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VVT

Suzuki sedang membangunkan sistem VVT (variable valve timing/pemasaan injap boleh ubah) untuk enjin kecil.VVT dan pengangkat injap boleh ubah (VVL) bukanlah teknologi baharu kerana banyak pengeluar sudah menggunakannya dalam produk mereka, tetapi sistem Suzuki nampaknya untuk enjin 250cc. Ini memberi petanda baik kerana terdapat sama ada motosikal berkapasiti besar dan berkapasiti kecil menggunakannya tetapi tiada dalam segmen 250cc.

Sistem Suzuki pada asasnya serupa dengan VVA (Variable Valve Actuation) Yamaha yang digunakan pada skuter NVX, Y16ZR dan YZF-R15. Ia menggunakan aci sesondol dengan dua profil sesondol, satu untuk julat RPM rendah dan aplikasi pendikit yang kecil, serta satu lagi profil sesondol yang dikunci pada RPM yang lebih tinggi atau pembukaan pendikit yang besar.

Oleh itu, ia adalah yang terbaik untuk dua alam: Tork RPM rendah dan pertengahan yang baik dengan kuasa maksimum yang tinggi. Sebaliknya, jurutera terpaksa memilih satu ciri: Samada tork RPM rendah, atau tork julat pertengahan, atau kuasa maksimum yang tinggi.Pengunaan VVT juga membolehkan enjin menghasilkan pelepasan ekzos yang lebih bersih kerana ia mengurangkan bahan api yang tidak terbakar.

Seperti yang dinyatakan sebelum ini, pembangunan Suzuki tertumpu pada enjin 248cc berkembar selari. Aplikasi paten menunjukkan enjin dengan bahagina bawah yang sama, serta kepala silinder dengan aci sesondol tunggal didorong oleh rantai yang dipasang di tengah. Ia adalah enjin sama yang digunakan pada GSX-250R dan V-Strom 250.

Enjin ini yang diperbesarkan kepada 298cc turut digunakan oleh rakan kongsi Suzuki Haojue di China. Haojue ialah firma yang bertanggungjawab untuk mengeluarkan V-Strom 250 dan GSX-250R.

Buat masa ini, Suzuki tidak mempunyai sebarang model di antara banjaran model GSX-R125 dan 650cc (V-Strom 650, SV650) di Amerika Syarikat kerana kawalan pelepasan ekzos, jadi rangkaian motosikal 250cc dengan VVT membolehkan Suzuki memasukki semula pasaran tersebut.

Suzuki is developing a VVT (variable valve timing) system for a small engine.

VVT and variable valve lift (VVL) are not a new technologies as many manufacturers are already employing it in their products, but Suzuki’s system appears to be for a 250cc engine. This bodes well as there are either large capacity and small capacitiy motorcycles employing it but not the 250cc segment.

Suzuki’s system is basically similar to Yamaha’s VVA (Variable Valve Actuation) used on the NVX scooter, Y16ZR moped, and YZF-R15. It uses a camshaft with two cam lobe profiles, one for normal low end, low demand application, while locking on a higher lift and longer duration cam lobe at high speeds or big throttle openings.

As such, it is the best of both worlds: Good low and midrange RPM torque with high maximum power. Engineers have to pick one characteristic: low RPM torque, midrange torque, or high end horsepower without VVT and VVL. Using VVT also allows the engine to produce cleaner emissions as it cuts down on unburned fuel.

As aforementioned, Suzuki’s development centres around the parallel-twin 248cc engine. Patent applications show an engine with an unchanged bottom end, a cylinder head with a single camshaft driven by a centrally mounted chain. It is the same engine used on the GSX-250R and V-Strom 250.

The same engine, enlarged to 298cc is also in use by Suzuki’s partner Haojue in China. Haojue is the firm responsible for producing the V-Strom 250 and GSX-250R.

Suzuki current does not have any models in between GSX-R125 and 650cc models (V-Strom 650, SV650) in the United States due to emissions control, so a range of 250cc bikes with VVT will fix that.

In an era marked by the anticipation of the internal combustion engine’s demise, Italian manufacturer Piaggio is breaking new ground in engine development.

  • Despite the ongoing shift towards electric power, Piaggio is focusing on enhancing the efficiency of small, low-cost engines for scooters.
  • The company’s latest innovation is a Variable Valve Timing (VVT) system designed specifically for these engines.

Piaggio’s VVT system, outlined in a detailed patent application, aims to optimise the intake timing on single-cylinder, single-overhead-camshaft engines used in scooters. Given the tight profit margins in this segment of the market, the design emphasises simplicity and reduced component count.

At first glance, Piaggio’s SOHC VVT system appears similar to Yamaha’s “VVA” (Variable Valve Actuation) design used in various motorcycles. However, a subtle yet crucial difference sets Piaggio’s system apart.

