The 1.9 liter piston had a larger compression height (wrist pin further from the top) than the 2.1 liter (wrist pin closer to the top). This was because the crankshaft stroke (also known as “throw”) was 7mm (piston travels 3.5mm further up and 3.5mm further down) longer on the 2.1 than on the 1.9 (76mm instead of 69mm, respectively), so the wrist pin had to be moved 3.5mm closer to the top of the piston. The dish at the top of the pistons were also totally different in both volume and shape. The 2.1 having a much more advanced design.
