Work Package 1 was the preparation phase, where the existing engine was examining and discussions help with the supplier about know weak points. Some preliminary FEA stress analysis was carried out on a couple of engine components to understand the potential challenges and opportunities for weight reduction. Using this information and via regular meetings with the engine supplier and detailed scope of work was defined and a project timing plan produced.
Work Package 2 was the main technical phase of the project where the engine components defined in WP1 were redesigned to improve their strength and reduce their mass. An alternative method of construction was utilised for the main engine crankcase, this was done to improve its strength as well as simplify the manufacturing of the part. The cylinder barrels very also redesigned around an alternative manufacturing method as these parts were targeted as the item with the largest potential for weight saving. A by-product of the alternative design was also an improvement in the cooling of the cylinder barrels. The cylinder heads were redesigned to reduce their mass and CFD analysis was carried out to also improve the cooling of these parts. A number of smaller components were also redesigned to reduce mass and accommodate the changes made to the other engine components. The FEA stress analysis showed that all components could achieve the desired engine life at the increased loads for the project. The CFD results also demonstrated improved cooling for the engine which would also have a positive impact on the engine durability.
Work Package 3 was the manufacture of parts to the new design so that a prototype engine could be assembled and tested in Work Package 4. Castings were procured for the major structural components of the engine and as of the end of Reporting Period 1 ( 30/6/17 ), the castings had been received and they were part way through the process of being machined into finished components.
During Reporting Period 2, the machining of all crankcase, cylinder barrel and cylinder head castings was completed at Ilmor. For the cylinder barrels this also meant sending the parts to an external supplier for plasma spray coating the bore, then to the honing supplier.
Two cylinder heads and barrels were machined to accept thermocouples (37 per cylinder), to allow temperature measurement during engine testing. The majority of other components were manufactured by companies within Ilmor’s supplier base.
Work Package 4 comprised the assembly, testing and final inspection of the engine. The engine was assembled at SMA with the aid of an Ilmor prepared build manual. Engine testing took place at external test facility. The engine completed a running-in cycle, then performance characterisation and thermal testing, at the desired power output. Further testing included a durability cycle which brought the total engine test duration to 96 hours.
The engine was returned to SMA for disassembly and inspection. The majority of new parts were also returned to Ilmor for more detailed analysis.
The complete prototype engine, despite being designed to cope with higher combustion pressures and temperatures was 5.4Kg lighter than the existing engine.
Ilmor will disseminate information regarding the details of the project to the wider aerospace community via a dedicated section on the ilmor.co.uk website. In addition, an aerospace specific PR company will put together a press release, and create a technical article detailing the novel features introduced to the prototype engine. This will be published in one of the leading aerospace media publications.
