World Library  
Flag as Inappropriate
Email this Article

Fiat AS.5

Article Id: WHEBN0024898013
Reproduction Date:

Title: Fiat AS.5  
Author: World Heritage Encyclopedia
Language: English
Subject: Fiat AS.6, Fiat Aviazione, Fiat A.50, Fiat 4700, Fiat AS.3
Publisher: World Heritage Encyclopedia

Fiat AS.5

Type Piston V-12 aero engine
Manufacturer Fiat
First run c.1929
Major applications Fiat C.29
Developed into Fiat AS.6

The Fiat AS.5 was an Italian 12-cylinder, liquid-cooled V engine designed and built in the late-1920s by Fiat especially for the 1929 Schneider Trophy air race.[1]

Design and development

For the 1929 Schneider Trophy contest Fiat planned a new seaplane to counter the British challengers from Gloster and Supermarine. To minimise frontal area they chose a compact V-12 engine design that set new size standards for a 1,000-horsepower (750 kW) class engine. This unsupercharged engine had a high power-to-weight ratio due to the use of a high compression ratio and a special fuel blend containing a 50/50 mix of petrol and benzole.[2]

A problem encountered with the AS.5 was that it developed maximum power at high crankshaft speeds (3,000 rpm) but lacked output gearing, so that great care had to be taken with the choice of propellers. The production version did feature a reduction gear.[3] The AS.5 was developed into the AS.6, essentially a tandem-coupled combination of two AS.5 units.


Specifications (AS.5)

Data from Gunston[1]

General characteristics

  • Type: 12-cylinder V-engine
  • Bore: 138 mm (5.4 in)
  • Stroke: 140 mm (5.5 in)
  • Displacement: 25.13 L (1534 cu in)
  • Dry weight: 348 kg (767 lb)


  • Valvetrain: Two intake and two exhaust valves per cylinder
  • Fuel system: Carburettor
  • Cooling system: Liquid-cooled


See also

Related development
Comparable engines
Related lists



  1. ^ a b Gunston 1989, p. 57.
  2. ^ Eves 2001, p. 216.
  3. ^ Eves 2001, p. 217.


  • Eves, Edward The Schneider Trophy Story. Shrewsbury. Airlife Publishing Ltd., 2001. ISBN 1-84037-257-5.
  • Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9
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.