The perfect Vespa touring engine

Created by Jesco at 17:12 on December 13, 2021

Which touring engine is perfect for a Vespa? This is a question we at SIP Scootershop get asked again and again. Timo from the "Blechgefährten" has also been on the subject for a very long time, as he is looking for the perfect setup for his PX conversion. A setup that is suitable for everyday use as well as for long tours and mountain passes. Jesco didn't miss the opportunity to invite the YouTuber from faraway Wolfenbüttel (Jesco's hometown) to visit us at the Flagship Store in Landsberg to put together the numerous parts and details for a perfect touring setup together.

Cylinder QUATTRINI - Vespa Touring Engine | QUATTRINI M-244 Setup

Vespa fan Timo had already been working on his PX conversion project for over a year, but now it was time for the engine tuning. The basis: A QUATTRINI M-244 - probably the best all-round cylinder currently available for a Vespa PX 200 engine. It convinces both with its suitability for everyday use in city traffic and on further tours with its reliability, smooth running and, as a racing engine, with its torque strength and rich power. The QUATTRINI M-244 cylinder for 57 mm or 60 mm stroke has, as the name suggests, a cylinder with 244 cc displacement and is suitable for all large 200cc engines such as the Vespa PX 200, Vespa Rally 200 and Vespa Cosa 200 with Ducati ignition.

The Quattrini cylinder has the following special features: Firstly, it does not have a cylinder base that protrudes into the engine housing. The absence of the cylinder base means that a significantly larger piston with a very low compression height can be used. The compression height is the distance between the piston crown and the axis of the piston pin. In addition, the Quattrini cylinder requires a crankshaft with a very long connecting rod. Because the compression height is very low and at the same time the connecting rod is very long, a reliable cylinder with low piston tilt was feasible without a foot. This way, the overcurrent is so high that no adjustment in the engine housing is necessary - although an adjustment with files and milling is always advisable.

In addition, the cylinder has a 72 mm bore due to the lack of a foot. This means that the aluminium racing cylinder with Nikasil coating can be ridden virtually "plug & play". This was another criterion for Timo, who was keen on effortless implementation and assembly. So simply "look for the right components, plug them in - and then the thing runs", says the Wolfenbüttler.

By the way: Since 2020, the new versions of the Quattrini M-244 cylinders have a small bore above the exhaust port, also called a "decompression bore". This is intended to make the engine easier to "kick-start" - i.e. to start - and to run more smoothly at idle speed, especially in large-volume single-cylinder engines. The bore no longer has any influence on engine running and power development at higher speeds from around 1,500 to 1,800 rpm, as the cross-section of the hole is too small to allow a significant throttle change in a short time.

Another interesting detail of the Quattrini M-244 cylinder is that due to the lack of a base, the cylinder centres itself on the case by means of studs, which is why they are positioned relatively narrowly. In rare cases, there are certain engine cases where, given the tolerances, one of the stud holes needs to be widened. This compensates for the tolerance of the housing, while the other studs centre the cylinder. Although ordinary stud bolts can be used for this purpose, it is advisable to use stud bolts from the automatic range that are fitted with so-called expansion bolts. This is to counteract the deformation of the cylinder that can occur when heated.

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Crankshaft/Long stroke shaft - Vespa Touring Engine | QUATTRINI M-244 Setup

The crankshaft and cylinder are the heart of every engine, but also one of the most stressed. Vespa expert Jesco has therefore selected a 60 mm crankshaft for the YouTuber from the Blechgefährten, which fits perfectly to his setup and "plug & play" into the original housing, is particularly smooth-running and features high-quality materials and first-class workmanship. Another advantage is that all PX clutches can be run with the crankshaft as standard. In addition, there is now also an increased displacement from 232 cc to 244 cc.

A small tip: It is advisable to decide in advance whether the crankshaft should have an ordinary rotary vane intake or rather be converted to a diaphragm intake. In order to be as quiet and reliable as possible in everyday use, expert Jesco has recommended a rotary vane intake in this case.

SIP also has something brand new in its range: the SIP PERFORMANCE crankshaft/long-stroke shaft with splines on the clutch side, which normally has a cylindrical stub with a key. This gearing system, originally from the BFA engines, has now been adapted to the SIP PERFORMANCE long-stroke shaft and developed for different clutch systems.

