Welcome to the North American Subaru Impreza Owners Club Monday July 28, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Built Motor Discussion

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 06-25-2008, 06:17 PM   #1
JackHammer
Scooby Newbie
 
Member#: 180815
Join Date: May 2008
Chapter/Region: Tri-State
Location: me birfday
Vehicle:
I want 2 be like
Gen "me" gimme $ please!?

Default Flow Data? .5mm vs 1mm oversized valves and/or porting?

Hey guys,

Just wondering if anyone has some head flow data on .5mm and 1mm over sized valves?

There's so many combinations of .5mm with stock ports, 1mm with stock ports, a combination of .5mm and 1mm valves, porting your heads (not too much ) aaahhhhhhhh, it will drive your brain insane.

I know there isn't a 'BEST' combination, but I was thinking for my build to do .5mm intake and 1mm exhaust with some very MILD touch up work to the intake and exhaust ports. i want to get the exhaust flowing. In all reality, .040 isn't much when considering "big valves" in heads!

I have heard that phil from Element tuning say that increased valve sizes really get the heads flowing.

Quote:
Originally Posted by MeetMrGlock View Post
- while we're at it, we're going to do oversized valves. based on phil's experience, he believes that porting is not as important as installing larger valves to get these heads flowing, so, to the flow bench we go.[list]


Currently im running a gt35r kit on the stock-ish motor. I would just like to increase the flow a little bit. The car is mostly a daily driver and will never be a 1/4 mile-r. More of a road racer.

Anyone have charts with flow data for your increased sized valves? Did you do port work also?

thanks!!

this is about the only flowchart i've seen

* Registered users of the site do not see these ads.
JackHammer is offline   Reply With Quote
Old 06-25-2008, 07:18 PM   #2
flycaster
Scooby Specialist
 
Member#: 60142
Join Date: Apr 2004
Location: Bend, OR
Vehicle:
2011 WRX
Grey

Default

That's a great chart...I'm curious as well.
flycaster is offline   Reply With Quote
Old 06-25-2008, 08:02 PM   #3
Homemade WRX
Scooby Guru
 
Member#: 33782
Join Date: Mar 2003
Chapter/Region: MAIC
Location: 3MI Racing LLC
Vehicle:
96 bastard child
search FIRST, then PM!!!

Default

I did have it all done but my hard drive and it took a crap and died on my old laptop. I'm sure I'll be doing the test again.
the results on an STi head were unquestionably +1mm from the testing. Of course a .5mm could have its benefits with a lower cfm (pressure mainly) flowing motor.

Last edited by Homemade WRX; 06-25-2008 at 10:03 PM.
Homemade WRX is offline   Reply With Quote
Old 06-25-2008, 09:30 PM   #4
tech@epr
Scooby Newbie
 
Member#: 183243
Join Date: Jun 2008
Chapter/Region: MWSOC
Location: DFW area (TX)
Vehicle:
92 Nissan 300ZX TT
black

Default

The majority of your flow traits are dependent on a few variables..one being valve angle to the seat. Doing a competition valve job is the most crucial i've found when I cut valve jobs on any cylinder head. The other is to set your throat which is where you transition the port to match the deminsions your setting. Third blending is the most precise and labor intesnsive part of the entire ordeal. If you have any questions regarding flow or cylinder work feel free to PM me.

have fun.
tech@epr is offline   Reply With Quote
Old 06-26-2008, 02:53 PM   #5
modaddict
Scooby Guru
 
Member#: 95840
Join Date: Sep 2005
Chapter/Region: NWIC
Location: Pasco, WA
Vehicle:
sold to a good bud
awaiting next car

Default

Quote:
Originally Posted by Homemade WRX View Post
I did have it all done but my hard drive and it took a crap and died on my old laptop. I'm sure I'll be doing the test again.
the results on an STi head were unquestionably +1mm from the testing. Of course a .5mm could have its benefits with a lower cfm (pressure mainly) flowing motor.
Very interesting thread.

Micah, when you say "lower cfm (pressure mainly)" are we talking less than 25psi? reason I ask is cause your "low" may be different than mine.

What do you mean it could have it's benefits on a .5mm? That potentially it could flow MORE at a lower psi?

Just trying to learn.......

