around enough to become an issue.

[@uwisho]

What’s your thoughts on GSC 5074 (dual conical). They look good but noticed you recommend the 5073 instead for higher HP. Dual AVCS sti running BC280s

[@headgames]

@@uwisho I don’t know, never used it.

[@uwisho]

@@headgames Cheers. Appreciate the content btw.

[@headgames]

@@uwisho thanks for watching!

[@kylealexander7893]

Couple questions about ej20 combuation chambers.. I'm currently planning a hybrid build with my 07 ej25 bottom end and ej20 heads with JE hybrid pistons..I'm not chamber matching the heads because of the hybrid pistons but I've read that people still mod the chambers by reducing the hard edge of the overhang that the heads have when matched up to the ej25 block. Would that be an improvement or just hurt the engine's performance? Also, wouldn't that effect my CR? Lastly, If I have the hybrid pistons can I literally just slap the heads on and call it a day with no modification to the chambers at all?

[@headgames]

I cannot fathom how a piston is going to actually fix the problem that the chamber is overhanging into the bore A LOT. I would never go that route or recommend it to be honest. So, as much as I love you and want to help I have nothing nice to say.

[@MrZapperdoodle]

Are there any differences in your process between the S20 and W/D/B/V style AVCS heads?

[@headgames]

Depends on the whp. We don’t do full ports to the s,d and v.

[@derricksteffen3722]

What do you mean you cant get beehives to work? You mentioned GSC5073 but ultimately went with GSC5076, but also went from s3>s2 camshafts. Does that mean you'd recommend 5076 with s2's and 5073 with s3's? I'm curious because my car is using s2 camshafts w/ beehives @700hp and I'm near the recommended boost limit of the beehives.

[@headgames]

I might have messed up the part number for that! Good catch. I didn’t watch it but we would do the 5073. The beehive won’t be happy at 700whp or more. At 600ish we have float issues.

[@saki10man]

@headgames so would s1 with 5076 spring kit be overkill. B25 heads eventually going for 600? What spring kit do you recommend for s1? 5073 or 5076

[@headgames]

@@saki10man 5076 is perfect

[@TyMilner177]

Any experience with the polyquad idea?

[@Hebert6760]

For ej257 dual avcs, What valve springs brand/material/pressure do you recommend for a 500hp with stock cams/heads?

[@headgames]

@@Hebert6760 GSC5076 would be your guy.

[@Hebert6760]

​@headgames in what situation do you use a higher seat pressure and open pressure? I this video you mention 80 seat pressure and was wearing the seat out or that was just because the material?

[@headgames]

@@Hebert6760 around 650 we jump into much more pressure. Then we would get into the GSC 5073 conical with 100lbs on the seat

[@moisesr7840]

I wanna build my heads for a 600whp subaru on 28-30 pounds of boost. What head set up would you recommend?

[@headgames]

@@moisesr7840 check out our Power Pak 2. Has all the parts you need and service. You would want the pocket port, all the GSC valvetrain, s1 cams and add on service EJ-GC. If it’s not going to see 600whp all the time I would suggest sticking with the stock cams. They are very good in the 550whp range.

[@headgames]

@@moisesr7840 cdn.shopify.com/s/files/1/0725/1676/3953/files/001-Subaru_EJ-Powerpak2.pdf?v=1697043901

[@GroovesAndLands]

Dave, my understanding is titanium is prone to cracking anywhere there is a sharp edge or scratch. Is this a concern of yours? Do you think the peening/wear of the spring into the retainer is a problem in this regard? Obviously titanium is lighter than steel - but steel is tougher, harder, stronger and cheaper...at what point do you think its necessary or "worth it" to bother with titanium? Thanks for another interesting video.

[@headgames]

honestly, we have never seen issues with ti retainers unless there is an unhappy spring. The only time we suggest steel over Ti is if the budget is tight and there is a steel option which is seldom. Great question and thanks for watching!

[@CJ5EVOLUTION]

I have heard you saying in different ocations that you don't see the Beehive spring working accurately at least as what I understand at high RPM levels and moderate boost levels, but at what range of RPM and boost you see them suitable for doing their intended design work.

[@headgames]

Under 600whp is perfect

[@dimenshion]

Man those look very familiar. Did they come from WA from a certain 2011 hatch built in Kent WA?

[@headgames]

No clue to be honest

[@brianknight4595]

David did you earlier say you do not use a gasket to mark out & scribe to have lines to work to ? Which what I do cheers BRIAN

[@headgames]

I don’t go outside go outside the factory lines.

[@rebel.mma.youtube]

I want to stay within standard power so crank 360-400max power. What things i can do to the heads? I been reading about 4 years waiting for my engine to get old enough to rebuild. I'm here now and still confused. I think need oem valves but it the springs and cams im still stuck on? Which video can i go to

[@headgames]

What engine are we talking about?

[@rebel.mma.youtube]

@headgames oh so sorry. A subaru 2.0. Ej205 I have with non avcs.I have a wrx 2001 so just want to get a short block rebuild heads and stay at standard limit for bottom end which I understand s around 360-400bhp at crank. I have two options. Thick walled block and an ej207 but the thick wall is cheaper? Is it not as good? I want longevity. My current engine us 130k miles and still going strong. So would love another 130k miles over high power and a rebuild at 50k miles.

[@headgames]

@@rebel.mma.youtube for 400whp I would stick to stock valves, do a rebuild and do a gsc single spring. Just so you have some extra cushion for the pushing.. stock cams are great up to 550whp

[@rebel.mma.youtube]

@@headgames really appreciate it :) Shame in the UK.

[@rebel.mma.youtube]

@@headgames is porting the heads necessary?