96 mm cylinder question, Difference between 1.7- 2.0? Options

[Jgilliam914]

I was digging through a storage tote and found a set of NPR 96mm pistons and cylinders.
Is there a difference between one that fits a 1.7 vs a 2.0?

[Dave_Darling]

If you measure the rods end to end, they are the same length or pretty close to the same length. If you measure from the center of the journal to the center of the wrist-pin hole, the 2.0 rods are 2.5mm longer. The 2.0 rod journals are smaller diameter, but with the center of the journal moved outward by the same amount as was cut off.

The 2.0 pistons have a different wrist pin height, AFAIK, to compensate for this.

Note that the 96mm barrels that fit into 1.7 heads are thinner than those that fit in 1.8 or 2.0 heads. The registers where the cylinders fit in a 1.7 are 100mm, leaving only 2mm thickness for the barrel at the top. The registers for 1.8 and 2.0 heads are 105mm, leaving 4.5mm thickness for the barrel. Generally the thicker one is better.

--DD