This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Investigations of Valve Recession Mechanism in Flex Fuel Engines
Technical Paper
2011-36-0340
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
Valve recession is a phenomenon observed in internal combustion engines, in which the set of valve and valve seat presents excessive wear in the contact region, causing poor sealing of the combustion chamber and, hence, loss of engine power. It is known that the wear mechanism depends on several variables such as the fuel type. Because of the growing Flex Fuel vehicle sales and therefore the usage in large-scale of hydrated ethanol, it was necessary to perform new studies and actions for continuous improvement on engine optimization to minimize the valve recession levels. One alternative to expedite engine testing and follow valve recession is to run it on dynamometer and perform measurements of valve wear with pre-set frequencies. Based on the engine design, a maximum recession level is calculated and exceeding this number would cause stated failure modes. Supported by a 6-Sigma approach, distinct sources of degeneration of the valve set could be observed, which were consistently worsen by the usage of ethanol. This paper shows the study performed with the objective to reduce valve recession on Flex Fuel engines by experimentally evaluating combinations of valves and valve seats materials with different characteristics of hardness and heat dissipation, which, as observed, were the main factors influencing valve recession.
Recommended Content
Authors
Citation
Araújo, L. and De Paula Jr., G., "Investigations of Valve Recession Mechanism in Flex Fuel Engines," SAE Technical Paper 2011-36-0340, 2011, https://doi.org/10.4271/2011-36-0340.Also In
References
- Lewis, R. and Dwyer-Joyce, R. S., “Investigation of Wear Mechanisms Occurring in Passenger car Diesel engine Inlet Valves and Seat Inserts”, The University of Sheffield, Department of Mechanical Engineering, UK, SAE 1999-01-1216
- Clemente, Rafael C., Development of Internal Combustion Alcohol Fueled Engine, Ford Motor Company Brazil, SAE 2001-01-3917
- Sato, K., Development of Valve Seat Material for CNG Fueled Engines, Honda R&D Co., Ltd., SAE 2000-01-0911
- Menezes, C., “A Saga do Alcool”, Revista Carta Capital, p. 10-14, april 22, 2009.
- de Paula, G. A.Jr., Sagiorato, R. “Mapping Flex Fuel Fleet in Brazil Potentially Affected by Critical Conditions of Ethanol Cold Start and the Effects of a Fuel Heating Technology”, Ford Motor Company do Brazil, SAE 2009-36-0260.
- Szwarc, A., A Opção pelo Veículo Flex, Uniao da Indústria da Cana de Açucar - ÚNICA. Available at: www.unica.com.br/opiniao/show.asp?msgcode=%7bBF8E7F1F-1AD0-450D-901A-08B142E368F0%7d, 2002.
- Feitosa, M. V., Estudo da Partida a Frio em Motores Movidos a Etanol. EESC-USP, Sao Carlos, 1998.
- Hutcheson, R. C., Valve Seat Recession - An Independent review of Existing Data, Cameron Associates, SAE 2000-01-2015.
- Lopreato, L. G., Gasoline Lubricity Assessment through HFRR, Petrobras Research Center. 8th International Colloquium Fuels - Conventional and Future Energy for Automobiles, Stuttgart, Germany, 2011
- Siqueira Campos Associados, “Seis Sigmas - Conceitos Basicos”, 2010, book of training.