The interest of the Porsche engine is that the architecture of some engines is partly identical from 1963 to 2012 with parts and can be mounted in one and the other, we can put a 1963 crankshaft in a GT3 by increasing the diameter of the crankshaft bearings, there has always been 118 mm between each cylinder and the same space between the right and left cylinder bases as well and that for the cylinder head gasket plant is why at Porsche almost everything is allowed to make 2.0/ 2.1/ 2.2/ 2.3/ 2.4/ 2.5/ 2.7/ 2.8/ 2.9/ 3.0/ 3.2/ 3.3/ 3.4/ 3.5/ 3.6/ 3.8/ 3.9 liter with different crankshaft of 66 mm/ 70.4 mm/ 74 mm / 76 mm of displacement, each time the crankshaft has more displacement, the connecting rods are shorter.
Nowadays, it's difficult to determine the displacement of some Porsches by simply lifting the rear hood; a 2.0 L engine can have the same external dimensions as a 3.9 L in a 2.0 L air-cooled car.
Personally, I made 2.65 liters with a 66 mm 2.0 L crankshaft and a 2.8 RSR cylinder.
