Tehnation Posted June 4, 2014 Share Posted June 4, 2014 So I'm planning my engine build, forged pistons and rods, not sure about specifics yet and sti nitrated crank, simple enough. But then I started researching cylinder heads and came up short. My main concern is I want heads that can handle 7500-8k rpms reliably(will last 50k+ miles of abuse before next rebuild). Can I swap to sti heads or other ej heads easily or do I need to rebuild with better cams? If cams any recommendations. I'm looking to make around 500hp+. Link to comment Share on other sites More sharing options...
Max Capacity Posted June 5, 2014 Share Posted June 5, 2014 In the powertrain forum or this one check out the couple of threads about the higher HP builds. Some head info there. If I were you, I contact Mike at AZPinstalls.com he's close to you and most likely can answer all your questions in one email. Oh yea buy your cams and valve kit from him. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
GEE-OTTO Posted June 5, 2014 Share Posted June 5, 2014 Just go with roller TBs one for each head...one can dream at least Link to comment Share on other sites More sharing options...
MrTris Posted June 6, 2014 Share Posted June 6, 2014 The stock heads, rebuilt, can handle that RPM level. I doubt you'd be maxing out your cams, but you could get a custom grind from Delta, if you wish -- It's reasonably cheap. (~$200) PnP, flow test, and rebuild your heads with a Brian Crower setup and you should be OK 'til about 8. Why do you want to be that far out, though? What's the point? Without going TT, you're not gonna have a solid HP or TQ from 3-6, and after six and a half, most everything's gonna drop off. Yes, you can do STi heads, and I know a guy who has a set of W25s, freshly rebuilt, that he'd like to unload. To make use of the dual AVCS, though, you'll need the STi electronics, which I think means you'd basically end up doing an STi swap. Link to comment Share on other sites More sharing options...
Tehnation Posted June 6, 2014 Author Share Posted June 6, 2014 Seems I have a lot more googling to do. Why more rpms, cause racecar! Higher rpms are always better! Link to comment Share on other sites More sharing options...
Tehnation Posted June 6, 2014 Author Share Posted June 6, 2014 Not sure how to explain it but heres an article that would give you an idea. http://rehermorrison.com/tech-talk-47-raising-the-redline-why-rpm-matters/ Link to comment Share on other sites More sharing options...
Max Capacity Posted June 6, 2014 Share Posted June 6, 2014 Over in NASIOC there is a good thread about head porting and such. Before I had my buddies machine port my heads, I sent them the link. He told me that's what they have been doing to these heads for years. You can't just go in there and open things up. I think the thread was from Maxwell Performance. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
Moderators BarManBean Posted June 6, 2014 Moderators Share Posted June 6, 2014 To be clear, are you looking for 500bhp or 500 awhp? Pretty huge difference. For 500bhp I think stock heads would be fine...500awhp, maybe not so much. I believe that STi B25 heads (04-06?) are essentially the same and wouldn't be an upgrade for you. "Bullet-proof" your OEM TMIC! <<Buy your kit here>> Not currently in stock Link to comment Share on other sites More sharing options...
Tehnation Posted June 6, 2014 Author Share Posted June 6, 2014 http://forums.nasioc.com/forums/showthread.php?t=1941158 http://forums.nasioc.com/forums/showthread.php?t=2103960 Awesome, I love it! Link to comment Share on other sites More sharing options...
Tehnation Posted June 6, 2014 Author Share Posted June 6, 2014 500awp Link to comment Share on other sites More sharing options...
05sleeper Posted June 8, 2014 Share Posted June 8, 2014 Yea my 05 lgt has the b25 Sti heads but I went with the d25 heads on my new set up for a nice bump in compression. Also it's a more spherical chamber and redesigned coolant passages for more coolant flow. I did big PnP, valves, dual valve springs, titanium retainers, bronze manganese valve guides, gsc valve stem seals, 5 angle valve job and gsc s2 cams. Here's a link comparing b25, d25 and other heads. Post #5 at the end shows you the best differences between the b25 and d25. http://forums.nasioc.com/forums/showthread.php?t=1856856 Link to comment Share on other sites More sharing options...
boxkita Posted June 8, 2014 Share Posted June 8, 2014 Cosworth sells 8k rpm heads. If you want more they can get you upto 10k. Build my car Boxkita Track days Link to comment Share on other sites More sharing options...
Tehnation Posted June 8, 2014 Author Share Posted June 8, 2014 Cosworth sells 8k rpm heads. If you want more they can get you upto 10k. http://www.cosworth.com/products/performance-parts/cylinder-heads/ Are these the heads? Link to comment Share on other sites More sharing options...
Tehnation Posted June 8, 2014 Author Share Posted June 8, 2014 Yea my 05 lgt has the b25 Sti heads but I went with the d25 heads on my new set up for a nice bump in compression. Also it's a more spherical chamber and redesigned coolant passages for more coolant flow. I did big PnP, valves, dual valve springs, titanium retainers, bronze manganese valve guides, gsc valve stem seals, 5 angle valve job and gsc s2 cams. Here's a link comparing b25, d25 and other heads. Post #5 at the end shows you the best differences between the b25 and d25. http://forums.nasioc.com/forums/showthread.php?t=1856856 How much did it cost you to rebuild your heads? I'm going to weigh my options, the Cosworths are f'n awesome... real simple solution ready to go, $5500. I'm going to see if I can rebuild my heads to something of similar spec for 3k-4k. "Key Features: All new OE Castings Enlarged intake and exhaust ports Large diameter stainless steel intake valves Large diameter inconel exhaust valves Hi-rev, dual valve springs Titanium retainers Hardened steel spring platforms Reshaped combustion chamber on most applications Flow bench proven design Dynamometer tested Machined Cosworth logo Precision multi-angle valve job Pre-assembled, ready to install Machined port bore finish Knife edge port divider" Link to comment Share on other sites More sharing options...
