microflex® 978 Combustion Chamber Cleaner: How to Effectively Avoid Low-Speed Pre-Ignition (LSPI)
What Does Low-Speed Pre-Ignition Mean and How Does It Occur In the Combustion Chamber?
In Low-Speed Pre-Ignition (LSPI) in petrol engines with direct injection the fuel-air mixture ignites without being triggered by the spark plug. This unscheduled combustion causes extreme pressures in the engine and – depending on the design – can cause serious damage or even completely destroy the engine the first time it occurs. Essentially, low-speed pre-ignition has two causes:
- Fuel-oil drops and
- Red-hot particles
- Causes > Fuel-Oil Drops
- Causes > Red-Hot Particles
- Causes > Inconsistent Driving Profiles, Fuels & Engine Oils
- Result > Low-Speed Pre-Ignition
- Video > Prevent LSPI With microflex® 978 Combustion Chamber Cleaner
- Problem > Increased Risk Of Damage For Petrol Engines
- Solution > Prevent LSPI In the Combustion Chamber
- Before-After Comparison > Cleaning the Piston Head
Expert Guidebook Low-Speed Pre-Ignition (LSPI)
As a result of fuel being injected into the cylinder, the cylinder wall, which is lubricated with oil, is covered with fuel. This creates a mixture of oil and fuel from which drops can be released during the compression phase. This fuel-oil mixture has a higher combustibility than pure petrol.
At higher pressures and increasing temperatures these drops can self ignite, which, ultimately, can trigger low-speed pre-ignition of the entire fuel-air mixture in the combustion chamber.
In addition to the gaseous fuel-air mixture, the combustion chamber can also contain particles or deposits of solid substances. These can loosen as a result of vibrations or fuel injection. The freely moving particles absorb heat in the combustion chamber and cannot dissipate this heat via the walls or components.
If the temperature is sufficiently high, these red-hot particles can also cause premature injection.
Inconsistent Driving Profiles, Fuels and Engine Oils
In modern petrol engines, deposits or particles in the combustion chamber are almost impossible to prevent.
The reasons for this include very different driving profiles by the drivers and very inconsistent compositions of fuels and engine oils.
Low-Speed Pre-Ignition (LSPI)
As a result, these influencing factors can lead to sooty combustion or oil contamination in the combustion chamber. The resulting soot or oil particles accumulate on the walls or components, such as pistons or injectors. Vibrations or fuel injection can loosen these particles and cause them to become red hot.
If the particles are large enough that they do no extinguish in good time, they can cause premature ignition of the fuel-air mixture – with the described consequences.
Preventing LSPI With microflex® 978 Combustion Chamber Cleaner
Increased Risk Of Damage For Newer Generation Petrol Engines
Special Features Of Modern Direct Injection Engine
- Smaller engine size
- Heavy loads
- High average pressures
- Low engine speeds
All of these factors increase the risk of damage to petrol engines in modern vehicle generations. This risk can be reduced considerably by using microflex® 978 Combustion Chamber Cleaner.
Effective Prevention Of Low-Speed Pre-Ignition (LSPI) In the Combustion Chamber
978 Combustion Chamber Cleaner
- reduces deposits on the piston head,
- on the injector and in the combustion chamber,
- reduces damaging pre-ignition,
- uses no metal ingredients,
- is suitable for all petrol (ethanol) engines.
Drivers can simply put the additive into the vehicle tank. The following filling intervals should be complied with:
- < 10,000 km/year: microflex® 978 every 3 months
- > 10,000 km/year: microflex® 978 every 6 months