M20B28 Engine Build

9 thoughts on “M20B28 Engine Build

    1. Hi Roberts, I’ve added the crank spacer diagram to the gallery above (last image). It is sources from e30zone.net. I used to as the base but sorted out the final details when I turned the piece on the lathe.

      Thanks, Patrick 🙂

        1. Hi – I used the stock M20B25 pistons from a 1988 model. They are short skirt type. If you use early model pistons the the skirts get in the way of the conrods.

  1. Patrick I’m lost in details,but can you tell me one thing? The engine block you used in your m20b28 is it from a 2 liter M20B20? Or a bigger 2.5 liter m20b25? I find amazing that a m52b28 crankshaft would fit an M20B20 or b25 block. I am very curious because I would love to increase the cc in my M20B20 wich currently “lives” in a 1990 E34 520i. Thank you!

    1. Hi, the block is from an M20B25, as are the pistons. The conrods are from the M20B20 – they are a little bit shorter than the M20B25 ones. All that’s needed to make M52B28 (non-VANOS) crank fit is a spacer for the front of it. You need to check piston skirt clearance too – some of the earlier M20B25 pistons have longer skirts.

      I believe it is possible to use the crank from an M54B30 but that’s needs custom conrods and pistons. Each BMW 6 cylinder is a futher development of the previous generation so there tends to be some compatibility between them.

      Thanks Patrick

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