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Old 01-04-2007, 11:36 PM   #76
Ozzy
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How about a Porsche 997 turbo port.
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Old 01-05-2007, 05:47 PM   #77
Bob the fabricator
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Don't know if this interests anyone, but I recently flowed a bone-stock EG33 SVX head for a friend of mine. It was done on my Superflow 110 flowbench, measured at 10" of water.

Intake flow:
.100" - 49 cfm
.150" - 76 cfm
.200" - 101.5 cfm
.250" - 125.5 cfm
.300" - 146 cfm
.350" - 164 cfm
.400" - 166.5 cfm
.425" - 167.75 cfm
.450" - 167.75 cfm
.475" - 168 cfm

Exhaust flow:
.100" - 44 cfm
.150" - 62 cfm
.200" - 79 cfm
.250" - 92.5 cfm
.300" - 99.5 cfm
.350" - 104 cfm
.400" - 107 cfm
.425" - 109 cfm
.450" - 109 cfm
.475" - 110 cfm

You'll note the intake ports really seem to like valve lift, whereas the exhaust ports are not so good at higher lifts. Note the massive jump in intake airflow from .250" to .400" valve lift. Exhaust flow proportion is a bit low, so that seems to be where development might make the best gains in HP.

To convert my numbers to the common '28" of water' figure, multiply these numbers by 1.67. To convert my numbers to 25", multiply by 1.54.

Bob

Last edited by Bob the fabricator; 01-05-2007 at 10:09 PM. Reason: added more info
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Old 01-07-2007, 04:37 AM   #78
Marnix
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I've also measured MY94 EJ20G heads (hydraulic lifter) and MY03 EUDM EJ205 WRX heads. The WRX heads are the smallest I've come across so far, the actual ports are 26mm in diameter (round), whereas the EJ20G ports are D-shaped diameter 28mm and total width 30. Roughly calculated, the WRX ports have a total area of 1061 mm² (2 ports) whereas the EJ20G ports have a total area of 1511 mm².



That's probably why even well into Phase II territory, the WRC engine is still built using Phase I heads.

Last edited by Marnix; 01-07-2007 at 04:45 AM.
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Old 01-07-2007, 07:29 PM   #79
Hurley 2.5 WRS
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gee, wonder why the RCM Gobbstopper is using version 4 sti RA heads......

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Old 01-07-2007, 07:54 PM   #80
Patrick Olsen
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So, Ozzy, did you port those heads yourself? Both the intake and exhaust are opened all the way to match the gaskets? How much extra did it cost to get lights installed inside the heads for better pictures?

I just pulled my engine yesterday and should have some more pics of my Cobb-ported DOHC heads in the not-too-distant future. I did take one picture when I took off the intake manifold and the gasket was still in place:

I thought it was interesting that the ports are gasket matched on the injector side, but not the side closer to the block.

Pat
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Old 01-08-2007, 12:32 PM   #81
Matt Monson
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That's probably because the guys at Cobb know what they are doing. They know that there is such a thing as too big of a port and the impact it will have on port velocity. My ported SOHC Ej25 heads aren't anywhere near matched to the gasket...
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Old 01-08-2007, 07:24 PM   #82
Patrick Olsen
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Yeah, I'm with you on that one, Matt. With that said, I pulled the intake of the stock '98 2.5RS engine that I put in today, and the gaskets and ports looked the same. Hmmm... So apparently Cobb's porting and polishing is down farther into the intake ports. I didn't take any pics of the stock ports, but I have another set of stock DOHC heads in my basement, so I can do that later.

Pat
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Old 01-09-2007, 11:39 PM   #83
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I did open up all the way to the gaskets.
Intake manifold lines up almost perfectly with the unported ports, ie if you dont port your intake or make a custom one you will be going backwards. Im going to be porting my stock intake for now and eventually making a custom intake manifold.
check these out.
http://www.wallaceracing.com/runnertorquecalc.php

Last edited by Ozzy; 01-10-2007 at 01:21 AM.
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Old 01-10-2007, 01:19 AM   #84
Marnix
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There are primary, secondary and tertiary (sp?) wave lengths you can play with when designing intake manifolds. for practical reasons, only 2nd and 3rd wave lengths are interesting, as you would need extremely long runners to make the 1st wave length work.
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Old 02-06-2007, 11:26 AM   #85
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I really wish this thing was stickied so I don't have to dig everytime I want to add something!!!

