The Wankel (Rotary) Engine

The workings of a Wankel Engine

The Wankel engine (also known as the Rotary Engine) was invented by Felix Wankel, a German mechanical engineer in the early 1950's and underwent development during the 50's. A complete running prototype was ready in 1957 and it was then sold on to other companies who added their own improvements.
It is an internal combustion engine and does run on Otto cycle, BUT has no pistons.

It is a very compact and lightweight engine compared to its counterparts and as such has been very popular in a variety of vehicles since. Vehicles with wankel engines include automobiles, racing cars, water craft, go karts and have been put into devices such as chainsaws. It has been widely used in car making by Mazda, which fitted the rotary (Wankel) engine to many of its cars, including the Mazda RX8 (below)


The Wankel Powered Mazda RX-8

The wankel engine is generally more poweful than a conventional four stroke because in one revolution of the triangular rotor, there is one ignition (watch point a on the apex of the triangle on the animation above!) this means one power stroke in one turn of the drive, as oposed to one for every two turns of the drive shaft in a conventional engine.

Minimizing the space around the rotor is key to increasing pressure in the engine, making its output more powerful.

Advantages:

• Much smaller than a conventional 4 stroke, meaning it can be used in a wider range of applications.
• A better power output due to the one ignition - one rotation system.
• Very few moving parts compared to an ordinary engine, making it less suseptable to breaking down or suffering from wear.
• Very fast reaction to throttle changes
  
• They do not die, if a wankel engine goes wrong it will maintain and ever lowering power output as opposed to instantly dieing, maybe life-saving in aircraft

Disadvantage:

• More complex engineering involved and lots of seals needed (between rotor tips as well as against the chamber ends)
• The constant moving and heating in the engine can effect the seals and reduce efficiency
• As the stroke duration is half of the standard 4 stroke, the fuel has half the time to enter the chamber in the right place to be ignited, due to the way the three chambers rotate. The fuel-air mixture cannot be pre-stored as there is no intake valve.
• The surface/volume-ratio problem is so complex that you cannot make a direct comparison between a reciprocating piston engine and a Wankel engine in relation to the surface/volume-ratio. The flow velocity and the heat losses behave differently and surface temperatures behave absolutely differently. Engines with higher compression ratio have a worse surface/volume-ratio.

»»  read more

New Gulf Livery Aston Martin - Ready for Le Mans

New Gulf Livery Aston Martin for the 24hr Le Mans race

Probably the most oustanding colours in motorsport were unveiled today as Aston Martin Racings new Prodrive manufactured car was unvieled today to take part in the infamous 24 hour Le Mans race this June!

The full story from the BBC website is below:

Aston Martin Racing has announced it will take part in this year's Le Mans 24 Hours race in June.

It is 50 years since the British-based manufacturer won the top prize at the famous French race.

This year's car is being designed and built by Aston Martin Racing at the Prodrive factory in Banbury.

The team has won the GT class at Le Mans for the past two years but this year will challenge Audi's recent domination of the main race instead.

David Richards, chairman of both Aston Martin and Prodrive, said: "Le Mans 24 Hours is without doubt the greatest motor race in the world.

"It's been 50 years since we last won Le Mans outright and what better opportunity or way of celebrating that anniversary than having another go."

The announcement comes despite Aston Martin looking to cut 600 jobs from its production line in Gaydon, in Warwickshire.

Engineering firm Prodrive is facing more than 180 job losses too after the withdrawal of the Subaru World Rally Team which it prepared.

Richards defended the decision to compete in the world's most famous endurance race.

"Aston Martin, despite the downturn in the market for everybody, has been profitable for the past four years. Sometimes you need to do things like this to corral everyone's enthusiasm," he said.

More than 250,000 motorsport fans normally make the pilgrimage to the track in the Loire, to the south west of Paris.

German manufacturer Audi have won the race for the past five years but following rule changes this year's race over 13/14 June is expected to be a much tighter affair.

"A win at Le Mans - well, let's not be totally dreaming here but let's suppose we could be there at the podium at the finish, it would be a magnificent achievement for everybody," added Richards.

The last British team to win the Le Mans 24 Hours race was Bentley back in 2004.

»»  read more

New Highly Efficient Scuderi Split Cycle Air Hybrid Engine

Scuderi's new Split Cycle Air Hybrid Engine


Scuderi Group in West Springfield, Massachusetts, has recently developed the "Scuderi Split Cycle Air Hybrid Engine" (catchy i know). It is effectively a split-cycle internal combustion engine, but its revolutionary design has modified the common Otto cycle and instead of being only 33% efficient as most engines are, this new system is (in testing) claiming to reach efficiency levels of 40% far and above any other internal combustion engine, and best of all at this level up-to 80% of the toxic and atmosphere damaging gases are not present.

The initial invention was by Carmelo J. Scuderi and apart from the new stroke system, has a range of features to increase power output. One is a hybrid air system which takes energy from braking and stores it compressed air which can be then used in the engine or other areas of the car, to boost efficiency.

So how does it work? The conventional system runs on a four stroke cycle this new system split up this cycle into across two cylinders, one for compression and one for power. The gas is compressed in the compression cylinder and travels through an inlet passage to the power cylinder where it is ignited. The gas passage contains a series of uniquely timed valves which maintain the pressure in the gas throughout all four stages of the cycle, as the power piston moves to top dead centre of its cycle the gas is released into the power cylinder and fired to induce the power stroke. a very good animation of the system can be found here: http://en.wikipedia.org/wiki/File:Scuderi_Split_Cycle_Engine _-_Cycle.gif (or at the top of this post if the animation plays properly!)

By splitting the cycle the Scuderi engine brings a number of advantages to its unique system. The dedicated cylinders can be optimised for the job they are doing as opposed to being multi-tasking like in a normal engine, this boosts their efficiency and it make their engine different to any other around. This means the power stroke is longer and the gases thermal efficiency increases (see the Miller Effect), the compression cylinder can be made wider and as such supercharging the gas in the power piston, increasing power. On top of this the cylinders can be offset at almost any angle to maximize mechanical efficiency and placement within the vehicle.

The key features of it are that:

1. has an exceptionally fast combustion rate
2. a large increase in thermal efficiency
3.a large reduction in NOx emissions (Nitrogen Oxide)

for greater detail there is a breakdown of all the stages and detailed explanations at http://www.scuderigroup.com/technology/theory_of_operation.html

The engine already has 35 issued patents and 60 patents pending in over 50 countries related to the design on the engine, including: Cargine Engineering (Sweden), Gates Corp (Denver), Schaeffler Group (Germany) and the engineering division of Germany's Robert Bosch GmbH.

Overall this engine design is an exciting new development in the world of cars, it could revolutionize the four stroke cycle which has been pretty much unchanged for the best part of 100 years

»»  read more

Car Reviews

The page collects together all of the popular Car Reviews on Motorsport Zone into one place.

FORD FOCUS REVIEW - CLICK HERE

MAZDA 3 REVIEW - CLICK HERE

BMW i8 REVIEW - CLICK HERE

Car Reviews on Motorsport Zone are Sponsored by: Irwin Mitchell

If you have been in a car accident, and you want to find out more about how to make whiplash compensation claims, then visit www.irwinmitchell.com, who will be able to guide you through the next steps.

»»  read more