BTW, I was hoping you would come out with your data........sucks that it's lost.
modaddict is offline   Reply With Quote
Old 06-26-2008, 03:00 PM   #6
JackHammer
Scooby Newbie
 
Member#: 180815
Join Date: May 2008
Chapter/Region: Tri-State
Location: me birfday
Vehicle:
I want 2 be like
Gen "me" gimme $ please!?

Default

Quote:
Originally Posted by Homemade WRX View Post
I did have it all done but my hard drive and it took a crap and died on my old laptop. I'm sure I'll be doing the test again.
the results on an STi head were unquestionably +1mm from the testing. Of course a .5mm could have its benefits with a lower cfm (pressure mainly) flowing motor.
1. So you think, even for a car that's a DD on a 35r, you would go with 1mm valves on both intake and exhaust?

2. Is there any machining problems when going with these to fit them in the head?

3. The main question: Where will +1mm valves shift the powerband?

4. right or left or the same?


Quote:
Originally Posted by tech@epr View Post
The majority of your flow traits are dependent on a few variables..one being valve angle to the seat. Doing a competition valve job is the most crucial i've found when I cut valve jobs on any cylinder head. The other is to set your throat which is where you transition the port to match the deminsions your setting. Third blending is the most precise and labor intesnsive part of the entire ordeal. If you have any questions regarding flow or cylinder work feel free to PM me.

have fun.
Have you seen a shift in the powerband?
I kinda like the stock ports for the velocity, but the exhaust seems to be less than desirable.

If you were to match valves to shift the powerband LEFT, what would one do as far as valve sizes choose? Can you shift it left with increased valve sizes......or even keep it the same?
JackHammer is offline   Reply With Quote
Old 06-26-2008, 03:41 PM   #7
Homemade WRX
Scooby Guru
 
Member#: 33782
Join Date: Mar 2003
Chapter/Region: MAIC
Location: 3MI Racing LLC
Vehicle:
96 bastard child
search FIRST, then PM!!!

Default

looking at the +1mm valve, I would expect there to be some shift but would be made up on the top end handsdown. Hence the stating a .5mm would be better for a street (who's concerned about loooow boost/NA power) or possibly those auto-xers
I've had no issues with fitting the +1mm and I will say to open up the throat too and at least blend it back to the port when doing this.
Homemade WRX is offline   Reply With Quote
Old 06-26-2008, 04:07 PM   #8
modaddict
Scooby Guru
 
Member#: 95840
Join Date: Sep 2005
Chapter/Region: NWIC
Location: Pasco, WA
Vehicle:
sold to a good bud
awaiting next car

Default

Quote:
Originally Posted by Homemade WRX View Post
looking at the +1mm valve, I would expect there to be some shift but would be made up on the top end handsdown. Hence the stating a .5mm would be better for a street (who's concerned about loooow boost/NA power) or possibly those auto-xers
I've had no issues with fitting the +1mm and I will say to open up the throat too and at least blend it back to the port when doing this.
Me personally, I can accept a small shift to the right considering I hit full boost a smidge over 4100 rpms.

I'll look into larger valves for my build I guess.

Coming from the old chevy days, I always increased the exhaust side to get it OUT! One would think that Like Jack said is that the subaru exhaust ports leave much to be desired. Maybe that's the way to go.

You would think if you could get MORE exhaust flow OUT everywhere and at ANY rpm, it would help "spool"/boost threshold......Would the 1mm exhaust's actually do that?
modaddict is offline   Reply With Quote
Old 06-27-2008, 06:54 PM   #9
charliew
Scooby Specialist
 
Member#: 125304
Join Date: Sep 2006
Location: Crawford, TX.
Default

I'm not reading that cosworth graph correctly I guess because it appears the ports max out at .350-.400 lift only improving 10 cfm from there on. Also it shows the stock sti to flow 60 cfm more than I am familiar with reading. My bench shows a stock sti head intake at .450 lift to flow 230- 240 cfm. I thought I read thats what other benches also flowed. With a 20 cfm improvement with mild porting. Cosworth shows a 50 cfm improvement with 1mm over valves so it looks like oversize valves give 30 about cfm more flow when combined with their porting.

I guess theres a 50 cfm difference in benches but it really doesn't matter, it's the improvement that matters.

The dog leg exhaust port shows a 70 cfm improvement with the .220 lift showing great gains.

Its a good improvement and shows that bigger valves really improve the flow. Course it doesn't specify valve size.

