L? Wensenf Vespa with 40,7 hp

Vespa Falc Racing lion mustard

The Classic Scooter Facebook Customshow is currently running on ours Facebook-Seite.

In the course of the customshow we want to show you here, in the Scooter Center Magazine regularly introduce classic Vespa and Lambretta scooters that take part in the show:

Today: Vespa Falc Racing Löwensenf

The information from the owner is briefly meaningful:

Falc engine with 40,7 hp

Vespa Falc Racing Löwensenf 40,7 HP

This is the Vespa Falc Racing Löwensenf (Smallframe Vespa)
You can get Falc Vespa Racing products cheaply at Scooter Center Vespa Shop: Falcon Racing

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For example this cylinder -Vespa FALC RACING 153 cc (54mm stroke) - Vespa V50, PV125, ET3, PK50, PK80, PK125

Racing cylinder very first cabin!

Here you can find the Vespa Falc Racing 153 cc Nikasil coated aluminum cylinder with 60mm bore and for 54mm long stroke shafts. Membrane direct inlet, 5 transfer ports, split outlet channel are a clear message.

The huge diaphragm direct inlet supplies the cylinder with fresh gases via a 6 flap membrane. Supported by additional Boysen ports. The lavishly dimensioned intake manifold is included in the scope of delivery, as is the flow-optimized stuffer. Even if it is designed for the V50 / PV / ET3 models, the frame must be adapted to the huge intake pipe diameter. (Also necessary when used on the PK.)

In order to be able to distribute the quantities of fresh gas, the overflow areas are designed accordingly generously. The four windows in the cylinder liner ensure a very clean flushing pattern. The housing does not necessarily have to be welded on, which is of course not a problem in order to achieve optimal performance.
BR> In order to create space for the fresh gases, the old gas is disposed of accordingly thanks to sufficient duct space and control time. In order to be as free as possible in the outlet design, the spacing of the stud bolts at the outlet has been increased to 60 mm. The outlet bar was necessary to guide the rings.

The cylinder head is optimized for better air circulation and is centered via a shoulder.

High end tuning with the performance of 30 HP and more are feasible!

Vespa racing engine with 35HP + part 2

Today the first part of the innards of the Vespa racing engine is on.

Special requirements call for special solutions.

The crankshaft is subject to very high loads. It has to transmit the pressure generated by the combustion in the cylinder to the drive in a translatory manner and is subject to rapid jumps in engine speed during racing. Our special shaft weighs almost 2000 grams. and is therefore a lot more massive than an already quite officially balanced Polini rotary valve crankshaft with 1400gr.
In direct comparison, a V50 crankshaft weighs just 900 grams. a real flyweight.

The high mass of the crankshaft allows the engine to run very smoothly and is less likely to be disturbed by a rather heavy piston.

However, the rotating heavyweight requires proper storage, after all, with increasing speed, the loads and forces acting on the bearings increase exponentially.

quattrini falc03 (1)

The inner ring of the bearing is used for lateral guidance in the housing. Therefore, the axial play in the housing must be measured in advance for installation.

With a depth gauge, measuring is very easy and accurate. For self-control, we carry out several measurements at different positions in order to avoid a measurement error.

quattrini falc 004

The dimensions of both housing halves add up to an installation width of 78,05mm. We do not need to consider the strength of a housing seal. As is customary with modern assemblies, the Quattrini housing is made without a solid seal and only with Sealant put together.

In order to know before installing the bearing with which thickness of shim rings we need to insert the bearings in the housing, we need the installation dimension of the crankshaft.

The inner rings are shrunk onto the stub shaft. To be on the safe side, if an inner ring should jam during assembly, we fix the crank webs with one more to the crank pin Directional wedge and put one Recoil-free plastic hammer ready.

quattrini falc2 015

The crankshaft is with Cooler spray cooled down ...

quattrini falc2 017

and which heats the inner rings in the assembly tool.

quattrini falc2 019

As expected, the heated inner rings fell onto the crankshaft stubs without any problems and we can measure the installation width of the shaft.

quattrini falc2 021

The micrometer gives us a dimension of 77,58mm. With a desired installation clearance of 0,20mm - 0,40mm, we need a shim of 0,20mm. With that we end up in the middle of the tolerance field.
In our case we only need to compensate 0,20mm. If the dimension is larger, it is advisable to compensate for the axial play on both sides, as otherwise one-sided pressure load can occur on the connecting rod and connecting rod bearing. In the performance and speed category we strive for, the cornerstone for a reasonable defect ...

