High performance polymers supplier Solvay has announced that that its AvaSpire AV-651 CF30 polyaryletherketone (PAEK) will form three sections of the Polimotor 2 engine's external dry sump modular oil pump housing.
The Polimotor 2 project, led by Matti Holtzberg, who invented the Polimotor 1, aims to design and manufacture a next-generation, all-plastic engine for competitive racing later this year.
“Solvay's unmatched selection of specialty polymers offered several possible options for replacing the typically aluminum pump components, including its high-performing Ryton PPS and KetaSpire PEEK products,” says Holtzberg, who is also president of US-based Composite Castings. “But we found that this particular grade of AvaSpire PAEK delivered the targeted weight reduction with an optimal balance of toughness, dimensional stability and other qualities required to successfully withstand the rigours of the Polimotor 2's oil pump.”
The oil pump housing will encounter oil temperatures approaching 140°C (284°F) and internal pressures cycling between 2.8 and 5.5 bars.
Each of the three injection-moulded sections weighs 0.09kg compared to 0.19kg for their aluminum counterparts. Overall, replacing the entire metal housing with one moulded from AvaSpire PAEK delivered a total weight reduction of 0.27kg, while meeting the desired performance requirements of the oil pump.
A 30% carbon fibre-reinforced compound, AvaSpire AV-651 CF30 PAEK delivers higher strength, stiffness and fatigue resistance compared to base AV-651 grades, and enhanced weight reduction versus glass fibre-reinforced AvaSpire PAEK grades. The material's long-term thermal oxidative stability approaches that of carbon fibre-reinforced PEEK, but it delivers better dimensional stability and warp resistance during injection moulding.
US-based Molding Concepts injection moulded the three net shape parts. They were then machined by Allegheny Performance Plastics, a US processor of high-performance thermoplastics.
Greg Shoup, president of Allegheny Performance Plastics, says: “The excellent machinability of AvaSpire AV-651 CF30 PAEK enabled Allegheny to achieve the extremely tight tolerances necessary for the pump's gear tip clearance and sealing surfaces, while achieving very good surface finishes.”
Brian Baleno, global automotive business development manager for Solvay Specialty Polymers says: “AvaSpire PAEK offers the most optimal balance of toughness and elongation within our specialty polymers portfolio, which is prompting evaluation of these polymers for use as vacuum pump vane tips, bearing cages and cable ties.”
The Polimotor 2 project aims to develop an all-plastic, four-cylinder, double-overhead CAM engine that weighs between 63-67kg, or about 41kg less than today's standard production engine.
Holtzberg's programme will leverage Solvay's advanced polymer technologies to develop up to 10 engine parts. In addition to the oil pump components, other parts include cam sprockets, fuel assembly components, O-rings, water cooling fixtures, throttle body parts and other high-performance components.
Other Solvay materials targeted for use include Amodel polyphthalamide (PPA), KetaSpire polyetheretherketone (PEEK), Radel polyphenylsulfone (PPSU), Ryton polyphenylene sulfide (PPS), Torlon polyamide-imide (PAI) and Tecnoflon fluoropolymer (FKM).