Both systems employ two profiles for the intake cam lobes, which act on a forked rocker arm to control two intake valves. Like Yamaha’s VVA, Piaggio’s system uses a pin to connect or disconnect the rocker arm, with an actuator to engage it and a spring to disengage it when not needed.

The key distinction lies in the number of elements in the rocker arm. Yamaha’s VVA system features two parts: one conventional rocker and one element for high-lift, long-duration cam lobes. In contrast, Piaggio’s design incorporates three elements in its rocker arm, allowing for more comprehensive control over valve timing, lift, and duration.

This innovation enables the Piaggio system to adjust not only valve lift but also timing, offering a distinct advantage over Yamaha’s system, which can only switch between low-lift, short-duration and high-lift, long-duration lobes. With Piaggio’s design, the high-rpm cam lobe can have different timing, enhancing engine performance at high revs.

The patent showcases this system on an engine that resembles the Vespa GTS 300, utilised in various Piaggio models, including the Piaggio MP3. Piaggio’s commitment to improving small-engine efficiency reflects its dedication to innovation in an ever-evolving industry.

Dalam usaha memastikan legasi Hayabusa terus berjalan dalam era peraturan emisi yang semakin ketat, Suzuki telah pun memfailkan paten baharu yang merujuk kepada Suzuki Hayabusa akan dinaik taraf dengan sistem ‘variable valve timing’ (VVT). 

*Suzuki Hayabusa 2018

Penjualan Hayabusa telah pun dihentikan di beberapa pasaran dunia sekitar 2018 sebelum kilang Hamamatsu memperkenalkan generasi terbaru pada 2021 yang tampil dengan enjin lebih bersih dan reka bentuk berbeza. Bagaimanapun, dalam usaha mencapai standard emisi terkini, model 2021 itu datang dengan kuasa yang lebih rendah berbanding generasi sebelumnya. 

*Suzuki Hayabusa 2021

Enggan senario sama berulang, Suzuki telah memutuskan Hayabusa seterusnya akan dinaik taraf dengan sistem VVT yang bukan sahaja akan meningkatkan kuasa malah turut menawarkan penggunaan bahan api yang lebih jimat dan emisi yang lebih rendah. 

Difahamkan, sistem VVT yang akan diguna pakai Suzuki mirip dengan teknologi yang diterapkan masa kini pada motosikal dan kereta iaitu dengan melambatkan masa ‘intake cam’ pada kelajuan rendah sekaligus mengurangkan jumlah injap bertindih. 

Untuk rekod, injap bertindih bermanfaat bagi mengisi silinder dengan intake baharu pada RPM tinggi namun pada RPM rendah, senario itu menyebabkan campuran tidak terbakar memasuki ekzos lalu mencemarkan ‘catalytic converter’. Keadaan itu boleh memberi kesan pada kecekapan bahan api dan meningkatkan emisi. 

Penerapan sistem VVT baharu ini akan memastikan penjualan Hayabusa akan terus dibenarkan terutamanya di beberapa negara Eropah dan Amerika Syarikat yang dijangka akan memperkenalkan peraturan emisi lebih ketat dalam masa terdekat. 

Ketika ini, penjualan GSX-R1000, GSX-R750 dan GSX-R600 telah pun dilarang kerana gagal mencapai sasaran emisi Euro 5. 

Apa yang pasti sistem VVT pada Hayabusa bukan sahaja membolehkan model itu kekal relevan untuk pasaran dunia masa kini malah memastikan enjin empat silinder 1,340cc itu kekal menghasilkan output yang tinggi setaraf namanya. 

Aprilia is set to join the likes of Ducati, Yamaha, Kawasaki and Suzuki by introducing its own variable valve timing (VVT) system as confirmed by latest patent application submitted by parent company, Piaggio Group. 

The patent – based on the Aprilia RSV4 – showcased a non-electronic VVT system that works similar to Suzuki’s GSX-R1000 whereby the system depends on centrifugal force to move the ball bearings located on the drivel wheel of the intake camshaft. 

However, while the GSX-R1000 VVT works on 12 ball bearings, the upcoming RSV4 will used only three. 

Despite that, we expect the system to worked well similar to any VVT technology available on modern two-wheels.

That said, Aprilia is working on a mechanical-based VVT as compared to electronics, currently adopted by Ducati, Kawasaki and Yamaha. 

However, the new system could also be applied to other Piaggio-owned brand, including Moto Guzzi. 

  • Indian Motorcycle patented their variable valve timing (VVT) system.

  • It will equip a new Euro 5-compliant engine.

  • The technology is the best solution in delivering power with low fuel consumption and emission.

More and more manufacturers embrace variable valve timing technology as Euro 5 looms. Indian Motorcycle is next up.

As Euro 5 seeks to cut more emission, motorcycle manufacturers are forced into looking for other solutions. It was either that or downsizing the engine or reducing power production (god forbid!).

