The world’s first 2-cylinder turbocharged diesel engine will take to the roads of India next year, heralding a new chapter of ultra-fuel efficient micro vehicles in the story of automotive design. The 0.8L engine, boosted by Honeywell’s smallest-ever turbo, will power a new breed of ‘last mile’ delivery vehicles bustling through the busy streets of the sub-Continent’s cities and towns, typically carrying goods from warehouses to local businesses. It also heralds the imminent arrival of a new category of small, turbocharged passenger cars equipped with engines of a similar size.
For Honeywell, the program was an opportunity to introduce more power to a vehicle category where fuel efficiency rules supreme. Turbocharging such a small engine created a whole new set of challenges that result from dealing with the unique characteristics of two-cylinder engines.
“The issues in developing a turbo for a 2-cylinder engine not only revolve around packaging but also around specific challenges linked to compressor surge, oil leakage, high vibrations and high thrust load due to engine pulsations. These issues are far more pronounced here than in a four-cylinder engine,” says Vijayan Asvathanarayanan, Director of Application Engineering for Honeywell Turbo Technologies in India.
This meant that Honeywell engineers had to approach the turbo design from a completely novel angle. They began by proactively testing a 2-cylinder engine to assess the engine specific risks for turbocharging; well in advance of formal development work.
“We came up with a totally new turbocharger that included a very small turbine housing with integrated manifold, and the smallest-ever compressor wheel developed by Honeywell. The higher relative thrust loads brought about by the pulsation of a bi-cylinder engine meant creating new concept thrust pads in the Z-bearing – vital if we are to be efficient in matching the turbo to the engine requirements.”
A high-efficiency, compact bearing was developed for this engine configuration, and the bearing design is so successful that it is now being extended to other turbo sizes as well.
Honeywell’s global community of engineers worked closely with the auto manufacturers’ team to address the specific issue of engine surge, which would otherwise disrupt the efficient performance of the turbo.
Specifically, Application engineers in Pune and Product engineers in Bangalore – the company’s center of excellence for micro-turbo technology – collaborated with colleagues in Thaon-Les-Voges in France, utilizing many of the world’s most advanced turbo tests and simulation facilities.
The result of all this intense activity is a well-performing and reliable turbo for a new engine platform, due for release and production in 2011. This Honeywell-boosted 2-cylinder diesel engine from a major Indian OEM offers a remarkable 25% improvement in power over a non-turbo equivalent, along with significant fuel efficiency gains and lower emissions.
Critically, the success paves the way for the roll-out of a new generation of boosted 2 and 3 cylinder diesel passenger cars and light commercial vehicles, particularly in emerging regions.
“This engine program has created a new higher performing small engine segment where turbocharging can deliver the performance edge while maintaining the superior fuel-efficiency benefits,” says David Paja, Vice President of Marketing at Honeywell Turbo Technologies. “It has established Honeywell’s class-leading capability to serve small engine segment with performing, efficient and cost-effective wastegated turbochargers both in India and in other parts of the world.”