I would like to see a dyno of these heads on a 2.5 to see how much low end is lost with ports and valves this large.

Last edited by charliew; 06-30-2008 at 12:32 AM.
charliew is offline   Reply With Quote
Old 06-27-2008, 09:08 PM   #10
fwillyj
Scooby Newbie
 
Member#: 165640
Join Date: Dec 2007
Location: taylorsville Ut.
Default

-here is two new CNC'd heads from two different "C" companies---recently flowed on my SF300 flowbench at 25" test pressure.

-they both have +1mm oversize valves.
-the Cosworth heads have 1/16"/1.5mm larger exhaust opening at the header flanges.
-#4 exhaust on the Cosworth head is the dogleg----where the other C head the dogleg exhaust port is #1.

-the colored graph of the Cosworth flow does NOT mention what pressure they flow at---but it is obviously much higher than 25".
-----------------------------------------------------------------------
-looks to me like they flow the intake at 50"---where the correction factor is 1.414 for flownumbers measured at 25"---but then the exhaust looks like it might be tested at some other lower than 50" test pressure like maybe 40" where the correction to 25 " flow numbers is 1.265.

-Reason I say that is Cosworth says a stock dogleg port flows 210 and I see the stock doglegs flowing 167 at 25"----and that takes a square root correction of 1.265 to get from 167 up to 211.


valve----------COSWORTH CNC--------------------the other "C" CNC'd--
-lift--------int-2-exh-------int-4-exh-------------int-1-exh--------int-3-exh
.100”-----90.7- 87.8-----92.3--86.9----------96.5--91.6------95.5--93.9
.200”---169.4-191.3----169.8-180.2--------173.9-176.1----172.9-183.0
.300”---232.6-226.0----232.6-206.5--------234.5-210.6----230.7-221.2
.350”---252.7-228.9----254.6-208.0--------246.7-215.4----247.4-223.4
.400”---260.9-230.5----261.5-209.7--------256.5-218.3----254.5-227.3
totals-1006.3/964.5---1010.8/871.9-------1008.1/912.0---1001.0/948.7

-------------------------------------------------------------------------
-I copy and pasted this from the 2007sti thread

http://forums.nasioc.com/forums/show....php?t=1471829

so that you can see a little better honest comparison of how the CNC'd heads compare to fairly decent hand ported stuff.

-Also flowed on my SF300 flowbench at 25"
--------------------------------------------------------------------------------------
-2007 STI V25 B heads.

TEST 1-is stock, used & carboned up a little but fairly clean, used valves & seats.
TEST 2-ported pretty decent but to suit stock valve sizes---no valve job preparation yet.
TEST 3-seats are machined for 1mm larger valves and reblended the bowls to suit the larger valves.

(notice that oversize exhaust valves are a challenge to make'm flow as good as stock exhaust valve sizes

valve---------------test 1---------------------------------test 2--------------
--lift--------int-2-exh-------int-4-exh-----------int-2-exh-------int-4-exh
.100”-----87.2--73.4-----87.5---72.8--------87.4---70.2-----87.7--70.0
.200”---164.5-149.2----165.7-142.1-------164.5-154.7---163.7-158.0
.300”---219.1-174.8----220.6-161.1-------221.0-202.7---223.8-189.0
.350”---228.5-180.8----226.9-165.6-------237.0-221.8---235.7-203.3
.400”---234.8-184.5----230.7-167.8-------245.2-233.4---247.4-209.1
totals---934.1/762.7----931.4/709.4-------955.1/882.8---958.3/829.4

valve-------------test 3----------
--lift------int-2-exh------int-4-exh
.100”-----89.0--79.7------91.7--81.2
.200”---165.7-155.6----167.0-152.8
.300”---234.2-204.2----234.2-189.2
.350”---259.0-215.7----259.0-198.0
.400”---271.6-223.7----268.1-202.2
totals--1019.5/878.9--1020.0/823.4

Last edited by fwillyj; 06-23-2011 at 09:59 PM. Reason: more comparison data
fwillyj is offline   Reply With Quote
Old 06-29-2008, 08:37 AM   #11
modaddict
Scooby Guru
 
Member#: 95840
Join Date: Sep 2005
Chapter/Region: NWIC
Location: Pasco, WA
Vehicle:
sold to a good bud
awaiting next car

Default

FYI, there was some discussion on the boards a long while ago that cosworth flowbenched their heads at 50"
modaddict is offline   Reply With Quote
Old 07-01-2008, 11:56 AM   #12
JackHammer
Scooby Newbie
 
Member#: 180815
Join Date: May 2008
Chapter/Region: Tri-State
Location: me birfday
Vehicle:
I want 2 be like
Gen "me" gimme $ please!?

