Piston and Ring differences between Contessa/Corsa

[johnny248]

According to Polini, the Contessa and Corsa kit use different pistons and rings.

Contessa Piston 206.0680
Corsa Piston 206.0690

Contessa Rings 206.0200 x2 ( same top and bottom ring)
Corsa Rings Top 206.0201 Bottom 206.0200 (same bottom as Contessa)

I see the Corsa uses a chrome top ring and shares the same lower ring as the Contessa.

What is different about the pistons? A couple of sellers state that the Corsa piston is graphite coated and it does not mention this about the Contessa. Well, I can tell you for a fact that the Piston in my factory sealed Polini box is not graphite coated at all. That being said , I wouldn't know what is different.

[patthesoundguy]

I love these kinds of questions. It can lead to great cross references for parts when the original might not be available.

[1man8scoots]

Polini is out of production of the graphite coated pistons but has neglected to update the box. Many manufacturers do this. Fabrizi, stage 6, polini, and hebo are all brands I've found inaccuracies in their cylinder kits contents. I tried to get a coated piston but was told nla. The coating does not last long anyways, it's more for break in.

[1man8scoots]

Shiny ring on top, dull scraper ring on bottom. There's really no reason for the shiny ring besides less drag. They seem to be more brittle after time. Maybe someone has more knowledge on the tensile strengths between the two.

[1man8scoots]

They're listed different but the pistons are the same part number in the boxes. The first few corsa kits I used years ago were distinctly more dull grey and had the feel of graphite coating. All in all I never noticed a difference when they transitioned.
I may have one of the old pistons laying around. I'll look later on and if so send it to you with the naraku cylinder.