Mark Smith’s PME Engines of Mooresville, North Carolina powers the NASCAR Camping World Truck Series (CWTS) entries of Ron Hornaday Jr and Matt Crafton, currently first and second in points as the campaign hits its home stretch. To keep things consistent, there’s not much out of the ordinary that he’s ready to do with his Bill Miller and Mahle pistons at this point in the game. “We do a lot of testing with different moly coatings on the rings and ring lands,” he...
Mention the subjects of durability and wear measurement in engine development and the image immediately conjured up is one of tests lasting hundreds of hours and lots of precise measurements, both before and after the test. When it comes to the piston ring we might want to check the ring gaps both free and as installed, measure the weight as accurately as we can, take a few harness measurements and visually examine the wearing surface. Apart from that there is little extra even the...
Coatings to enhance both performance and longevity are the centre of focus in the world of racing piston manufacture today. To learn more, particularly in a NASCAR context, we talked with Brad Green, an engineer at Mahle Motorsports in Fletcher, North Carolina. According to Green, all their coating manufacture is performed in-house. This, he told us, can provide shortened lead times and reduced costs when compared to shipping pistons to outside coating sources. It also “gives us much...
Selecting a suitable piston ring coating is, dare I say it, rather like choosing a wife. Selected in haste, the time could come when you repent at leisure and very much like choosing a mate, under times of great stress, the issue is one of compatibility. It has long been acknowledged that the piston ring, particularly the top ring, has one of the most arduous tasks in the internal combustion engine. Having to seal the gap between the piston and bore from the passage of unwanted blow-bye...
It has taken about two to three years of trial and error, but one American manufacturer believes they have found a new family of aluminium metal matrix materials for use in piston manufacturing. Rather than the customary silicon carbide matrix, a material that has a tendency to wear out manufacturing tools and has extremely sharp edges, this exclusive material consists of spheroidal aluminium oxide AI203 particles, randomly distributed as its reinforcement. This allows the machining...