ILSAC To Add Timing Chain Wear Test To GF-6
Gasoline direct injection (GDI) and turbocharged GDI (GDI-T) engines are expected to capture 60 to 65% of the North American new passenger car market by 2019. GDI and GDI-T engines are headed for dominance and for good reason: better fuel economy, better torque, and better power from the same size engine versus indirect port fuel injection (PFI) engines. A turbocharged GDI engine can also be downsized and deliver the same peak power along with significantly better fuel economy.
Compared to PFI engines GDI and GDI-T engines have several unique features:
- increased production of fine carbon particulates during combustion which can enter the crankcase via blow by and cause excessive wear
- increased fuel dilution of crankcase lube oil (cylinder wall wetting by side-mounted direct fuel injectors allows fuel to contaminate the lube oil)
- increased A reaction occurring when oxygen attacks petroleum fluids. Oxidation is accelerated by heat, light, metal catalysts, and the presence of water, acids, or solid contaminants. Oxidation leads to increased viscosity and deposit formation. and deposits from higher operating temperatures and pressures
- higher initial cost than PFI engines for the higher-pressure fuel injection system
The one component that suffers the most from accelerated wear in GDI and GDI-T engines is the metal timing chain, which drives the camshaft(s) off of the crankshaft. Excessive wear can cause the check engine light to illuminate and could result in very expensive internal engine hardware repairs. Excess wear is evident in chain elongation which can disturb valve timing leading to degraded performance and higher engine out Mobile sources - Pollutant exhaust gases created by the combustion of fuel. Water and CO2 are not included in this category, but CO, NOx, and hydrocarbons are and are thus subject to legislative control. All three are emitted by gasoline engines, while diesel engines also emit particulates that are regulated. Stationary sources - The release of sulfur oxides and particulates from power stations that can be influenced by fuel composition. Local authorities control the sulfur content of heavy fuel oils used in such applications.. Researchers are not yet sure about the exact wear mechanism—it could be A type of wear scenario during which two surfaces in relative motion remove (or "abrade") particles from each other due to the presence of surface asperities or other particles. from carbon particles suspended in the lube oil or an interaction between carbon particles and the lubricant or both. A typical timing chain connecting the crankshaft and the overhead cams is shown below.
ILSAC has proposed a timing chain wear test for their new ILSAC GF-6 passenger car engine oil specification click here to view the draft specification proposed for first American Petroleum Institute. The primary oil and natural gas trade association in the United States. API operates a voluntary licensing and certification program that allows engine oil marketers to use the API Engine Oil Quality Marks if their products meet specific requirements. licensing in the first quarter of 2018. Ford is developing the chain wear test in a 2.0 L I-4 EcoBoost GDI-T engine. The wear test procedure is proposed to assure that International Lubricants Standardization and Approval Committee. A collaboration between the American Automobile Manufacturers Association (AAMA), Chrysler, Ford, GM, and the Japanese Automotive Standards Organization. ILSAC GF- engine oil specifications target fuel economy, emission system protection, and enhanced engine oil robustness. GF-6 engine oils can meet the timing chain durability requirements in GDI and GDI-T engines.
The rest of the world is faced with the same challenge. The ACEA. The primary automotive standards organization in the European Union. ACEA defines performance specifications for automotive oils, and the "ACEA" acronym is from the French (European Automobile Manufacturers Association (Association des Constructeurs Européens d'Automobiles). The primary automotive standards organization in the European Union, ACEA defines performance specifications for automotive lubricants.) is discussing the problem with counterparts in the oil and additive industry with a view of developing a suitable test in the future.
The timing chain is constantly facing unfavorable mixed and boundary layer lubrication regimes. Click video link below to learn more about boundary layer lubrication. Mixed and boundary layer lubrication regimes are not the ideal hydrodynamic lubrication regime where metal surfaces well separated by a protective oil film. GDI and GDI-T engine field experience shows in addition to timing chain wear more aggressive oxidation, A measure of a fluid's resistance to flow. A fluid with a higher viscosity flows less easily. gains, and related increases in A thin, insoluble, non-wipeable film occurring on interior engine parts. Varnish can cause sticking and malfunction of close-clearance moving parts. Varnish is called "lacquer" in diesel engines. deposits. None of this is good, so improvements in lubricant performance is necessary to enable the successful introduction of this new engine technology.
Lubrizol is developing high performance advanced additives packages for high performance GDI and GDI-T engine technology which will soon dominate the passenger car market. Lubricant additives can minimize wear, combat oxidation and control deposits. New lubricant chemical additives require development involving years of test results before commercialization. Given long lead times for lubricant product development, testing, and commercialization there is a growing urgency to proceed with the ILSAC and ACEA programs if the requested commercializations dates are to be met.