Jump to content


Welcome to Ultimate Subaru Message Board, my lurker friend!

Welcome to Ultimate Subaru Message Board, an unparalleled Subaru community full of the greatest Subaru gurus and modders on the planet! We offer technical information and discussion about all things Subaru, the best and most popular all wheel drive vehicles ever created.

We offer all this information for free to everyone, even lurkers like you! All we ask in return is that you sign up and give back some of what you get out - without our awesome registered users none of this would be possible! Plus, you get way more great stuff as a member! Lurk to lose, participate to WIN*!
  • Say hello and join the conversation
  • Subscribe to topics and forums to get automatic updates
  • Get your own profile and make new friends
  • Classifieds with all sorts of Subaru goodies
  • Photo hosting in our gallery
  • Meet other cool people with cool cars
Seriously, what are you waiting for? Make your life more fulfilling and join today! You and your Subaru won't regret it, we guarantee** it.

* The joy of participation and being generally awesome constitutes winning
** Not an actual guarantee, but seriously, you probably won't regret it!

Serving the Subaru Community since May 18th, 1998!

Guest Message by DevFuse
 

Photo
- - - - -

EA82 cylinder head question


  • Please log in to reply
6 replies to this topic

#1 abog

abog

    USMB is life!

  • Members
  • 192 posts
  • reno

Posted 25 February 2009 - 08:38 PM

Does anyone know the changes that were made to the three generations of heads for the EA82 ?

#2 GeneralDisorder

GeneralDisorder

    Elite Master of the Subaru

  • Members
  • 20,280 posts
  • Portland

Posted 25 February 2009 - 09:26 PM

I assume you are refering to the three generations of EA82 *turbo* heads? To my knowledge there were only a single generation of non-turbo, single port heads made.

They were made succesively thicker in the area of the exhaust ports to prevent cracks between the valves extending into the coolant jacket. The problem was never adequately solved and only by controlling the mixtures to prevent excessive exhaust gas temps and limiting the level of forced induction to about 12 pounds or less are they capable of holding. Eventually the engine was outmoded by the EJ20T and attempts to solve the problems of the EA82T beyond 175 HP were abandoned.

Further, the last (third) generation of heads were never actually put into production engines. They were only availible through the parts channels.

GD

#3 abog

abog

    USMB is life!

  • Members
  • 192 posts
  • reno

Posted 25 February 2009 - 09:29 PM

So I can assume that they all flow the same? Thanks GD

#4 GeneralDisorder

GeneralDisorder

    Elite Master of the Subaru

  • Members
  • 20,280 posts
  • Portland

Posted 25 February 2009 - 09:42 PM

If anything I would say the earlier gen heads might flow more due to there being less material. But overall I've never heard of anyone noting a difference. There's no indication of that from Subaru either as there was never anything put out about not mixing them if the need arises. Also the valves are all the same sizes and that is likely to be your limiting factor more than the port dimensions. Porting and polishing can yeild some improvements with less turbidity in flow, but is unlikely to flow more CFM without a change in the valves themselves.

GD

#5 subiemech85

subiemech85

    SIX STAR SERVICE

  • Members
  • 2,710 posts
  • down by the river

Posted 25 February 2009 - 10:11 PM

attempts to solve the problems of the EA82T beyond 175 HP were abandoned. GD


so, how did they solve the porblems up to 175 hp? :burnout:

#6 GeneralDisorder

GeneralDisorder

    Elite Master of the Subaru

  • Members
  • 20,280 posts
  • Portland

Posted 25 February 2009 - 10:20 PM

so, how did they solve the porblems up to 175 hp? :burnout:


They had access to parts that we do not and they designed the thing in the first place. Careful mixture control, timing, and boost settings via custom ECU programming. They also increased the RPM quite a bit.

Mind you I'm refering to the european rally race versions that semi-reliabily produced around 175 HP. That is not to say this did anything good for the engine life (it didn't), and it's also not to be intended as a hard limit to the HP the engine can make. It can make more - it just won't last very long. The EA82 engine was designed on paper - a stop-gap solution till the EJ engine was ready. It's an EA81 with overhead cams - nothing more. It does not have the crank stability, nor the head, head gasket, or mating design stability for high-rpm/hp applications. The EJ20T was computer designed from the outset for turbo-charging. It produced over 200 HP in it's first variation in the late 80's.

GD

#7 Loyale 2.7 Turbo

Loyale 2.7 Turbo

    The Mighty "BumbleBeast"

  • Members
  • 5,740 posts
  • Roatán, Honduras.

Posted 26 February 2009 - 01:08 AM

I Agree, Absolutely.

...the last (third) generation of heads were never actually put into production engines. They were only availible through the parts channels. ...


I Guess That`s Why the Newer Heads for EA82`s at the Dealer, came Heavier and the EGR Passages Comes Closed!




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users