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Old 10-15-2014, 09:27 PM   #251
mofoSTI
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P&L advertises their heads as the best flowing of all aftermarket heads. 3 grand with core exchange ain't bad. They will be on my next build. I'm willing to bet they don't flow more than Cosworth heads. What do you think they do to make their heads flow better?
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Old 10-20-2014, 11:29 AM   #252
charliew
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Default flowing heads

I would read up on flowbenches so you are aware of the ways porters rate their heads on airflow. Flowbenches are like gun barrels they all are a little different. The only way to know how much improvement a specific port is improved is to flow it on the same bench before and after the porting on the same day. Check how much is lost on na flow at low lift and how much is gained at high lift. Low lift on na is whats important before boost comes up for street use. Boost really just pushes through a bigger port but that is still important as pushing through a smaller port makes more heat. Only flowing the two competing ports on the same bench will show whats really what. All intake ports need to be as close to each other as possible, that's the same with exhaust ports. The exhaust are the hardest to equalize on the suby. When ports are of different flows the af ratio will vary and it will be harder to tune each cylinder as usually only the exhaust temp on each port is available to monitor.

Last edited by charliew; 10-20-2014 at 11:49 AM.
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Old 10-24-2014, 01:09 AM   #253
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Quote:
Originally Posted by FuJi K View Post
USDM WRX D25 vs JDM STI Ver5
The USDM is the smaller wound and taller valve spring.




Do you know what the open and seat pressure difference is?


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Old 10-24-2014, 01:13 AM   #254
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Quote:
Originally Posted by charliew View Post
I would read up on flowbenches so you are aware of the ways porters rate their heads on airflow. Flowbenches are like gun barrels they all are a little different. The only way to know how much improvement a specific port is improved is to flow it on the same bench before and after the porting on the same day. Check how much is lost on na flow at low lift and how much is gained at high lift. Low lift on na is whats important before boost comes up for street use. Boost really just pushes through a bigger port but that is still important as pushing through a smaller port makes more heat. Only flowing the two competing ports on the same bench will show whats really what. All intake ports need to be as close to each other as possible, that's the same with exhaust ports. The exhaust are the hardest to equalize on the suby. When ports are of different flows the af ratio will vary and it will be harder to tune each cylinder as usually only the exhaust temp on each port is available to monitor.

If you could find out the CSA's you might be able to calculate what CFM the heads flow after porting and also are we talking hand porting or CNC? Also, air isn't pushed, the turbo compresses the molecules making the air more dense. A ported head allows more air to be able to be sucked into the cylinder while the valves are open.


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Old 10-27-2014, 10:33 AM   #255
charliew
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funny you start out showing what you have read but then mention sucked. Air is moved by flowing from a higher pressure area to a lower pressure area not from being sucked from what I have read. Also cnc is not a science it is just doing a machining operation from a program and yes it does all the same heads pretty much exactly the same but that only means they are the same, and maybe not ported the best. Cnc does not guarantee the ports will be equal in flow. And I know from the little porting my son and I have done and flow tested that the low rpm and low lift flowing is better on a smaller port.

Last edited by charliew; 10-27-2014 at 10:41 AM.
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Old 10-30-2015, 11:11 PM   #256
FuJi K
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I came across these unexpectedly.



Mission to replicate: success.
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Old 11-01-2015, 10:19 AM   #257
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I have no idea what the significance is of the upper picture. Please excuse my ignorance and the elaborate Fuji
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Old 11-01-2015, 02:23 PM   #258
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Looks like he deshrouded the bowl a bit to match?
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Old 12-15-2015, 10:59 PM   #259
FuJi K
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Quote:
Originally Posted by wrxhard View Post
I have no idea what the significance is of the upper picture. Please excuse my ignorance and the elaborate Fuji
They aren't the head casting. Top picture is that one particular head with that port style. The bottom is a small port slightly enlarged to match. You can see the left port of the bottom head that I didn't work on yet.
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Old 03-13-2018, 10:56 AM   #260
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Dragging this back up from the dead a little - but got what is allegedly a JDM non-AVCS EJ205 and the ports aren't like what I've seen before.

https://i.imgur.com/r9w6Tnt.jpg?2

USDM EJ205 with 3/4" socket

https://i.imgur.com/aqzYQ9r.jpg?1

JDM EJ205(?) with same socket

https://i.imgur.com/XxlQd4T.jpg?1

No socket. Port divider definitely doesn't extent up the port like the USDM 205s that I've seen, obviously ports are bigger too. No AVCS, came with coil-on-plug. Anyone seen one of these before?
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Old 03-14-2018, 11:02 PM   #261
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What is the casting code? Usually a single letter (S, W, B, D, Z, etc) and two digits for displacement (20 = 2.0L, 25 = 2.5L, etc).

Also emailed you about the cam profiles.

Last edited by Homemade WRX; 03-14-2018 at 11:28 PM.
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Old 03-15-2018, 02:58 PM   #262
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Heh, we keep pinging each other in different threads. Emailed you back about a couple things.

I'll look more closely but the "LH B" was the only one I saw quickly.
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Old 03-15-2018, 08:24 PM   #263
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Yeah, literally just "LH B" and "RH B".
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Old 03-25-2018, 08:15 PM   #264
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More weirdness - shimmed buckets. I wonder what the heck this came out of.
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Old 09-07-2018, 07:20 PM   #265
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Thought I had the other day - I wonder how much meat there is around the ports on an S20 head.

WIP

https://i.imgur.com/ZNK2kFU.gif
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Old 08-30-2019, 12:07 PM   #266
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Can somebody tell me if these are so called big port JDM heads?
Taken out of GC8 not sure which year EJ207 non-AVCS engine.



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Old 08-30-2019, 01:10 PM   #267
FuJi K
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Quote:
Originally Posted by Shylight View Post
Can somebody tell me if these are so called big port JDM heads?
Taken out of GC8 not sure which year EJ207 non-AVCS engine.



Yes. Difference is no AVCS.
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