Skip to main content

The New Waissi Engine, Pistons But No Connecting Rods

Waissi’s latest design, which will be the basis for the prototype that hopefully runs. Stiffer solid plates have replaced the steel rods that keep the pistons attached to each other and properly phased.
Waissi’s new engine is an opposed piston configuration that uses conventional head, valve and combustion chamber designs. What’s different is that the Waissi engine has no connecting rods between the pistons and the crankshaft. Instead, the pistons push directly on what Waissi calls a “crankdisk”. The engine’s output shaft has a large journal mounted eccentrically on the shaft, with a bearing ring that spins on the journal. The outside surface of the bearing ring fits into a landed grove at the bottom of the piston structure. When the piston is pushed down during the power stroke,  the downward motion of the piston causes the crank to spin because of the offset as the bearing ring rolls under the piston landing. Each piston has an opposed twin which then spins the crank disk another 180 degrees to complete a revolution. The two pistons are attached to each other via steel rods, which keeps them timed properly. In his latest design, Waissi has replaced the rods with solid plates.

The advantage over a conventional connecting rod engine is reduced friction, reduced weight, and reduced complexity. For a four cylinder engine, Waissi’s piston/crank assembly has only five moving parts vs nine for a standard engine. Fewer parts means lower cost.Many of today’s new engine designs are focused on reducing friction. 
The Waissi engine has nine bearing surfaces compared to 11 for a standard motor. Four of those nine surfaces, where the pistons meet the crankdisk bearing ring, are rolling surfaces which have significantly lower friction than the sliding surfaces in a conventional engine’s piston rod big end bearings. Because the two pistons are fixed to each other there is also reduced friction from pistons rocking and then scraping the cylinder walls. Waissi calculates that total friction will be 50% of that of a conventional engine.
The “crankdisc” that is at the heart of the Waissi engine design
Dynamic balancing is also simpler because there are no rocking connecting rods generating secondary forces. Waissi claims that because there are no connecting rods, the piston acceleration and force curves follow an ideal, perfectly sinusoidal path, something that would only be possible in a conventional engine if the connecting rods were infinitely long. That should result in a smoother running engine.The concept is not fuel or cycle dependent so two-strokes and diesels are possible. Other than how energy is transferred from the pistons to the output shaft, everything else works the same. 
The concept is based on a two cylinder module, so 4, 6, and 8 cylinder (or more) versions are possible by just stacking modules with the correct phasing to maintain dynamic balance. The four cylinder’s two modules would be phased 180° apart, a six cylinder would have them 120° apart and an eight would have the modules phased 90°. As with Ecomotor’s similarly modular OPOC engine, or with Chrysler’s aborted Gemini engine developed by Roush, cylinder deactivation could  be effected by a clutch between the modules, allowing a module to be completely shut down, unlike in a conventional multi-displacement engine which still has frictional and pumping energy losses from the deactivated cylinders.
The crankdisc actually rolls under the pistons. Rolling friction is reduced compared to the spinning friction of a conventional con rod’s big end bearing.


Popular posts from this blog

7 Mistakes To Avoid When Driving A Car With Automatic Transmission

Individuals associated with the automotive industry iterate that the automatic transmission is a great invention. Actually, an automatic car has opened up a whole new world for car owners.
Both professional and novice drivers love to drive a car fitted with automatic transmission. This is because it is straightforward and easy to drive an automatic vehicle than a car fitted with the manual-shift gearbox. Think about the bumper-to-bumper story we have in the cities! However, it is very important to drive a car with automatic transmission carefully because you could end up damaging your car. Some damages, if they happen, cannot be rectified even by expert mechanics. Therefore, it is best that you avoid the following mistakes when driving your automatic vehicle.  

Credits: Team BHP
#1: Coasting downhill in neutral
You would save a little bit of fuel when you coast down a hill in neutral gear. However, it is very negligible. In modern automatic transmissions, fuel supply to the engine is auto…

The Most awaited Yamaha YZF-R15 Version 3.0

Yamaha has officially unveiled the R15 Version 3.0 in Indonesia. The all-new 2017 R15 is powered by a 155.1cc engine, which develops maximum power of 19.04 Bhp @ 10000 rpm and maximum torque of 14.7 NM @ 8500 rpm. The engine is mated to a 6-speed gearbox, and the key rivals of R15 V3.0 are 2017 Honda CBR150R and Suzuki GSX-R150. As of now, Yamaha has not announced anything officially regarding the launch of R15 V3 in India, it is expected to be here within next 3-4 months .

Yamaha YZF-R15 Version 3.0 is expected to be launched in 2017 but as of now there are no official launch dates. So, we will have to wait a bit more before the official statement comes in. It is expected to be priced between Rs. 1.30-Rs. 1.35 lakhs (ex-showroom). It is expected to share its design elements from M-Slaz, Yamaha YZF R125 and YZF R6.

ENGINE, POWER & TORQUEDisplacement155.1 ccMaximum Power19.04 Bhp @ 10000 rpmMaximum Torque14.7 NM @ 8500 rpmEngine DescriptionLiquid-cooled, 4-stroke, SOHC, 4-valveCoolin…

5 Cars You Should Be Really Excited to Buy as your first car

1. Maruti Swift The next generation Swift was revealed recently and is expected to come to India soon. Based on the Baleno chassis, this third-generation Swift is shorter than the current one, but has a longer wheelbase – that means there’s probably more room inside. Given the strong brand value, it will probably sell well. This cars seems to be the most perfect and desired  car of 2017, with attracting the modifications and different sheds of colours launched in market.
Price: Rs 5 lakh onward
2. Maruti Ignis  :

The hatchback that has SUV intentions will be among the first car launches of 2017. The Ignis has a tall stance like an SUV, but a small footprint like a hatchback. To be sold by Maruti’s premium Nexa dealerships, it will be powered by the same 1.2-litre petrol and 1.3-litre diesels as the Baleno. It is good car to buy as your first car , the complete and perfect for family and under your budget at just Rs 5.0 Lakhs,  

3. Tata Nexon
If you’ve been waiting to buy a new car, hol…