Default

Quote:
Originally Posted by Homemade WRX View Post
looking at the +1mm valve, I would expect there to be some shift but would be made up on the top end handsdown. Hence the stating a .5mm would be better for a street (who's concerned about loooow boost/NA power) or possibly those auto-xers
I've had no issues with fitting the +1mm and I will say to open up the throat too and at least blend it back to the port when doing this.
Would the correct way to do this be having the seats cut out and install new seats?

Essentially, aren't you just putting a bigger door on the seat when putting in a larger valve?

I'd love to see a stock set of heads with a not stock sets of heads.......right before my eyes.
JackHammer is offline   Reply With Quote
Old 07-01-2008, 02:48 PM   #13
Homemade WRX
Scooby Guru
 
Member#: 33782
Join Date: Mar 2003
Chapter/Region: MAIC
Location: 3MI Racing LLC
Vehicle:
96 bastard child
search FIRST, then PM!!!

Default

well, you can't really compare it to a door to well, as the seat's throat would be the door jam

it gives are larger open area. Think of it as a ring. The circumference of the valve and the distance lift from the seat. This brings about possible new flow issues with the flow possibly being impinged by a cylinder wall or part of the cumbustion chamber. With larger valves, the throat or port can become a larger factor in the ports flow restriction, if not the choke point.
Homemade WRX is offline   Reply With Quote
Old 07-05-2008, 02:12 PM   #14
Weemus
Scooby Specialist
 
Member#: 16415
Join Date: Mar 2002
Chapter/Region: BAIC
Location: East Bay in the CA
Vehicle:
02 WRX 18G-XT+E85=
WRBwhatothercoloristhere?

Default

So you don't need new seat to go +1mm in valve size?? Any machining issues at all (trim the vavle stem length?)
Weemus is offline   Reply With Quote
Old 07-05-2008, 02:26 PM   #15
Sinister redlines
Scooby Specialist
 
Member#: 120641
Join Date: Jul 2006
Chapter/Region: NWIC
Location: Port Orchard, WA
Vehicle:
05 HTA3586,BB 2.5L
CGM

Default

When I did my 1mm oversize valves it was obvious that the seats are the limiting factor due to the size. Yes, they can be ground down but I opted to just replace the seats with larger ones that where more suited to the valves. All I can say is holy crap the stock seats are very hard to machine!!!! I went through two cutters getting them out..

And yes I opened the throats up a bunch after they where changed, Cant remember the exact #'s but I have them in the shop but they where a drastic improvement on the flow bench.
Sinister redlines is offline   Reply With Quote
Old 07-05-2008, 02:34 PM   #16
Sinister redlines
Scooby Specialist
 
Member#: 120641
Join Date: Jul 2006
Chapter/Region: NWIC
Location: Port Orchard, WA
Vehicle:
05 HTA3586,BB 2.5L
CGM

Default

And yes cossie heads flow different that listed due to pressures, I measured all of mine at 25"
Sinister redlines is offline   Reply With Quote
Old 07-05-2008, 03:51 PM   #17
fwillyj
Scooby Newbie
 
Member#: 165640
Join Date: Dec 2007
Location: taylorsville Ut.
Default

-I can say this about B25 heads----when you start getting greedy on the intake ports chances are you will end up having to weld because of the thin port walls.

-The B25's intakes are getting super thin when ported to where they flow anywhere into the 270CFM range on my flowbench.

-Recently I machined both a B25 and an S20 WRX head----machined away all the outside redundant metal leaving only the absolute minimum necessary to still be able to flowtest and to still be able to do the valve seats.

-The reason I machined these heads was so that I could get to and see----and measure the port wall thickness just about everywhere.

-The S20 head has like nearly 3 times the intake port wall thickness to work with.
----------------------------------------------------------
-When companies first started building valves for the Subarus they first came out with 1/2mm oversize valves and basically held the overall length (chamber to tip) to the same as stock----and the 1/2mm valves ended up being a lot of work for such a small gain.
------------------------------------------
-If the valve head is increased in size----and the margin thickness is held the same as stock---and the overall length is also maintained at stock length then you face some issues.

