m52b25 or m52b28?! no way of knowing

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • Dirtnap30
    Member
    • Aug 2011
    • 58

    #1

    m52b25 or m52b28?! no way of knowing

    ok so this is beginning to drive me nuts. I recently swapped an m52 into my car and its been running strong. however my issue is that I have no real way of telling if its a 2.5 or 2.8. I never saw the car it came out of (sat in my bosses storage container for like 3 years, claims it came out of a 94' 325i....obviously wrong, clearly an obd2 motor) but anyways, the badge on the block is not readable and I NEED to find out cause I'm running a 3.0l turner tune which turner claims is ok for a 2.8. any suggestions?
  • pandaboo911
    R3VLimited
    • May 2010
    • 2070

    #2
    There should be a piece of the headgasket that sticks out past the block that lists displacement. It's on the exhaust side next to the vanos

    Comment

    • 328ijunkie
      Forum Sponsor
      • May 2007
      • 3961

      #3
      Stamp on drivers side of block

      Check Us out on Facebook
      Needing a harness adapter or wiring help? Check it out: also have 24v motor mounts, E30 M3 covers and E36 ECU mounts!
      Full Product Line Tuning
      OBD2 Tuning Available! OBD2 E36, S54 Swap, S62 Swap, etc: tuning@MarkertMotorWorks.com Dyno Thread

      Comment

      • Dirtnap30
        Member
        • Aug 2011
        • 58

        #4
        I've yet to been able to clean the block tag up enough to even read a single digit :(

        Comment

        • Dirtnap30
          Member
          • Aug 2011
          • 58

          #5
          Originally posted by pandaboo911
          There should be a piece of the headgasket that sticks out past the block that lists displacement. It's on the exhaust side next to the vanos
          just confirmed it, says 2.5 :sad: not stoked right now. I should probably get a new tune asap

          Comment

          • DesertBMW
            E30 Enthusiast
            • Aug 2011
            • 1011

            #6
            Originally posted by Dirtnap30
            just confirmed it, says 2.5 :sad: not stoked right now. I should probably get a new tune asap
            That is not correct way of knowing because all 2.8 head gaskets will have 2.5L on them, even the cylinder heads.

            You got to look at the driver side right by the engine mount on the bottom of the block it will say 28 s 01 if its 2.8l

            Or take one of the spark plugs out and use long screw driver and measure the stroke, 2.8L will have 84 mm stroke.

            Comment

            • DesertBMW
              E30 Enthusiast
              • Aug 2011
              • 1011

              #7
              Originally posted by pandaboo911
              There should be a piece of the headgasket that sticks out past the block that lists displacement. It's on the exhaust side next to the vanos
              This is wrong information, 2.5L and 2.8L share the same head gasket and gaskets are all marked as 2.5L

              Comment

              • 328ijunkie
                Forum Sponsor
                • May 2007
                • 3961

                #8
                ^That.

                Take a plug out and put an extension in the plug hole. Measure the stroke while rotating the crank.

                2.95" = 2.5L
                3.31" = 2.8L

                Check Us out on Facebook
                Needing a harness adapter or wiring help? Check it out: also have 24v motor mounts, E30 M3 covers and E36 ECU mounts!
                Full Product Line Tuning
                OBD2 Tuning Available! OBD2 E36, S54 Swap, S62 Swap, etc: tuning@MarkertMotorWorks.com Dyno Thread

                Comment

                • eurosport22
                  Wrencher
                  • Jan 2012
                  • 210

                  #9
                  damn i would have made sure i knew all that before i put the motor in. but hopefully you ended up with a 2.8

                  Comment

                  • Dirtnap30
                    Member
                    • Aug 2011
                    • 58

                    #10
                    I'm gonna measure the stroke asap and pray its not a 2.5....

                    Comment

                    Working...