Cylinder PINASCO Zuera SS 135cc Vespa Smallframe

Vespa Cylinder Pinasco 135cc

We would like to present two new Pinasco Zuera cylinders for Vespa V50, PK, Primavera, etc.

There are some novelties in the largeframe sector, such as:

• Vespa engine casing and
• tubeless split rim

And Pinasco is also offering two new cylinders for 125cc smallframe models.

Both cylinders have been thoroughly tested, for instance on the very popular 24h of Zuera (Spain), which is why both cylinders have been named Zuera.

Reed valve direct intake and reed intake cylinders

The model with reed valve direct intake has the byname SRV 135, while the version with reed intake cylinder was named Zuera SS 135.

Today we will take a closer look at Pinasco SS135 .

Delivered with

• Cylinder and cylinder head
• Piston, incl. gudgeon pin, piston ring and locks
• Material to fasten cylinder head
• Gasket set for cylinder base
• Plug for cylinder cowling

Cylinder head

The cast cylinder head is rather massive. Your eyes first hit the processed bottom side. The combustion chamber in the centre of the ignition plug is about 1mm withdrawn. Following the sealing surface’s outer contour, the cylinder head is centred. A cylinder gasket is not planned. Because the cylinder head is screwed 8 times and the sealing surface is rather large, a reliable sealing should also be guaranteed without any additional sealing elements. Pinasco recommends a torque of 12Nm for cylinder studs and the additional M8x25 screws of the cylinder head.

Due to the central ignition plug, the original opening in the cylinder covering needs to be closed. Pinasco paid attention to this small detail and also supplies a fitting plug. You will need an ignition plug with long thread. You are using a NGK ignition plug? We recommend a B9ES. You want to use a Zuera 135SS and are an ambitious racer? We recommend a B10EG.

Piston

The forged piston is 169 g light. Pinasco equipped the piston with a 1mm rectangular piston ring and 1mm G-shaped locks.
The hint of a gas flow guide in the shape of a small, bevelled edge beneath the gudgeon pin is very cute.
Before it was modern to have an open contour at the sides, this little trick was often used for pistons with a long piston skirt.
The Zuera 135SS piston has an additional sliding coating, just like many modern cylinders.
Pinasco does not fool around with gudgeon pins. The thin walls of the bolt were meant to reduce its weight.

Cylinder

At first glance the design of the transfers in the cylinder highly resemble those of Polini Evolution. You will see the difference though, when taking a closer look. The angles of the entry surface are clearly different from one another.

The height of the outlet and transfers and an assumed deck height of 0mm lead to a sporty trigger delay angle of 125°/185°.

The openings of the transfers in the cylinder base are already open, which is a variation to other cylinders.
The cylinder base has a diameter of 61.33mm. Therefore enlarging the hole in the engine casing is not necessary.

Just like for almost all the other performance oriented cylinders, the open transfers in the cylinder base demand you to adapt the cooling port of the stator housing.

The one-piece outlet with a width of about 66% was made to endure. We would assume that the Zuera 135SS with its really sporty outlet design has a higher performance than Polini Evolution I.
The angle between the outlet and the transfers lead to the assumption that the Zuera 135SS also supports those exhausts with high revs.

Pinasco recommends a squish gap of 1.0 – 1.1mm. You may adjust it with 3 cylinder base gaskets, which are also supplied. When it comes to cylinder gaskets or sealing and links to the exhaust, Pinasco is reserved. No fitting exhaust gasket or outlet stud is delivered with the Zuera SS135.

You may well use material by Piaggio as a fitting outlet stud.

A combination of M8 outlet studs and the distance between them limits the variety of possible exhaust gaskets.
Sadly Pinasco does not supply fitting gaskets.
PK125 exhaust gasket by Piaggio fits the flange. However, the outlet of the SS135 measures 31 x 27mm, not making the PK125 exhaust gasket
with a smaller diameter the perfect fit.
The BGM exhaust gasket is an alternative, in which case you need to enlarge the bolt pitch in the gasket by a few millimetres.

Technical details of the Zuera SS135 cylinder

• Hole 57,5mm
• Stroke 51mm
• Cubic capacity 135cc
• 5 transfers
• One-piece outlet, trapezoidal, chord 38.5mm ? 66%
• Outlet stud M8 (not included, we recommend Piaggio)
• Bolt pitch exhaust flange 52mm (we recommend a BGM exhaust gasket)
• Three cylinder base gaskets 0.1mm each
• Cylinder base Ø=61.3mm (suitable for Piaggio)
• Forged piston 169g, one piston ring 1mm
• Piston pin retainer type G, 1mm
• Cylinder head, screwed 8 times (stud + 4 pieces M8x25mm)
• Ignition plug 14mm, long thread, recommendation B9ES, B10ES
• Position of ignition plug, central
• Ignition point 17° (recommended by Pinasco)
• Trigger delay angle 125°/185° with a gap dimension of 1.0mm and 51mm stroke

Conclusion new Pinasco Vespa cylinder smallframe

In total Pinasco has put together a sporty cylinder, which offers positive performance at little effort.

Be it in combination with SHB19, CP carburetors by Polini and Piaggio or Polini banana or in combination with a Keihin 28 and a Franz – in combination with a suitable carburetor and exhaust, Pinasco SS135 offers a performance range from moderate to sporty.