Southfield, Michigan – A new aluminum piston design developed by parts supplier Federal-Mogul Corporation could potentially lead to smaller but more powerful diesel engines.
The design, called DuraBowl, results in significantly improved fatigue strength, with an extension of engine life as much as four to seven times that of a conventional cast piston.
During the last decade, typical performance outputs for automotive diesel engines rose from 67 hp/litre to around 70 hp/litre; the company said that with increasing pressure from legislative targets for CO2 reduction in most major global markets, the trend is likely to accelerate.
The combustion in a diesel engine takes place in a hollow bowl in the top of the piston, where temperatures can reach over 400 C, and pressure over 200 Bar. This can cause an increased failure factor in the rim of the piston bowl. Until now, the only potential solution has been fibre-reinforced pistons, which increase manufacturing complexity and cannot be reliably tested in a non-destructive way. With the new DuraBowl design, the cast piston is pre-machined, and the alloy around the rim of the bowl is re-melted and hardened to increase its strength and durability. The piston also lends itself to a simple test to ensure quality.
Federal-Mogul said the first application of the DuraBowl process is on a high-performance diesel engine recently launched for an unnamed “leading global vehicle manufacturer.”