Right now, VVT offers the best answer. Variable valve timing and variable valve lift controls valve overlap at the correct engine loads and timing, yielding power while saving fuel and limiting emission at the same time. Please click the link below to learn more about variable valve timing/variable valve actuation.

2019 Ducati Diavel 1260 to Feature DVT

VVT usually finds place in motorcycles with “sportier” deposition such as the BMW S 1000 RR, Suzuki GSX-R1000, it’s made its way into other types of motorcycle engines. Ducati uses their proprietary Desmodromic Valve Timing (DVT) in the 1260cc V-Twins, while Yamaha employ the tech in their scooters. BMW has now equipped the new 1254cc Boxer (flat-twin) with their own “ShiftCam” technology.

Photo credit – United States Trademark and Patent Office, Motorcycle.com

A new Indian engine was spied months back, but patents revealed that the American manufacturer is pursing VVT technology as well.

Indian’s VVT looks different in because the engine employs overhead valves (OHV) and pushrods rather than overhead camshafts (OHC). Therefore, the VVT phaser is situated at the of the crankcase.

  • Suzuki tampak sedia untuk menggarapkan sistem pemasaan injap boleh ubah (VVT) baharu pada model GSX-R1000 baharu mereka.
  • Sistem semasa menggunakan daya emparan.
  • Sistem baharu ini mengikuti trend semasa menggunakan VVT yang diaktifkan secara hidraulik.

(more…)

  • Suzuki looks poised to install a new variable valve timing system in the new GSX-1000.

  • The current system uses centrifugal forces.

  • The new system follows the trend of using hydraulically-activated VVT.

The current Suzuki GSX-R1000 is already employing variable valve timing (VVT), but the new generation will feature a newer VVT.

As of now, the Suzuki GSX-R1000 VVT technology is derived directly from the Suzuki GSX-RR MotoGP bike. MotoGP regulations forbid hydraulic, electric and electronic variable valve timing and variable valve lift systems. Hence, Suzuki worked around this restriction by designing and employing a mechanical solution since 2015. The system works by using centrifugal force generated by the camshaft as it spins.

However, Suzuki has submitted the patents for a “traditional” hydraulically-activated system for the road bike. According to the documents, it is an oil pressure-activated, cam-shifting system.

Like the VVT patents of Honda, Suzuki’s VVT will activate both intake and exhausts cams. The current Gixxer is great to ride, but there are limitations of the current VVT due to the weight of the springs and gyroscopic forces in the mechanism.

It is also different from the BMW S 1000 RR’s ShiftCam system.

We foresee more motorcycles will be fitted with VVT systems of sorts in the years to come. As we mentioned before, VVT is one of the best ways to combat exhaust emissions and fuel consumption while still providing loads of power.

  • Honda telah memfailkan paten bagi teknologi ‘variable valve timing’ (VVT) baharu mereka.
  • Adakah teknologi ini bakal dilengkapkan pada model CBR1000RR Fireblade baharu mereka?
  • VVT menawarkan kuasa dan juga pematuhan kepada piawaian emisi.

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  • Honda filed for a patent for their new variable valve timing technology (VVT).

  • Could this be fitted to the new CBR1000RR Fireblade?

  • VVT offers both power and adherence to emissions standards.

Honda filed for a patent for a new variable valve timing (VVT) technology recently. Could it be for the new Honda CBR1000RR Fireblade most probably due in 2020? Or could it be fitted over other ranges of models, as well?

Honda’s new VVT system is akin to the BMW ShiftCam system which switches cams.

Each cylinder is fitted with two distinct cam lobes, one for low revs and another for higher revs. Like BMW’s system, the camshaft is slid back and forth to allow the appropriate cam to act on the finger followers, which in turn push open the valves. However, Honda’s system differs by having the system on the exhaust cam, as well.

This new system is different from Honda’s own iconic Variable Valve Timing & Lift Electronic Control (VTEC). It engages or disengages one set of cam lobes depending on engine load, whereas the new system’s cam lobes all spin at the same time.

Variable valve timing technology is not new in the world of motorcycles. As emission standards become tougher while the demand for more power grows at the same time, VVT is the only way to go. (Please click here to learn more about VVT and DVT.)

Almost all manufacturers employ VVT technology nowadays, although it is starting to be a trend among sportbikes. Heck, even the Yamaha N-Max, NVX and X-Max scooters feature VVT.

But it was Honda who first introduced VTEC to the in the 1989 Integra. It took another decade before it was adopted by the Honda CB400 Super Four VTEC in 1999. Since then, the Ducati Multistrada 1200 and its successor the Multistrada 1260, Kawasaki 1400GTR, Suzuki GSX-R1000 employ one form of VVT or another.

Ducati-testastretta-DVT-Desmodriomic-valve-timing-14

New Ducati Testastretta DVT engine technology revealed, 2015 Multistrada will adopt it first.

(more…)

ducati-superquadro-motor-5

Ducati set to introduce new engine with ‘DVT’ variable valve timing (VVT) technology this month.

(more…)

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