The internal combustion engine has been powering cars for well over a century now, and is thought to be in its twilight - but engineering breakthroughs are not a thing of the past just yet. Consider Porsche’s latest use of 3D printing for the pistons of its 911 GT2 RS, which has not only the enhanced the temperature management within the cylinders, but also increased the efficiency of combustion and delivered a stronger overall component. Consequently, it can access greater engine speeds and higher peak power, with the latter said to have jumped by 30hp thanks entirely to the use of the new manufacturing process. The post-production flat-six motor now has 730hp. Blimey.
Until now engine builders have always had to consider the limitations of the forging production process when designing pistons. But with 3D printing enabling the creation of practically any geometric shape via the additive manufacturing processes, which builds a piston up from the ground in layers of material, previously impossible features can now be added. The GT2 RS turbocharged flat-six’s pistons have gained integrated and closed cooling ducts, and they’ve become 10 per cent lighter in the process, too.
We know the astounding performance of the 991.2’s range-topping motor well; it supplies 553lb ft of torque from just 2,500rpm, with peak power coming in at 7,000rpm. It’s as elastic and explosive as petrol engines come, an engineering work of genius – and that was with the forged piston setup. Customer 911 GT2 RSs have all been delivered so this is very much a proof-of-concept project, but it’s one that affirms the opportunities for progress still present in the world of ICE development.
The 3D printing process used by Porsche is, as you might expect for such a cutting-edge tech, of the very latest, laser metal fusion kind. The system uses laser beams to heat and melt the powder surface into the desired shape. The system’s been developed with tech experts Mahle and Trumpf, with validation kit from Zeiss, so we’re inclined to believe Porsche’s claims for accuracy.
The manufacturer has already used 3D printing to replace classic parts that it no longer produces, but the thought of what might be possible elsewhere inside a flat-six is very exciting; the advantages of making engine internals lighter and stronger - and better designed - hardly needs further explanation. Of course the problems with producing components at scale in this fashion are not covered in Porsche's proof-of-concept, but then again it doesn't need to build too many to satisfy the next generation of GT buyers. The rest of us might have to wait a little longer...
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