Tehnation Posted June 8, 2014 Author Share Posted June 8, 2014 So I will need: springs, valves, retainers, seals, guides, cams, and pnp, am I missing anything? Seems like Ferrea is the way to go, other options are Supertech and GSC.... more homework. Ferrea Springs - $365 Ferrea Retainers - $265 Ferrea Spring Seat Locator - $115 Ferrea Seals - $40 Ferrea Guides - $130 Ferrea Valves - $615 $1530 GSC S2 Cams - $850 $2380 Hmmm..... guess i'll be doing more research on Supertech and GSC! Link to comment Share on other sites More sharing options...
MrTris Posted June 8, 2014 Share Posted June 8, 2014 GSC and Supertech have a great reputation in the Subaru world and are used by alot of builders who want uprated quality with a decent price. I would also look into Brian Crower - Link to comment Share on other sites More sharing options...
Tehnation Posted June 8, 2014 Author Share Posted June 8, 2014 Probably will need new buckets, maybe not. ST=Supertech ST Dual Spring & Titanium Retainer Kit - $340 ST Black Nitrated Intake & Iconel Exhaust Valves - $325 ST Seals - $10 ST Guides - $90 ST Cam Followers/buckets - $360 $1125 w/o buckets - $765 GSC S2 Cams - $850 $1975 w/o buckets - $1615 Link to comment Share on other sites More sharing options...
Tehnation Posted June 8, 2014 Author Share Posted June 8, 2014 GSC is pretty much same price, so I guess the new question is the beehive better than the dual spring? GSC Beehive Spring & Titanium Retainer Set - $370 GSC Intake & Super Alloy Exhaust Valves - $307 GSC Seals - $13 GSC Guides - $80 ST Cam Followers/buckets - $360 $1130 w/o buckets - $770 GSC S2 Cams - $850 $1980 w/o buckets - $1620 Link to comment Share on other sites More sharing options...
MrTris Posted June 8, 2014 Share Posted June 8, 2014 Headwork/Rebuild: ~$400 (most machine shops) PnP: Another ~$600 (?) Springs and Retainers $250 Valves~$250 Seals~$15 ____________ ~ $1500 Better upgraded options: Cosworth Springs ~$300 "Beehive" springs ~$375 Then there's the Crank you wanted, though, I think you can get it from Heuberger for about $275. (I think that's the one I saw on their Amazon listing this week.) You may also want a couple of these cam timing adjusters, too. I would also opt for these, if you think you wanna wrap out above 7500: Cosworth Head Gaskets All of these parts should be able to handle what you'd like to do, and with those timing adjusters and a good tune, you should be able to have better control of your powerband, especially since you'll be adding nearly 2000rpm to what you'd normally be able to run. Link to comment Share on other sites More sharing options...
Tehnation Posted June 8, 2014 Author Share Posted June 8, 2014 Cosworth.... damnit more homework.. also forgot about these guys http://www.headgamesmotorworks.com/ http://www.headgamesmotorworks.com/app/download/756312029/Subaru+EJ20-25.pdf They have some pretty good packages: subi port comp pack. (800-1200whp): port, install bronze guides, valve job, lash, mill, assemble with Ferrea dual spring-kit and comp plus stock size valves $2,899 subi port gsc pack. (600-800whp) port, install bronze guides, valve job, lash, mill, assemble with GSC beehive spring-kit, Ferrea 6000 series stock size valves and locks $2,299 subi pocket port pack. (400-600whp) install bronze guides, valve job, lash, pocket port, mill, assemble with GSC beehive spring-kit, Ferrea 6000 series stock size valves and locks $1,700 Link to comment Share on other sites More sharing options...
Tehnation Posted June 8, 2014 Author Share Posted June 8, 2014 Guess I'll go the single beehive valve spring route, either Cosworth or GSC because they are lighter, less mass, and less force on valve train, buuut I think I need more research. Anyone know if the GSC S2 Cams can be tuned with stock ecu? Link to comment Share on other sites More sharing options...
Tehnation Posted June 9, 2014 Author Share Posted June 9, 2014 Anyone know what crankshaft came in 05 lgt? 12200AA330 ? Trying to figure out why I would buy a new crankshaft if the one in my engine is already forged or good enough. But that's another day. Link to comment Share on other sites More sharing options...
MrTris Posted June 9, 2014 Share Posted June 9, 2014 Your stock crank can handle some insane number that you'll never actually be able to exceeed. I wouldn't sweat it. Stock ECU? On your setup? Ha! You need a Megasquirt. Link to comment Share on other sites More sharing options...
Tehnation Posted June 9, 2014 Author Share Posted June 9, 2014 I guess its time to gather a big pile of money and some matches...... Link to comment Share on other sites More sharing options...
Tehnation Posted June 9, 2014 Author Share Posted June 9, 2014 Hmmmm, I may be able to get away with stock ecu, I sent an email to GSC, going to see what they say. Aftermarket ems is where things get out of control, anti-lag, launch control..... oh god. The GSC S2 has power from 3500-8.5k... thats f'n amazing. Link to comment Share on other sites More sharing options...
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