Balancing Otto Engines

Florian Ion T. Petrescu(1*), Victoria Relly(2)

(1) Senior Lecturer at UPB (Bucharest Polytechnic University), TMR (Theory of Mechanisms and Robots) department, Romania
(2) Senior Lecturer at UPB (Bucharest Polytechnic University), TTL (Transport, Traffic and Logistics) department, Romania
(*) Corresponding author

DOI's assignment:
the author of the article can submit here a request for assignment of a DOI number to this resource!
Cost of the service: euros 10,00 (for a DOI)


Internal combustion engines in-line (whether working in four-stroke or two-stroke engines-Otto, Diesel, and Lenoir) are generally the most used. Their balancing problem is extremely important for their proper functioning. There are two possible types of balancing: static and dynamic. Total static balancing make that the sum of the forces of inertia of a mechanism be zero. There are also and a partial static balancing. Dynamic balancing means to canceling all the moments (loads) of the inertial of the mechanism. One mode of design of an in line engine, is the one with the gap between cranks of 180 [deg], or 120 [deg]. Another type of motor construction is the engine with opposed cylinders in line, called cylinder "boxers". In this type of engine (regardless of their position, which is most often vertical) for two-cylinder motor, one has a total static balancing and a dynamic imbalance. Similar to the model of masses concentrated in rotary motion, are solved and the balancing of the rotating shafts. An important way to reduce losses of heat engines is how to achieve a balanced best.
Copyright © 2014 Praise Worthy Prize - All rights reserved.


Internal Combustion Engines; Two Stroke Engines; Four Stroke Engines; Static Balancing; Dynamic Balancing; Forces of Inertia; Moments of Inertia

Full Text:



Antonescu P., Mechanisms, Structural and cinematic calculation. IPB publisher, Bucharest, 1979.

Artobolevski, I.I., Theory of mechanisms and machines. Scientific Publisher, Chişinău, 1992.

Fjoseph L. Stout – Ford Motor Co., I. Engine Excitation Decomposition Methods and V Engine Results. In SAE 2001 Noise & Vibration Conference & Exposition, USA, 2001-01-1595, April 2001.

Frătilă, Gh., Sotir, D., Petrescu, F., Petrescu, V., ş.a. Research on vibration transmissibility of the engine and the car body. In CONAT-matma, Braşov, 1982, Vol. I, p. 379-388.

Frătilă, Gh., Marincas, D., Bejan, N., Frătilă, M., Petrescu, F., Petrescu, R., Rădulescu, I. Contributions to the improvement of the suspension of the motor-transmission. Bulletin of University of Brasov, Serie A, Applied Mechanics, Vol. XXVIII, 1986, p. 117-123.

Froelund, K., S.C. Fritz, and B. Smith., Ranking Lubricating Oil Consumption of Different Power Assemblies on an EMD 16-645E Locomotive Diesel Engine. Presented at and published in the Proceedings of the 2004 CIMAC Conference, Kyoto, Japan, June 2004.

Grunwald B., Theory, calculation and construction of engines for motor vehicles. EDP Publisher, Bucharest, 1980.

Leet, J.A., S. Simescu, K. Froelund, L.G. Dodge, and C.E. Roberts Jr., Emissions Solutions for 2007 and 2010 Heavy-Duty Diesel Engines. Presented at the SAE World Congress and Exhibition, Detroit, Michigan, March 2004. SAE Paper No. 2004-01-0124, 2004.

Marincas, D., Sotir, D., Petrescu, F., Petrescu, V., ş.a. Experimental results on improved sound insulation cabin TV-14 vehicle. In CONAT-matma, Braşov, 1982, Vol. I, p. 389-398.

Pelecudi, Chr., ş.a., Mechanisms. EDP Publisher, Bucharest 1985.

Petrescu, F.I., Petrescu, R.V., Some design elements to improve motor mechanism. Proceedings of 8th National Symposium on GTD, Vol. I, p. 353-358, Brasov, 2003.

Petrescu, F.I., Petrescu, R.V., An original internal combustion engine. Proceedings of 9th International Symposium SYROM, Vol. I, p. 135-140, Bucharest, 2005.

Petrescu, F.I., Petrescu, R.V., Determining the mechanical efficiency of Otto engine’s mechanism. Proceedings of International Symposium, SYROM 2005, Vol. I, p. 141-146, Bucharest, 2005.

Petrescu, F.I., Petrescu, R.V., V Engine Design. Proceedings of International Conference on Engineering Graphics and Design, ICGD 2009, Cluj-Napoca, 2009.

Petrescu, F.I., Petrescu, R.V., Balancing thermal engines. Create Space publisher, USA, November 2012, ISBN 978-1-4811-2948-0, 40 pages, Romanian edition.

Taraza, D., "Accuracy Limits of IMEP Determination from Crankshaft Speed Measurements," SAE Transactions, Journal of Engines 111, 689-697, 2002.

Petrescu, F.I.T., Petrescu, R.V.V., Forces of internal combustion heat engines, (2014) International Review on Modelling and Simulations (IREMOS), 7 (1), pp. 206-212.

Petrescu, F.I.T., Petrescu, R.V.V., Determination of the yield of internal combustion thermal engines, (2014) International Review of Mechanical Engineering (IREME), 8 (1), pp. 62-67.


  • There are currently no refbacks.

Please send any question about this web site to
Copyright © 2005-2019 Praise Worthy Prize