-I prefer to measure the distance from the deck of the head down to the edge of the margin or a stock valve on a stock seat--establish that as a baseline depth for the new valves.

-Then I measure the tip end down to the spring shim metal of the head and get a distance--so that you know where you were as far as valve adjustment is concerned.

-when you change valve lengths this becomes an ordeal getting the followers to basecircles of the cam so that you are in the ball park for valve lash.

-If you install oversize valves that have stock overall lengths then you end up with the tip lengths being TOO LONG.
------------------------------------------------------------------------
-After the 1/2mm valves had been on the market a few years everybody figured out that 1mm valves could actually be installed onto the stock seat rings----and when porting the heads the larger intake valves became well worth the effort.

-The problem was that the valves were now way too long on the camshaft side.

-It took almost a year dealing with Willy at Supertech to understand that this was indeed a serious problem---especially before the STI followers were available---back when dealing with the "lash caps under the buckets".

-So finally Willy started getting the valves made----to shorten the stem lengths and to move the keeper grooves down the same distance as the oversize of the valve heads--which suited me just fine.
-------------------------------------------------------------------
-I have never installed oversize intake seat rings--probably never will except maybe on some special project where money is not inhibited.

-As far as machining the stock Subaru seats I find they machine very easy if the speed is 60rpm (or less).
------------------------------------------------------------------
-as far as exhaust---if you look at the 3 examples I have shown---I serious doubt that people will ever find much more flow on the exhaust than either of the "C" brand heads--at least air flow that isn't real expensive.

-And as you can see from my porting efforts on the exhaust--it is very difficult to show significance in air flow when going to oversize Supertech exhaust valves---and now that I have seen that "C" air is there I just need to figure out how to get it myself.

-maybe some other brand of valve flows better---but the only other valve I have flowtested is Ferrea---and they don't show me anything positive in any manner----in fact I would much rather deal with stock valves than any Ferrea's regardless of their size.

Last edited by fwillyj; 06-23-2011 at 10:01 PM. Reason: spelling correction
fwillyj is offline   Reply With Quote
Old 07-05-2008, 11:10 PM   #18
charliew
Scooby Specialist
 
Member#: 125304
Join Date: Sep 2006
Location: Crawford, TX.
Default

fwillyj thanks for more great info.
Because of the difference in exhaust ports my son worked really hard to improve the dogleg to flow as much as the short port. He felt that a better idea was to try to balance the cylinders as much as possible.
charliew is offline   Reply With Quote
Old 07-06-2008, 12:47 AM   #19
Sinister redlines
Scooby Specialist
 
Member#: 120641
Join Date: Jul 2006
Chapter/Region: NWIC
Location: Port Orchard, WA
Vehicle:
05 HTA3586,BB 2.5L
CGM

Default

Honestly after cutting the seats for bigger ones I found that I was able to open up the throats by 1/8" in dia.I have some pics but I will have to dig them up.. But I did have to scallop the seats in order to get it set correctly. Then I just did a light port job and found that this was the best combo. I also undercut a BC 1mm oversised intake and found no improvement in flow.
Sinister redlines is offline   Reply With Quote
Old 07-06-2008, 12:47 AM   #20
fwillyj
Scooby Newbie
 
Member#: 165640
Join Date: Dec 2007
Location: taylorsville Ut.
Default

-When I flowtested the two Cnc'd heads I didn't even pull the valves out to look at the ports-----didn't CC the ports or anything---didn't check the valve seats or the valve depths into the chambers etc----just pulled the springs off and installed my softer springs and flowed'm.

-But now that I've seen what those things flow it becomes incentive knowing the flow is sitting there waiting for me to find it.

-I almost think the valves may have been sunk down into the heads to get the flow--but I'm pretty reluctant to change my procedures much.

-I'd probably need to change my seat cutter profile on the intake---drop the valve head down into the head about .010" or so----try to talk Willy at Supertech into building me some valves with thicker margins (which I have already tried to get him to do with no success).

-The longest exhaust port responds real well to the work on the corner at the crest of the floor----but there is water right there and that is a real trick to get in there and weld the hole back up--so I stay fairly conservative in that area.