Clutch - Vespa Touring Engine | QUATTRINI M-244 Setup

The perfect connection to the crankshaft is provided by the SIP COSA 2 Ultrastrong clutch. This is now also optionally available with the gearing from the BFA engines.

Small tip: For all those who prefer a crankshaft with splines instead of a whole new clutch, the clutch base plate MMW for clutch basket "Superstrong" "COSA 2" can of course be ordered separately. This makes it easy to change to the gearing system.

Kurbelwelle

Oil seal / shaft seal for sealing the crankshaft - Vespa Touring Engine | QUATTRINI M-244 Setup

The inner shaft seal is often considered the weak point of Vespa largeframe models with far-reaching consequences. In case of a defect of the inner seal ring, the whole engine has to be disassembled. In the past, solid rubber rings were available in brown, black and blue. These were followed by metal rings with only one rubber in the middle. Over the years, manufacturers such as Rolf with their "brown Rolf" and Corteco established themselves for sealing the crankshaft.

Fortunately, the high-quality sealing rings crankshaft seal KULU MALOSSI FKM 31x62x5,8 mm and the crankshaft seal KULU PIAGGIO 31x62x4,3x5,8 mm provide a remedy. Both offer a secure crankshaft seal for all Vespa largeframe engines, a snug fit and, when correctly adjusted, promise many years and kilometres of riding pleasure.

Carburettor and carburettor pan cover with separate lubrication - Vespa Touring Engine | QUATTRINI M-244 Setup

For an everyday touring as well as mountain-friendly setup, it is recommended to stay with the SI carburettor. Expert Jesco has chosen the PINASCO SI 26.26 VRX-R carb urettor for Timo from the Blechgefährten. This has a CNC-manufactured intake funnel and an optimised float needle valve with an enlarged flow bore. This should make the typical SI fuel supply problems with tuned engines a thing of the past.

Another plus point is the included accessories such as intake funnels and foam air filters, which do not have to be purchased separately. Small drawback of the funnel: The disadvantage of the design is the somewhat more difficult tuning of the carburettor or simply "give the carburettor a little more love when tuning it ", as Vespa expert Jesco calls it. However, the carburettor can also be installed without the funnel. This costs a little power, but is quieter and a little easier to tune.

But even the best carburettor cannot deliver its full performance if it does not have the possibility to suck in enough air. This is why the carburettor pan covers from PINASCO were developed. Thanks to their significantly larger volume, the engine can suck in air a little more easily. With this setup, this results in about one hp more power, which is available over the entire power band.

A practical gimmick is the rubber pin that is included in the scope of delivery. It provides additional safety, as it prevents the idle throttle screw from loosening and falling into the carburettor, which would destroy the rotary slide.

Ignition SIP PERFORMANCE by VAPE Road - Vespa Touring Engine | QUATTRINI M-244 Setup

One of the most successful products from SIP is the ignition SIP PERFORMANCE by VAPE. It provides a powerful power supply, a strong, reliable ignition spark and has a particularly stable pole wheel.

Many tuning ignitions have the problem that the current output is lower. "If you then stand at the traffic lights or at the level crossing at night, the light always goes dark and just glows away," says Vespa expert Jesco. This is not the case with the SIP PERFORMANCE by VAPE Road ignition, which is available in DC and AC versions. Here, eight light coils on the base plate generate sufficient electrical power even at idling speed. At higher speeds, this increases up to 110 W. Furthermore, the connection of additional digital elements or connection of LED lighting (with additional battery) is possible thanks to the integrated rectifier.

The SIP PERFORMANCE by VAPE ignition is available in two versions: as a road version with static ignition timing or flat ignition curve like the original and in the sport version with variable ignition timing and similar ignition curve to the IDM ignitions of other manufacturers such as Vespatronic, Malossi and Polini.

The extremely stable pole wheel, which is made from one piece, also has some advantages. Usually, the cone is connected to a pole wheel via rivets, but these form a weak point. Since the pole wheel is made from one piece and CNC, engine vibrations as well as wear and tear are minimised.

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Racing exhaust SIP ROAD 3.0 - Vespa Touring Engine | QUATTRINI M-244 Setup

The latest exhaust system from SIP is the SIP ROAD 3.0 racing exhaust, which offers several advantages. One of these is the dimensions, which correspond exactly to the original and thus come along inconspicuously in typical compact size and appearance. In addition, it provides full lean clearance, fits with all stands and can also be mounted on oldies like a Vespa Sprint or a Vespa VBB. In other words, a small box that can be combined well with a wide variety of "plug & play" setups with original carburettors and ridden comfortably - even with a Quattrini or Pinasco racing cylinder as well as an SI carburettor. Thus ideal for the city and the everyday cruiser.

