High Speed Bottom End:
Single cylinder research engines have previously been limited to comparatively low speed operation due to the inherent out-of-balance characteristics of this configuration. This has restricted the correlation of results and data with normal engines running at higher speeds.
MAHLE Powertrain has now developed it’s proprietary, fully balanced, single cylinder bottom-end to further enhance test capabilities. The modular design allows high speed operation at up to 5000 rpm for optical engines and up to 8500 rpm for thermodynamic engines. This enables testing at representative engine speeds and also ensures enhanced accuracy of imaging and measurements during optical testing.
The high speed bottom-end can be configured for use with a wide range of engine types and is successfully utilised for advanced combustion development with both spark ignition and compression ignition cylinder heads. The versatile design allows quick change over of pistons for comparison testing of different compression ratios.
The MAHLE optical single cylinder engine is the ideal tool to investigate the spray and combustion characteristics of various fuels and biofuel blends in detail. Using this research engine, MAHLE Powertrain has conducted comprehensive investigations into Port Fuel Injection (PFI) and Direct Injection (DI) spray development and combustion imaging.
Video clip: balanced, high speed, single cylinder
The clip shows the new high speed single cylinder research engine running - with a 50p coin balanced on the top of the block to demonstrate that the engine is highly balanced. The demonstration begins with the engine being motored at 600 rpm and the speed is increased to 1200 rpm and then to 1800 rpm. The coin (a genuine 50 pence piece) begins to rotate, clearly showing that it has not been adhered to the engine in any way.