Anyways, tore down an Ej20G from an auto tranny WRX last night. As best I can tell, the heads are IDENTICAL to manually tranny Ej20G's from '93-96. Castings are the same. Port measurements are the same, etc. etc. At this point, I have measured this on a v2 STi, a manual tranny '95 and an auto engine. No differences between any of them...
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Old 02-06-2007, 11:46 AM   #86
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isnt' the v.2 (gc8c) a shim under bucket? / a totally different design?
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Old 02-06-2007, 12:17 PM   #87
Matt Monson
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Quote:
Originally Posted by Jaxx View Post
isnt' the v.2 (gc8c) a shim under bucket? / a totally different design?
Nope, that's v3 and the EJ20K. The V2 was still an Ej20G and used the HLA's under the buckets...
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Old 02-06-2007, 04:12 PM   #88
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hmm that goes aginst some of the info i have. the v.2 is supose to be differnt it might be RA only though was this v.2 the one with the 5th injector?
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Old 02-06-2007, 04:13 PM   #89
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yes, only V2 sti RA was non hla
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Old 02-06-2007, 04:44 PM   #90
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Quote:
Originally Posted by Hurley 2.5 WRS View Post
yes, only V2 sti RA was non hla
That's correct. There's a lot of misinformation out there (including the Ken and Catherine sheets). Only the STi-RA had the following features: closed deck. forged pistons. solid lifters. I recently tore down an STI v2 longblock and it was open deck, non-forged pistons, and HLA's.
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Old 02-06-2007, 04:51 PM   #91
Hurley 2.5 WRS
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matt. i was under the impression that some ej20Ks are hla, whats thhat WRX motor you got have?
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Old 02-06-2007, 05:34 PM   #92
Matt Monson
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Quote:
Originally Posted by Hurley 2.5 WRS View Post
matt. i was under the impression that some ej20Ks are hla, whats thhat WRX motor you got have?
Not JDM ones. But that is where you hit a sticky situation since there were some '97 export market engines (like Austrlia) that were called Ej20K's but were essentially the earlier Ej20G longblocks with an under manifold inlet and wasted spark igntion. My Ej20K is shim over bucket, and from a JDM 5MT WRX. It came with the vin plate, correct ECU and VF22. And I have had the covers off. If someone is shopping and isn't sure of the origin, they could get one of those engines. But they should all have td04's on them if I am not mistaken...
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Old 02-06-2007, 06:50 PM   #93
Hurley 2.5 WRS
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ill have to tak a look when judd goes down if he hasnt already
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Old 02-07-2007, 08:43 AM   #94
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I will soon be able to measure a set of brand new JDM Legacy B4 heads (EJ20X/Y) and a set of very old JDM Legacy Turbo (EJ20'T') heads.

I've also measured the heads on the EJ204 (MY01?) engine that now lurks in the engine bay of my MY93 Legacy Wagon, will post those sizes later this week.
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Old 02-10-2007, 07:55 PM   #95
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97 wrx gc8d48d
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Old 02-11-2007, 11:35 AM   #96
Hovmerlin
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Does anyone have pictures of the Phase 1, dual cam, 2.5L engine, want to show heads etc.
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Old 02-11-2007, 02:38 PM   #97
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Quote:
Originally Posted by Hovmerlin View Post
Does anyone have pictures of the Phase 1, dual cam, 2.5L engine, want to show heads etc.
post 58
http://forums.nasioc.com/forums/show...7&postcount=58
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Old 02-11-2007, 03:22 PM   #98
FuJi K
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Quote:
Originally Posted by Hovmerlin View Post
Does anyone have pictures of the Phase 1, dual cam, 2.5L engine, want to show heads etc.
post #58 is of the '96 DOHC phase1 2.5L. the '97+ have slightly smaller ports from across the injector boss. Loses 4mm. They're in the FIRST post and a few other post where compared to the V7 STi BIG PORT
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Old 03-23-2007, 01:51 AM   #99
FuJi K
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where can this be stickied???
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Old 07-23-2007, 12:19 PM   #100
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I'm porting my USDM WRX heads here and I'll be replicating the JDM BIG ports. I'm using my '98 DOHC NA 2.5 head as my guide for what it should look like. There are A LOT you can take off from the WRX heads. You can make it look JUST LIKE the big ports, just takes "seat time."

I'll have pics up shortly.
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