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2.5 head in a 2.7 on a 2.7 bottom end? lulz help me out guiz

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    #16
    Originally posted by acolella76 View Post
    You will never get the '200' casting head to flow better than the '885' head. You will probably spend over a grand just to get it close. Also, you don't HAVE to swap the harness and stuff over to make the cylinder head work, but it would be pointless not to swap to motronic 1.3.

    I think you should go full motronic 1.3/885 head swap. It's not that expensive, and it's just like changing a head gasket. I can post a dyno graph of my 2.7i if that would sway your opinion.
    never is a long time........the thing is the stock 885 has much more flow potential than the rest of the system uses so you dont need a 200/731 to flow as much to make the same or more power.

    if i had to build a performance 2.5 i would start with the 200, it is a better shape to start with just on the small side which is fixable but you are right there is a fair bit of work and money involved,.
    89 E30 325is Lachs Silber - currently M20B31, M20B33 in the works, stroked to the hilt...

    new build thread http://www.r3vlimited.com/board/showthread.php?t=317505

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      #17
      Originally posted by Pantless Spency View Post
      a cam from pnp is like 30 bucks
      I believe Mr. 325 has head building experience so hopefully he'll jump in if I'm wrong, but I believe you need special tools to pull a cam or else you'll risk breaking it because it's hollow.

      So whatever else you decide to do, don't go yanking cams out of the PnP willy-nilly.
      Das ist nicht nur nicht richtig, es ist nicht einmal falsch!

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        #18
        also just to be clear this will lower your compresssion ratio right?

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          #19
          Originally posted by digger View Post
          if i had to build a performance 2.5 i would start with the 200, it is a better shape to start with just on the small side which is fixable but you are right there is a fair bit of work and money involved,.
          This is totally true, you can open up the 200 head just as big or bigger than the 885 cylinder head. My buddy Myster-e is working on one right now for out project E30. We'll be drilling out the oil holes to run a reground i camshaft and opening it up to fit the bigger i valves as well. Once it's all done I'll post results. We're rebuilding an Eta bottom end for it to go on to. It's going to be a true 9:1 2.7i engine.

          Originally posted by smooth View Post
          I believe Mr. 325 has head building experience so hopefully he'll jump in if I'm wrong, but I believe you need special tools to pull a cam or else you'll risk breaking it because it's hollow.

          So whatever else you decide to do, don't go yanking cams out of the PnP willy-nilly.
          If you break a cam while removing it you've got some serious issues. To remove the camshaft you'll need to pull the rocker clips, rocker shafts, and rocker arms.

          Originally posted by bastianshaw View Post
          also just to be clear this will lower your compresssion ratio right?
          The 885 head on the Eta bottom end is roughly 8:1 compression whereas the Eta originally is 9:1 compression and the i engines are 8.8:1 compression. The 885 head swap on the Eta bottom end CAN make decent power though, it helps to have a port/polished head and a mild cam.
          BimmerHeads
          Classic BMW Specialists
          Santa Clarita, CA

          www.BimmerHeads.com

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            #20
            How much is this swap roughly with a port and polished head and cam?

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              #21
              Originally posted by smooth View Post
              I believe Mr. 325 has head building experience so hopefully he'll jump in if I'm wrong, but I believe you need special tools to pull a cam or else you'll risk breaking it because it's hollow.

              So whatever else you decide to do, don't go yanking cams out of the PnP willy-nilly.
              Lol I've already got my cam out. It's perfectly intact :)

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                #22
                Originally posted by MR 325 View Post

                If you break a cam while removing it you've got some serious issues. To remove the camshaft you'll need to pull the rocker clips, rocker shafts, and rocker arms.

                Yup, it's the 24v cams that you have to worry about breaking. With these heads the spring isn't putting direct pressure on the cam while you pop bearing caps off. Instead it just slides out of the front of the head after you take the rockers and rocker shafts out.
                -Alex

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