Welcome to the North American Subaru Impreza Owners Club Thursday March 28, 2024
Home Forums Images WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
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.







* As an Amazon Associate I earn from qualifying purchases. 
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 03-27-2020, 04:08 PM   #1
enduroxt
Scooby Newbie
 
Member#: 310796
Join Date: Feb 2012
Location: UT
Vehicle:
05 obxt

Default ED3 vs ED4 exhaust valves -- what are the diff?

I have an interesting situation where I have ED3 valves installed on one head and ED4 on the other (B25 heads).
The FSM states that oem valves are sodium filled. Simple question: what are the difference between ED3 and ED4 valves?
* Registered users of the site do not see these ads.
enduroxt is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 04-08-2020, 01:55 PM   #2
Homemade WRX
Scooby Guru
 
Member#: 33782
Join Date: Mar 2003
Chapter/Region: MAIC
Location: Milton Keynes, UK
Vehicle:
96 3MI Racing
search FIRST, then PM!!!

Default

I'm actually curious but I don't know. I don't often play with OEM valvetrain.
Homemade WRX is offline   Reply With Quote
Old 02-17-2021, 08:33 PM   #3
Scargod
Scooby Specialist
 
Member#: 260314
Join Date: Oct 2010
Chapter/Region: NESIC
Location: S central CT, New England
Vehicle:
2007 STI
silver gray metallic

Default

Quote:
Originally Posted by enduroxt View Post
I have an interesting situation where I have ED3 valves installed on one head and ED4 on the other (B25 heads).
The FSM states that oem valves are sodium filled. Simple question: what are the difference between ED3 and ED4 valves?
Oh, yeah, your ID says '05 OBXT. I was wondering what car/engine.
I can't see how this is helpful. Heads aren't alike? Are the ED3 or ED4 sodium-filled?
Scargod is offline   Reply With Quote
Old 02-17-2021, 10:57 PM   #4
enduroxt
Scooby Newbie
 
Member#: 310796
Join Date: Feb 2012
Location: UT
Vehicle:
05 obxt

Default

I am pretty sure the ED3 valves are sodium filled as they cost like 60$ a piece, while the ED4 valves are most likely not (20$ a piece) and a little difference in weight.
IIRC, Subaru switched to ED4 at one point for most turbo EJ engines.
As for me, I just kept the ED3s on one head and the ED4s on the other. My engine was like that most likely as a result of a partial head rebuild before I purchased the car.
enduroxt 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

All times are GMT -4. The time now is 05:47 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2024 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.

When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission
Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.