-Flowtesting one exhaust valve at a time and working on improving the flow of one valve at a time is part of what it takes to find the big flow.
fwillyj is offline   Reply With Quote
Old 07-06-2008, 11:46 AM   #21
Weemus
Scooby Specialist
 
Member#: 16415
Join Date: Mar 2002
Chapter/Region: BAIC
Location: East Bay in the CA
Vehicle:
02 WRX 18G-XT+E85=
WRBwhatothercoloristhere?

Default

So are Supertech oversize valves slightly shorter in length due to the assumption that they will be sunk in the head slightly from machining the stock seats?
Weemus is offline   Reply With Quote
Old 07-06-2008, 01:20 PM   #22
Sinister redlines
Scooby Specialist
 
Member#: 120641
Join Date: Jul 2006
Chapter/Region: NWIC
Location: Port Orchard, WA
Vehicle:
05 HTA3586,BB 2.5L
CGM

Default

Just like you said above I did recess the valves .015" and gives a little head room for the avcs and grind the stem at the bucket to make up for it. I have been using the BC stuff but I almost 99% sure they are manley reboxes. The only catch is I had to shim the spring a slight amount to get the seat preasure where I wanted it. Its a trick the V8 guys have been doing longer than I have been alive (I am in my thirties)... The trick is to unshroud the valve as much as possible, I noticed a huge change in flow charistics when using the larger seats and really opening the thoats. Enough that only a slight port work was required to get the balance ratio between the ports (exh/int) I was looking for..

Last edited by Sinister redlines; 07-06-2008 at 01:26 PM.
Sinister redlines is offline   Reply With Quote
Old 07-06-2008, 01:28 PM   #23
Sinister redlines
Scooby Specialist
 
Member#: 120641
Join Date: Jul 2006
Chapter/Region: NWIC
Location: Port Orchard, WA
Vehicle:
05 HTA3586,BB 2.5L
CGM

Default

You mentioned you had no problem cutting the seats for the valve. Yes easy enough but try machining them out = SUCKS.. Very hard seats..
Sinister redlines is offline   Reply With Quote
Old 07-06-2008, 02:48 PM   #24
Homemade WRX
Scooby Guru
 
Member#: 33782
Join Date: Mar 2003
Chapter/Region: MAIC
Location: 3MI Racing LLC
Vehicle:
96 bastard child
search FIRST, then PM!!!

Default

sinister, what balance or ratio did you aim for with your ports?
Homemade WRX is offline   Reply With Quote
Old 07-06-2008, 03:11 PM   #25
fwillyj
Scooby Newbie
 
Member#: 165640
Join Date: Dec 2007
Location: taylorsville Ut.
Default

-stock ID2 intake valves are 4.109" overall length.
-Supertech #1mm intake #SIVN-1014-2 (ce) = 4.109" OAL

-Supertech #1mm intake #SIVN-1012-2 (fd) = 4.091" OAL
-----------------------------------------------------
-stock ED3 exhaust valves are 4.120" overall length.
-Supertech #1mm exhaust (ce) are 4.106".
Supertech #1mm inconel exhaust (cd) are 4.108"

-the ce, fd & cd are imprinted onto the Supertech valves just below the keeper grooves----the ED3 and the ID2 are forged into the head of the stock Subaru valves.
---------------------------------------------------------------------------
-Personally I am not interested in doing oversize seat rings and trying to get the valves like I want'm--maybe after I see a set of heads that have had all that work done to'm----and maybe when those heads with the oversized seats and valves start showing the world that we just can't live without'm---maybe then I'll look into it.

-But if I personally owned a Subaru and a chassis dyno----and I was trying to prove all the variants of performance engines I'd for sure do at least one set just for testing and documentation.
fwillyj is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
1mm oversized valves jaxscuby Built Motor Discussion 9 11-25-2009 11:16 PM
EJ207 head flow numbers...stock vs ported vs ported and larger valves...ect.. q_dubz Built Motor Discussion 0 04-16-2009 01:58 AM
testing waters:PRo PORTED and flow tested WRX heads with 1mm + stainless valves WRXINTX Engine/Power/Exhaust 2 09-25-2006 04:37 PM
Port & Polish VS. Just Oversized Valves Carlito2002WGN Built Motor Discussion 18 08-29-2006 02:33 PM


All times are GMT -4. The time now is 03:13 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.