GS piston in Pinasco 225cc

[morbin]

Hi all,

has anyone tried this combo with GS 69mm piston yet?

Gruss,

Matt

[Phantomias]

Ciao,

the GS Piston has normally a diameter of 68,92-68,93mm. So it depends on your Pinasco if the Cylinder- Piston Clearance is ok. It has to be also a niclasil coated Pinasco an not a chromed one. If you get a new niclasil coating I´m sure it will work.

The down side of the piston is its weight and that you have to make modifications to get a proper transfer flow.

The plus could be the ring and a better stabitity.

I´m also searching for a good 69mm Piston because my Mahle Pinasco piston has cracks. By the way: did anyone have this cracking problem on a Mahle piston (slightly modified for the 2 carb Pinasco)?

ciao

Hannes

[highko]

The real problems are in my opinoin:

Pistonrings: Made for gray cast Iron an will not work quit good with nicalsil, crom i'm not sure...

Piston itself: the thermal extension of an piston, build vor Aluiminum Cylinders is higher than one build for grey cast iron.

Wenn you wanna have the right "Kolbenspiel" when the kit has it's operating temperture, the "Kolbenspiel" of the cold cylinder might be critical, too small.

I woudn't do this, the other way round, like Mallossi Piston (for Alu Cylinder) in Polini cast iron cylinder ist the easier way....

Please excuse my 'not so good' english

Heiko.

[undis racing team]

kolben spiel:

piston clearence

[Phantomias]

Ciao,

according my informations the chromed ring is ok for niclasil. The piston clearance problems which mentioned highko are interesting.

Maybe it would be better to switch to the wiseco piston for the Kawasaki kdx 220 (d69), but I don`t know the pin positions of this piston. You`ll also have to do some modifications because this piston has a different compression height.

ciao

Hannes

[Olli ETS]

The ring(s) are not the problems.

Chromed rings can be used in cast iron or nicasil plated cylinder, but NOT in chrom plated cylinder.

There the rings and the coating tends to seize.

What can be a possible problem is the different shape of a piston for cast iron and aluminium.

A piston for aluminium cylinders has a more slim shape, a piston for cast iron cylinders a more convex shape.

Means if you use a piston for cast iron cylinders in an aluminium cylinder, the piston has in the upper part more clearance.

What also can be a problem is the clearance, I don't know the exact diameter of your Pinasco cylinders.

If the diameter is really 69,00mm, the clearance can be ok but noone can garantee you that, please measure.

Cheers Olli

PS:

The GS 177 is used by one of the GSF in a Pinasco 177 cylinder ,but I forget the name...

Maybe he has some feedback?

[gravedigger]

The GS 177 is used by one of the GSF in a Pinasco 177 cylinder ,but I forget the name...

Maybe he has some feedback?

simmerl

[morbin]

So measuring the cilinder bore, will a piston clearance of 0,07-0,08mm be ok? Is this ideal for aluminum cilinder-piston usage?

My cilinder is used, but come with an Asso (Polini like) piston. Can I assume my cilinder is nicasil coated?

Gruss,

Matt

Ps. Ain't Atom007 using a GS piston in his marvellous "little" Pinasco?

[Simmerl]

muss man hier englisch

der atom fährt in seinem 177er den wiseco kolben.

in meinem werkelt, wie der gravedigger schon verraten hat, der gs-kolben.

bin bisher (ca. 500km) sehr zufrieden damit. hab mich beim bearbeiten noch ein wenig zurückgehalten, aber da geht noch was.

seit gestern hängt nun der atom-v2 drunter, jetzt darfer dann auch richtig drehzahlen machen

This message was translated by Babelfish.

:grins:

[morbin]

muss man hier englisch

der atom fährt in seinem 177er den wiseco kolben.

in meinem werkelt, wie der gravedigger schon verraten hat, der gs-kolben.

bin bisher (ca. 500km) sehr zufrieden damit. hab mich beim bearbeiten noch ein wenig zurückgehalten, aber da geht noch was.

seit gestern hängt nun der atom-v2 drunter, jetzt darfer dann auch richtig drehzahlen machen

This message was translated by Babelfish.

:grins:

viel Dank

was ist lhr kolben spiel?

[atom007]

This message was translated by Babelfish.

:grins:

und das kommt dabei raus:

..der gs Kolben morgens (ca. 500km) sehr contently mit ihm ich mit, um auf ruhigem ein anderes wenig zu bearbeiten, das zurück gehalten wird, aber dort noch geht.. ist eher was fuer die morgenversuessung, oder?

[Simmerl]

Bearbeitet 20. Oktober 2006 von Simmerl