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I cam in eta head or 885 head on eta engine questions

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    I cam in eta head or 885 head on eta engine questions

    After some autocross and spirited summer driving, I am looking for a little bit more power. And before I begin, I don't want to take on an engine swap. I am looking to make some smaller changes that give respectable gains and don't require long periods of downtime for the car, since it is my dd. I know a stock m20b25 will be more powerful, but for a variety of reasons, I am not looking to do a full engine swap.

    What I am looking at is an upgrade plan that will not require much down time, with different steps that can be spread out if need be.

    I am considering doing three things:

    1- Drill the oil passages in the journals and install an i cam and dual valve springs in a spare eta head, and match port the intake and exhaust ports to the i components, then, swap the head. The actual head swap should take an afternoon at most.

    2- Convert from motronic 1.0 to 1.3, along with a 2.5L intake, throttle body, and i tach. I already have a complete I exhaust installed. I figure this process would take a day, or at most, a weekend to complete. Ideally, however, I would do it concurrently with the head swap.

    3- Swap dual mass to single mass flywheel and install a taller limited slip rear end. Either of these steps can be done whenever I have the time/money for it.

    I don't want to undergo a complete m20b25 swap, due to the time and amount of parts necessary. If I was going to do a complete one shot engine swap I would do an m30 or m50. I just don't have the time for a job like that right now, so my options are: motronic 1.3 with either an eta head with i cam, a 323 head, or an 885 head. From what I have read the gains between the eta and the 323 head are negligible. It looks like the size different in valves is minuscule. I have no intention of adding boost. That leaves me with the option of an 885 head or an i cam in an eta head.

    Can anybody who has actual hands on experience with these swaps (keeping it limited to stock components; no megasquirt, straight pipes, one off chips, custom pistons, etc) weigh in? I know there are tons of threads on these options, but there is way too much "so and so said it was amazing" or "so and so said it will never run right" in them. Its hard to get a straight story with so much contradiction. I know this is not going to make a fire breathing monster, but as I understand it, there are gains to be had, and considering how cheap the parts are, it seems worth it.

    Have you done this swap and been entirely underwhelmed, or worse? Is it a waste (as in, there was no improvement)?

    What would be the best final drive? Is a 3.25 too short with the increased 6.7k redline? Is 4.10 too tall?

    Is the dual to single mass flywheel swap worth it? With 230k on the car, I am fairly certain I can benefit from a new clutch regardless.

    Please, let me hear your constructive thoughts. I know what the options are. I have read all sorts of contradicting second hand thoughts from people. I want to hear first hand knowledge and experience of this swap.
    19
    200 head: higher compression
    0.00%
    0
    885 head: larger valves
    100.00%
    19
    Last edited by Andy.B; 05-23-2013, 07:39 PM.

    #2
    An I cam in an ETA head with I springs is not a viable solution. The ETA head doesn't have the lubrication for the additional cam journals, the head won't flow enough to take advantage of the cam, and the intake/TB is also a problem.

    A budget stroker (I head, intake/TB, AFM, injectors, AFM, CPS, engine harness, & DME) will make a bit more power than the stock ETA and would be an improvement. As would using the I single mass flywheel (with the appropriate throwout bearing).

    As to the differential, a 3.73 is the best all around ratio. A 4.10 will give better low speed acceleration, but reduced fuel mileage and higher engine speed on the highway.
    The car makes it possible, but the driver makes it happen.
    Jim Levie, Huntsville, AL

    Comment


      #3
      Originally posted by jlevie View Post
      An I cam in an ETA head with I springs is not a viable solution. The ETA head doesn't have the lubrication for the additional cam journals, the head won't flow enough to take advantage of the cam, and the intake/TB is also a problem.
      10 years ago, everyone was parroting the exact opposite opinion. People used to say that the 885 head's compression loss meant it was not a viable option, and to go with the I cam in the eta head. Popular opinion has changed, but I have yet to see an apple to apple comparison between the two builds.

      I have looked around and been unable to find it, but I would love to see dyno graphs comparing the two builds (that is, 200 or 885 head casting on 2.7 block, with everything else being equal).

      As for the 885 head being a better option, I see that stated often, but when my options are to take a minor hit in valve size and sacrifice some top end power (40/34 for an eta, and 42/36 in an i) or take a hit in compression that will hurt power across the board, the eta head sounds like a better option.

