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    • How Porsche is getting 4.0 liters out of the 9A2B6 engine architecture for the 2020 718 Spyder and Cayman GT4

      You may have noticed Porsche went from 3.0 liters turbocharged to 4.0 liters naturally aspirated with the 9A2B6 engine design for the new 718 Boxster Spyder and Cayman GT4 models. They designed the motor with this modular flexibility in mind.


      PorscheBoost previously discussed that this architecture can be taken to eight cylinders if necessary:

      9A2 Engine

      Cylinders: 4
      Bore x Stroke: 91mm x 76.4mm
      Displacement: 1987cc

      Cylinders: 4
      Bore x Stroke: 102mm x 76.4mm
      Displacement: 2497

      Cylinders: 6
      Bore x Stroke: 91mm x 76.4mm
      Displacement: 2981cc

      Cylinders: 8
      Bore x Stroke: 91mm x 76.4mm
      Displacement: 3975cc

      Cylinders: 8
      Bore x Stroke: 102mm x 76.4mm
      Displacement: 4994cc


      What Porsche did for the 9A2B6 4.0 is use the 102mm bore from the 718 S 2.5 models and they increased the stroke to 81.5mm. The result is 3995.8cc.

      In theory this means when we start seeing built motor 9A2B6 3.0 applications adding up to a liter of displacement will not be a problem. Increasing bore alone will take you to 3.8+ liters.

      Porsche provided plenty of flexibility for this engine design to grow which in turn gives some Porsche enthusiasts engine building headroom.

      This article was originally published in forum thread: How Porsche is getting 4.0 liters out of the 9A2B6 engine architecture for the 2020 718 Spyder and Cayman GT4 started by Sticky View original post
      Comments 4 Comments
      1. Bowser330's Avatar
        Bowser330 -
        so the current 991.2 Carrera 3.0T can be bored out to to a 911 turbo matching 3.8L when itís time to build the engine, nice.
      1. KEMA's Avatar
        KEMA -
        Or the other way around? Slap a couple of OEM GTS turbos on the 4.0?
      1. Sticky2's Avatar
        Sticky2 -
        Click here to enlarge Originally Posted by Bowser330 Click here to enlarge
        so the current 991.2 Carrera 3.0T can be bored out to to a 911 turbo matching 3.8L when it’s time to build the engine, nice.
        Bingo
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by KEMA Click here to enlarge
        Or the other way around? Slap a couple of OEM GTS turbos on the 4.0?
        Would be a huge pain in the rear to make it work. The Boxster/Cayman don't have enough room and it's not worth putting the motor in the 911.