World Library  
Flag as Inappropriate
Email this Article

Mean piston speed

Article Id: WHEBN0003153971
Reproduction Date:

Title: Mean piston speed  
Author: World Heritage Encyclopedia
Language: English
Subject: Piston engines, Wärtsilä-Sulzer RTA96-C, Multi-cylinder engine, Sprint Cup Series, WikiProject Automobiles/Articles
Publisher: World Heritage Encyclopedia

Mean piston speed

The comparison of mean piston speed (black line) with real piston speed (color lines). Diagram shows one stroke from BDC to TDC. Revolution = 1.000 min-1, stroke = 88 mm. The connecting rod ratio l/r varies: 3 - red, 4 - green, 5,5 - blue

The mean piston speed is the average speed of the piston in a reciprocating engine. It is a function of stroke and RPM. There is a factor of 2 in the equation to account for one stroke to occur in 1/2 of a crank revolution (or alternatively: two strokes per one crank revolution) and a '60' to convert seconds from minutes in the RPM term.

MPS = 2 * Stroke * RPM / 60

For example, a piston in an automobile engine which has a stroke of 90 mm will have a mean speed at 3000 rpm of 2 * (90 / 1000) * 3000 / 60 = 9 m/s.

It is a good indicator of the class and performance of an engine relative to its competitors. Honda S2000 had the highest piston speed for any production car (25.2 m/s) until the B7 Audi RS4 (2006-2008) debuted. This Audi was powered by a 4.2-liter naturally aspirated V8 (92.7mm stroke; 8250 RPM redline), resulting in a mean piston speed of 25.5 m/s. The Audi was in turn beaten by the 2015-2016 Ford Mustang Shelby GT350, which has a 5.2-liter naturally aspirated V8 (93.0mm stroke; 8250 RPM redline) with a mean piston speed of 25.6 m/s.

Corrected Piston Speed Frederick Lanchester and Janke and King

Corrected Piston speed is a method to more accurately represent stress on an engine, and is calculated as

mean piston speed divided by the square root of the stroke/bore ratio Classic Racing Engines Karl Ludvigsen (Glossay)


low speed diesels
~8.5 m/s for marine and electric power generation applications
medium speed diesels
~11 m/s for trains or trucks
high speed diesel
~14 m/s for automobile engines
medium speed petrol
~16 m/s for automobile engines
high speed petrol
~20–25 m/s for sport automobile engines or motorcycles
Some extreme examples are NASCAR Sprint Cup Series and Formula one engines with ~25 m/s and Top Fuel engines ~30 m/s

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.