MAHLE Continues Powertrain Downsize Project, Showcases Engine at Tech Center Opening - Engine Builder Magazine
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MAHLE Continues Powertrain Downsize Project, Showcases Engine at Tech Center Opening


To support the Grand Opening of the MAHLE North American Technical Center, Farmington Hills earlier this summer, one of the company’s Downsize Demonstrator Vehicles, powered by a specially designed research engine, was on hand to drive appraisals by the North American Automotive Press, multiple OEM customers and government agencies.

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In 2006, MAHLE Powertrain and its parent company MAHLE started the development of an in-house designed downsizing engine. The sole purpose of this was as a technology demonstrator and a marketing platform. The project advanced from a clean sheet design to running prototype in 12 months.

117738EBWebMahl_00000067704The 1.2L 3-cylinder engine program continued with development of intake, exhaust and boost systems through 2009, resulting in multiple technical publications and presentations at automotive conferences. The engine has also been used by MPT and some of its partners for research projects developing further advanced powertrain technologies.

In 2010, two engines were installed in demonstrator vehicles utilizing a bespoke single turbo boosting system developed by Bosch-MAHLE Turbo Systems and calibrated for driveability, emissions and fuel economy optimization.


To support the grand opening of the MAHLE North American Technical Center, Farmington Hills, MI, one of the Downsize Demonstrator Vehicles, equipped with a MAHLE Powertrain research engine, was  shipped from Europe and displayed for the North American Automotive Press, multiple OEM customers and government agencies.

Significant technical features of this vehicle include:
· A combustion system designed and optimized for high boosted central D;

· Through bolted block design for weight optimization and minimized bore distortion, thereby enabling the use of a low tension ring pack for further friction reduction;

· In-vehicle 30 Bar BMEP operation compared to 21-23 Bar for current OEM downsize product offerings;

· Split cooling system to lower cylinder head temperatures and support increased range of lambda 1 closed loop operation;

· MAHLE electronic wastegate control, enabling faster response time and greater resolution of the 3D boost map; and

· Electric water pump for faster warm up and lower parasitic losse.

Technical Specification
· Engine displacement: 1.2 L
· No. of cylinders: 3 in-line
· Bore/stroke: 83.0 / 73.9 mm
· Compression ratio: 9.3 : 1
·  Fuel injection: Multihole central DI
· Maximum power: 161hp @ 5000-6000 rpm
· Maximum torque: 211 lbft @ 1600-3500 rpm
· Torque at 1200 rpm: 119 lbft


According to its engineers, the Downsized Demonstrator Vehicle Project has been a great success and will now continue its development within MAHLE Powertrain to push the boundaries of downsized boosted powertrains even further.

About the MAHLE Advanced Downsizing Project
The downsizing of engines, especially gasoline, has now become firmly established as a proven approach for delivering significant fuel economy benefits.

The first generation MAHLE downsizing engine was developed using two-stage turbocharging to demonstrate the higher levels of performance that can be achieved, whilst still maintaining the inherent efficiency advantages of a small displacement unit.

This engine achieved or exceeded all its original targets with a power output very close to 200 bhp, a peak torque figure of 286 Nm, excellent flexibility (with 250 Nm available at 1,500 rpm) and a minimum Brake Specific Fuel Consumption (BSFC) of 235 g/kWh – all from a compact and lightweight 3-cylinder, all aluminum engine with a displacement of just 1.2 liters.


In order to provide a near-term production feasible solution and still deliver acceptable performance, the second-generation downsizing engine was designed with a single turbocharger from Bosch Mahle Turbo Systems (BMTS). Various other modifications were made to the engine configuration including a switch to the latest multi-hole solenoid fuel injectors along with the MED17 engine management system from Bosch.

This engine was further developed on the test bed throughout 2009 and some equally impressive performance figures were achieved, including a power output of 160 bhp and equivalent torque and fuel economy values to the first generation, twin-turbo engine.

The engine performance and flexibility were further optimized and the unit was installed in a production vehicle in mid 2010 to allow further driving development and calibration optimization. The demonstrator vehicle has recently completed an approved NEDC fuel economy test with CO2 emissions of 135 g/km – equivalent to 5.8 l/100km or ~49 UK miles per gallon. A number of further demonstrator cars have also been fitted with this special engine by MAHLE Powertrain for various customers.


A total of fourteen downsizing engines of various configurations have been constructed to date, with a number being tested and further developed at off-site locations. Certain engines are currently being used to assess the benefits of running on alternative fuels (such as ethanol and butanol blends) and to investigate future oil formulations.

The cylinder head and power pack from the MAHLE downsizing engine have also formed the basis for a new design of single cylinder research engine for advanced research into combustion system development.


For more information visit MAHLE Powertrain

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