Fiat AS.5
{{short description|1920s Italian piston aircraft engine}}
| {{Infobox Aircraft Begin
|name= AS.5 |image = |caption = }} {{Infobox Aircraft Engine |type= Piston V-12 aero engine |national origin = |manufacturer= Fiat |first run=c.1929 |major applications= Fiat C.29 |number built = |program cost = |unit cost = |developed from = |developed into =Fiat AS.6 |variants with their own articles = }} |
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.Gunston 1989, p. 57.
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.Eves 2001, p. 216.
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.Eves 2001, p. 217. The AS.5 was developed into the AS.6, essentially a tandem-coupled combination of two AS.5 units.
Applications
Specifications (AS.5)
{{pistonspecs
|
|type=12-cylinder V-engine
|bore=138 mm (5.4 in)
|stroke=140 mm (5.5 in)
|displacement=25.13 L (1534 cu in)
|length=
|diameter=
|width=
|height=
|weight=348 kg (767 lb)
|valvetrain=Two intake and two exhaust valves per cylinder
|supercharger=
|turbocharger=
|fuelsystem=Carburettor
|fueltype=
|oilsystem=
|coolingsystem=Liquid-cooled
|power=1,000 hp (750 kW) at 3,200 rpm
|specpower=
|compression=8:1
|fuelcon=
|specfuelcon=
|oilcon=
|power/weight=2.15 kW/kg (1.3 hp/lb)
}}
See also
{{aircontent
|see also=
|related=
|similar aircraft=
|lists=
|similar engines=
}}
References
=Notes=
{{reflist}}
=Bibliography=
{{refbegin}}
- 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}}
{{refend}}
{{Fiat aeroengines}}
{{Aeroengine-specs}}