      (I did forget to mention in my first post, but I am aware that I will need to get the journals of a 200 casting head drilled for a 7 bearing cam. Also, I planned on swapping the throttle body and intake. I edited my first post to reflect that.)

      Comment


        #4
        I guess what this question all comes down to is which is better: bigger valves (885 head) or higher compression (200 head)?

        Comment


          #5
          I also have a question on this subject, who here has actually cut the square body harness and spliced the round one on? What problems? What extra wires? What missing wires? I have done extensive searching and every one I found was done on a late 86 or newer, or there was not info given.

          Comment


            #6
            Originally posted by Andy.B View Post
            I guess what this question all comes down to is which is better: bigger valves (885 head) or higher compression (200 head)?
            go ahead and drill new journals and get double valve springs then. The 885 head with 2.7 block has been proven as the easiest power increase. Pretty sure dynoed at 145 whp and 150 wtq.
            2014 Alpine White 335i MSport
            (Daily Driver)
            Full Mperformance Aero

            2007 Black Sapphire Metallic E92 335i (6MT)
            KW V2 Coilovers
            VRSF Catless Downpipes

            Comment


              #7
              Originally posted by codyep3 View Post
              go ahead and drill new journals and get double valve springs then. The 885 head with 2.7 block has been proven as the easiest power increase. Pretty sure dynoed at 145 whp and 150 wtq.
              I am not convinced of which is better. I just find it interesting that in the past, everyone claimed the 200 was a better head for an eta bottom end, and now, most claim that the 885 is the better option.

              What I am looking for is feedback from people who have actually done either swap, or better yet, feedback from someone who has experience with both. I am hoping for firsthand accounts and data of what the results are, not just hearsay.


              If no one can actually speak to experience with both, I may do it myself. It looks like I can replace a head gasket and bolts for under $100 in parts.

              Comment


                #8
                because it is easier to slap on a 885 head and call it a day. Why get the cam journals drilled and put 325i double springs on, when I am sure you can get practically the same numbers with that of the 885 head. People generally do a 2.7i with plans of forced injection. Low CR makes it safer and worry free.
                2014 Alpine White 335i MSport
                (Daily Driver)
                Full Mperformance Aero

                2007 Black Sapphire Metallic E92 335i (6MT)
                KW V2 Coilovers
                VRSF Catless Downpipes

                Comment


                  #9
                  the loss in power from compression is small TBH (you arent talking a 2.0 change).
                  if you properly ported the 200 (or 731) it would be a better option and have correct squish (piston matching head).
                  100% stock the 200 or 731 head have never shown decent power.

                  A SETA with I-cam is better than the ETA with an I-cam due to the matched piston and chamber FWIW but still anything with a stock 200 is rubbish
                  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

                  Comment


                    #10
                    Or.... getting the 885 head decked to bump up some of the lost compression... anyways thats what I did. Car pulls great and by far quicker than a eta or stock 325i.

                    Comment


                      #11
                      Originally posted by e30trooper View Post
                      Or.... getting the 885 head decked to bump up some of the lost compression... anyways thats what I did. Car pulls great and by far quicker than a eta or stock 325i.
                      this would work even better on a SETA bottom than a ETA since then the squish clearance moves into the sweet spot
                      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

                      Comment


                        #12
                        I decided to follow the overwhelming vote for an 885 head, and am going to perform the swap when my car comes back from paint. I decided to get the head shaved to the minimum spec, and am going to use an adjustable cam gear to correct the timing (if necessary).

                        Thanks for the input everyone.

                        Comment


                          #13
                          I decided to get the head shaved to the minimum spec
                          I am looking at doing this swap as well, what is the minimum spec for shaving the head? What is the difference in CR from doing it?

                          Thanks

                          Comment


                            #14
                            When I was running ideas for an m20 build several months ago I was planning on using an 885 head on an ETA block but still retain the ETA cam by using set screws to block the additional oil journals. The 885 head allows for more intake and exhaust flow and paired with a chip on the stock ETA ecu makes a ton of low end torque reving to about 6k.

                            You can get a general idea of what I had planned here...


                            Now, however, I am going with a built up 2.8 stroker.

                            Good luck with your plan!
                            À la folie

                            Comment


                              #15
                              getting the 885 head decked
                              that's where I was headed...

                              t
                              now, sometimes I just mess with people. It's more entertaining that way. george graves

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