MAHLE Powertrain’s latest development of its passive MAHLE jet ignition (MJI) technology can now be easily added into existing engine designs with only minimal changes to the final machining process.
Continued work throughout the lockdown period means that passive MJI can now be installed as a press-in unit into engines utilising an M12 sparkplug, or larger.
MAHLE Powertrain’s head of new technology and data management, Adrian Cooper said: “As the automotive industry seeks ways to unlock incremental efficiency and performance benefits from the internal combustion engine, jet – or pre-chamber – ignition technology is rising to the fore.
“We are beginning to see jet ignition being adopted into high-end production powertrains, such as Maserati’s recent Nettuno V6.
“We have worked with manufacturers and pinnacle motorsport such as F1 on the integration of this technology for close to ten years.
“However, our recent work on passive MJI makes the technology more accessible for adoption by mass-produced engines even as a retro-fit to existing designs, as part of a highly efficient powertrain.”
The passive MJI system features a small pre-chamber, which when ignited discharges extremely fast-moving, heated jets through a series of nozzles.
This provides multiple ignition sites within the main combustion chamber, which leads to rapid, highly stable combustion and significantly improved knock mitigation characteristics.
This enables the use of a higher compression ratio and in testing, up to a ten per cent reduction in fuel consumption has been measured.
“We have also used the opportunity during the pandemic to further develop the cold-start and emissions performance,” continues Cooper.
“Through careful development, we’ve been able to engineer a system that operates under these conditions without requiring a second ignition source, enabling the system to be applied to existing cylinder heads without the requirement for costly re-engineering.
“We have adapted an MJI-equipped production engine to start, run and perform reliably at -8 degrees C with equivalent catalyst light-off capability to conventional spark ignition.
“This is very encouraging, and we’ll be continuing development to lower this figure substantially.”