The effects of engine oil additives on valve train wear

1989 ◽  
Vol 1 (4) ◽  
pp. 365-384 ◽  
Author(s):  
S. Shirahama ◽  
M. Hirata
Keyword(s):  
1983 ◽  
Author(s):  
Tomio Yoshihara ◽  
Tetsuo Wakizono ◽  
Hiromichi Hara ◽  
Eiichi Nakagawa

2014 ◽  
Vol 8 (1) ◽  
pp. 200-205 ◽  
Author(s):  
Kazushi Tamura ◽  
Toshimasa Utaka ◽  
Hideki Kamano ◽  
Norikuni Hayakawa ◽  
Tomomi Miyasaka ◽  
...  

Author(s):  
P. R. Norton ◽  
Gavin Pereira ◽  
Yue-Rong Li ◽  
Andreas Lachenwitzer ◽  
Masoud Kasrai ◽  
...  

The improvement of fuel consumption is an important driving force for research and development in the automobile industry in order to minimize greenhouse gas emissions as well as improving fuel economy. Aluminum alloys are a class of alternative materials that are being used to replace cast iron in motor components due to the concomitant weight savings which result in improved fuel efficiency, and cost savings. Our research focuses on these alternative Al-based alloys as well as traditional steel interfaces, and the protective films that form on the surfaces. Currently the zinc dialkyl-dithiophosphates (ZDDPs) have been used as engine oil additives for over 60 years. They are important chemically-active additives, known for their antioxidant and antiwear characteristics. ZDDPs are known to form a protective film (tribofilms) at rubbed surfaces, typically on iron containing metals surfaces commonly used in the automotive industry; however ZDDPs and the products formed are not well suited for the environment as they can readily poison the catalytic converters and their efficacy on Al-Si alloys is not well established.


2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Rupesh Roshan ◽  
Martin Priest ◽  
Anne Neville ◽  
Ardian Morina ◽  
Xin Xia ◽  
...  

Theoretical studies have shown that in severe operating conditions, valve train friction losses are significant and have an adverse effect on fuel efficiency. However, recent studies have shown that existing valve train friction models do not reliably predict friction in boundary and mixed lubrication conditions and are not sensitive to lubricant chemistry. In these conditions, the friction losses depend on the tribological performance of tribofilms formed as a result of surface–lubricant additive interactions. In this study, key tribological parameters were extracted from a direct acting tappet type Ford Zetec SE (Sigma) valve train, and controlled experiments were performed in a block-on-ring tribometer under conditions representative of boundary lubrication in a cam and follower contact. Friction was recorded for the tribofilms formed by molybdenum dithiocarbamate (MoDTC), zinc dialkyldithiophosphate (ZDDP), detergent (calcium sulfonate), and dispersant (polyisobutylene succinimide) additives in an ester-containing synthetic polyalphaolefin (PAO) base oil on AISI E52100 steel components. A multiple linear regression technique was used to obtain a friction model in boundary lubrication from the friction data taken from the block-on-ring tribometer tests. The model was developed empirically as a function of the ZDDP, MoDTC, detergent, and dispersant concentration in the oil and the temperature and sliding speed. The resulting friction model is sensitive to lubricant chemistry in boundary lubrication. The tribofilm friction model showed sensitivity to the ZDDP–MoDTC, MoDTC–dispersant, MoDTC–speed, ZDDP–temperature, detergent–temperature, and detergent–speed interactions. Friction decreases with an increase in the temperature for all ZDDP/MoDTC ratios, and oils containing detergent and dispersant showed high friction due to antagonistic interactions between MoDTC–detergent and MoDTC–dispersant additive combinations.


1999 ◽  
Vol 42 (4) ◽  
pp. 807-812 ◽  
Author(s):  
G. S. Kapur ◽  
A. Chopra ◽  
A. S. Sarpal ◽  
S. S. V. Ramakumar ◽  
S. K. Jain

1983 ◽  
Vol 26 (2) ◽  
pp. 189-199 ◽  
Author(s):  
Kiyoshi Inoue ◽  
Harumichi Watanabe
Keyword(s):  

1998 ◽  
Author(s):  
Koichi Kurono ◽  
Kenyu Akiyama ◽  
Miwako Shionoya
Keyword(s):  

1981 ◽  
Vol 24 (2) ◽  
pp. 101-107 ◽  
Author(s):  
Kiyoshi INOUE ◽  
Harumichi WATANABE
Keyword(s):  

1977 ◽  
Author(s):  
Kyozo Torii ◽  
Hitoshi Chida ◽  
Katsuji Otsubo ◽  
Yoshihiko Tsusaka

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