All other bearings are also used by shrinking.

At the primary bearing, the 16005 , we consciously choose a bearing with increased internal clearance “C3”.
The bearing fit in the Quattrini housing is in the lower tolerance range, so it is rather tight.
After shrinking, the housing moves back in and increases the pressure on the bearing outer ring. By installing the primary, the inner ring of the bearing is also expanded, which further reduces the bearing clearance. If the bearing clearance is too small, the bearing would run too tight and thus be damaged in a relatively short time.

At the camp for the Main shaft on the wheel side, we use a 6204RSH, i.e. with a one-sided seal.

This means that the brake anchor plate can be removed without losing oil when changing the primary or working on the clutch.

Before the auxiliary shaft and auxiliary shaft bearings go into the engine, we check the installation clearance of the crankshaft.

The simplest method is to control via Feeler gauge.

falc quattrini3 002

The crankshaft is simply inserted into the housing and the housing is screwed into the stator housing. Then the shaft is pulled once to the stop on the gear side and measured between the cheek and the flat surface in the housing. The crankshaft is then pulled to the alternator side and the gap is measured again. The resulting difference in dimensions is therefore our installation clearance. In our case the values ​​are 0.70mm and 0,50mm, so the installation clearance is in a healthy range of 0,20mm.

Next we check the seat of the clutch spider on the auxiliary shaft. The cons must fit perfectly so that the force can also be transmitted on this tiny surface.

Copy of falc quattrini4 014

The contact pattern can be determined very well with valve grinding paste. When the cone is flat, the auxiliary shaft is ready for installation.

The spurious and the 6200 we use it together because the installation position is deep in the housing and the small bearing is difficult to handle when loose.

falc quattrini3 006

Once the auxiliary shaft has taken place, we can start measuring the clutch.

Vespa racing engine with 35HP +

The racing season is approaching with giant strides. Only a few weeks until the first ESC race begin.

You can find information about all classes and the ESC racing series at

Our Vespa racing engine is used in class 2, the premier class of the Euro Scooter Challenge.
In this class there is practically only a displacement limitation of <150ccm as a regulation.
The top units in this class produce between 35HP and 38HP

Therefore, in most cases you will find a stroke / bore combination of 53/60, which results in 149,85ccm.

In our case, too, we pay for our Vespa engine Falc cylinder with 60 mm bore and a special crankshaft with 53mm stroke, suitable for the Quattrini motor housing, for use.

So that you can get an overview of which parts can be used in such an engine, we first laid everything out nicely ...

Vespa racing engine Smallframe Quattrini FALC all parts for the Vespa tuning project racing engine 35HP +


... and wrote you a shopping list on which you can find all the items you usually need.
This CSV file you can simply upload it to our online shop and then take a close look at all the items in your shopping cart.

We are only now taking a closer look at the motor housing. In the performance range we strive for, even small mistakes can have devastating effects. Therefore, each individual part should be carefully checked before assembly. Especially when partially used parts are used, as in our case, because proven ones can of course be used again as long as the parts are in good condition.

In the case of the motor housing, we first check all sealing surfaces and bearing seats.
In the area of ​​action the spurious if a franking is noticed ...

Vespa racing engine gearbox Smallframe Quattrini FALC

Here it would be included in the later installation Warehouse get into trouble. Later on, on the racetrack, this can lead to further problems if a different gear ratio should be necessary due to the route profile.

So we have to rework the undercut so that the auxiliary shaft can simply be pulled out of the bearing and against a longer translated version lets swap.

Motor housing Vespa racing engine Smallframe Quattrini FALC

Furthermore, there are no more special features in the transmission.

The “small” half of the case, however, still has a problem.
Normally you simply screw the stator the ignition tight, fumble the cables and ... uh ..

Ignition Vespa racing engine Smallframe Quattrini FALC

you definitely don't get one here Cable branch of the stator out of the danger area of ​​the rotor.
Since we unfortunately cannot provide a WiFi ignition in the short time, a suitable outlet must be created.
It is important that you do not drill randomly anywhere into the housing and create additional, unsuitable ventilation holes.
You should also make sure that the cable branch is still held down by the stator plate in order to avoid really abrasive contact with the rotor.