Of course, the performance is also particularly noteworthy. "There are even more powerful box exhausts, but they are bigger, louder and more rev-heavy. And then there is this segment of box exhaust systems that are more suitable for everyday use. And in this segment, the SIP Road 3.0, together with Polini and Malossi, is one of the most powerful exhaust systems. However, the Racing exhaust SIP ROAD 3.0 only one that is based on an original box and combines torque with power and a pleasant volume", says SIP Vespa expert Jesco. Thus, thanks to the power increase, which is largely generated by the shape of the manifold, two to four hp more can be expected than with an original exhaust.

Racing exhaust POLINI or racing exhaust SIP ROAD 3.0?

Timo from Blechgefährten also asked this very question in the video. According to Vespa expert Jesco: "Depending on the setup, it varies a bit which one is stronger. There is very little difference between them". Although the Polini racing exhaust may be equally powerful, the SIP product can deliver the same performance with the same volume as the original. Another advantage is that it can be fitted to older models such as a Vespa Sprint, as the manifolds have also been designed to fit this.

Small tip: A test on the different box exhaust systems can be found here.

The gearbox of the Vespa Touring engine | QUATTRINI M-244 Setup

The primary gear ratio, which is part of the gearbox, determines the length of all gears. If you want to install a high-torque engine - such as a Quattrini with 62 mm stroke - it is worthwhile to extend the gear ratio.

In addition to the auxiliary shaft gear set Z 12-13-17-21 "Standard" DRT 804 for SIP with the original gradation, there are also gear sets with a narrower gradation, e.g. the auxiliary shaft gear set Z 12-13-17-20 BENELLI, where the fourth gear is one tooth shorter. Gear sets are also available in which the third and fourth gear - or even the fourth gear - is two teeth shorter - this results in better gear connections, but also in a considerably narrower gear spread.

In short, the installation of these gears allows the transmission to be further tuned to the needs of the rider and the intended use of the engine. Thus, depending on the engine power and desire, the ideal compromise between starting behaviour or gear ratio and top speed must be achieved.

It is important to note that especially with tuned engines, the jerk damping comes to its limits. This can mean that shocks are not sufficiently absorbed and that the springs break as a result. Gearbox damage is very likely to be the result. Therefore, it is advisable to use springs in the rear dampers that offer more resistance.

Small tip: In the meantime, there are also countershafts that can be screwed on. This is super-practical, easy to install and includes high-quality rear dampers.

The positioning of the gearshift cross on the drive shaft is considered a weak point on Vespa largeframe engines, along with the not quite optimal locking. The remedy here is a MOTORINO DIAVOLO sequential gearshift detent or the CRIMAZ drive shaft with integrated detent. This guarantees a better positioning of the gearshift cross in the gears and thus better prevents possible consequential damage such as gearbox impairments or a cracked engine housing.

Attention should also be paid to the quality of the gearshift cross. This is used for every gear change and is therefore one of the parts with the greatest load in a Vespa engine. Therefore, it should have the right hardness. It must not be too hard so that it does not destroy the flanks of the gear wheels. On the other hand, it should not be too soft either, so that it does not wear out too quickly. Since the quality of the PIAGGIO gearshift crosses now varies, we recommend the SIP BFA gearshift cross, for example. It was developed by the Italian high-tech forge BFA for SIP and has achieved excellent results in tests.

Would you like to see everything in picture and sound with further detailed and interesting information? Then just have a look at the accompanying video. Jesco and Timo discuss all the relevant components of the engine setup, from the cylinder to the oil seal and gearbox to the exhaust.

By the way: For the subscriber special, we shot a video with Timo with a look behind the scenes at SIP. So if you've always wanted to know what it's like here at SIP and how and where our hard-working employees work, you can find it at Timo's Tin Companions channel.

Here is an overview of all the product recommendations:

Jesco
Jesco

Jesco is a technician and product developer at SIP Scootershop. Many people know him from videos on the SIP TV Tutorial Channel, where Jesco explains complicated stuff in a simple way.