For the sake of simplicity, we use one as protection in the implementation Rubber grommet of the V50.
The appropriate hole for this is 12,5mm.

Holes over a diameter of 10mm should always be pre-drilled smaller.

Drilling Vespa racing engine Smallframe Quattrini FALC

... and then bring it to the desired level.

Engine casing drill Vespa racing engine Smallframe Quattrini FALC

Deburr the hole and try it on briefly.

Test Vespa racing engine Smallframe Quattrini FALC

All fine. The small half of the case is done with the rough adjustments.

Next, the area of ​​the cylinder base comes into the focus of our assessment.

The Falc cylinders are manufactured with a cylinder base diameter of 66,5mm. Of course, Mr. Quattrini designed his motor housing for a diameter of 65,2mm, just to match his cylinders.

Measure Vespa racing engine Smallframe Quattrini FALC
This results in two possible options:

1. The motor housing can be spindled to the appropriate cylinder base diameter

2. The cylinder base of the Falcen is given a new outer diameter

We choose option number two.

So if you wanted to go back to one at some point other cylinder turn around, all options remain open. The wall thickness of the cylinder base is completely sufficient for this step.

Turned off briefly, the cylinder can be held in the housing for a test to determine the extent to which the processing of the overflow channels still requires.

Cylinder duct vespa racing engine Smallframe Quattrini FALC

Almost perfect, we only have to rework the outer edges of the channel in the cylinder. The case remains untouched at this point. We make the necessary changes after determining the control angle on the cylinder.

The motor housing is delivered without silent rubbers. There are some more or less sensible solutions for the traverse available on the market. Personal preferences also play a role in racing. The rubbers shouldn't be too hard. “Blocks” with more than 70 Shore hardness are certainly justifiable for fast straight-ahead driving, but as soon as you start doing gymnastics exercises on the scooter to quickly circle the bullet around the curves on a kart track, the requirements are more like the rest of the chassis: “as hard as necessary, as soft as possible ”.

Therefore, in our case, we use the Silent rubbers of the V50 / Primavera Models with approx. 50 Shore hardness.

Silent rubbers motor housing cross member Vespa racing engine Smallframe Quattrini FALC

On closer inspection of the traverse holes, it is noticeable that the stops for the silent rubbers turn out to be rather small. In order to avoid that the rubbers slowly walk into the bore with the high lateral forces and the housing can begin to move sideways, we use the additional stops from the PK models.

Here is the small stop surface ...

Stop traverse Vespa racing engine Smallframe Quattrini FALC

The stop ring of the PK is simply inserted and afterwards, when installed, is fixed by the silent rubbers.

Traverse Vespa racing engine Smallframe Quattrini FALC

The soft truss rubbers can be moved relatively easily with talc or a little Montagepaste used.

“He who is lazy is also clever”; therefore we leave the slightly strenuous work to the workshop press. In an emergency, the two-part silent rubbers can also be easily replaced by hand.

Pressing in silent rubbers Vespa racing engine Smallframe Quattrini FALC

For the rear mount for the shock absorber, we use our own silent rubbers with the original case.

Compared to the Piaggio rubbers are our silent rubbers laid out a little wider ...

Comparison of silent rubbers Piaggio vs. Tuning Vespa racing engine Smallframe Quattrini FALC

and in the assembled state they are flush with the shock absorber eye on both sides. This gives you better lateral support.

Silent rubbers finished Vespa racing engine Smallframe Quattrini FALC

The next post is about installing the ball bearings and calibrating the crankshaft ...

Polini has a nice update for Smallframe Scooters at the start, of course in the SCOOTER CENTER Vespa shop will be available.

Started with
- a revised version (Racing) and
-Rotary slide aluminum version (Changes) of the 133cc cylinder,
- via IDM and digital complete ignitions,
- 2 new crankshafts (1x rotary valve with racing timing and a full cheek shaft)
- an Evolution 2 exhaust,
- 2 new intake sockets with 34 mm connection width for 2 and 3 hole housings, up to
- a totally new Polini cylinder. Whether there is competition for falc and Parmakit W Force gives!

Here is the news directly from the Polini website: