Lorraine Algol
The Lorraine 9N Algol was a French 9-cylinder radial aeroengine built and used in the 1930s. It was rated at up to 370 kW (500 hp), but more usually in the 220–300 kW (300–400 hp) range.
| Algol | |
|---|---|
| Type | 9-cylinder air-cooled radial aircraft engine | 
| National origin | France | 
| Manufacturer | Société Lorraine, Argenteuil, Paris | 
| Major applications | Bloch 120 | 
| Variants | Lorraine Sirius | 
Design and development
    
The Algol was a conventionally laid out radial engine, with nine cylinders in a single row. The crankcase was a barrel-shaped aluminium alloy casting, with an internal integral diaphragm which held the front crankshaft bearing. Forward of the diaphragm there was an integrally cast cam-gear case for the double track cam-ring. The reduction gear was housed under a domed casing attached to the front of the crankcase.[1]
Flange-mounted steel barrels were bolted to the crankcase and enclosed with cast aluminium alloy, screwed-on, cylinder head with integral cooling fins. The pistons were also made of aluminium alloy and had floating gudgeon pins. The nine pistons drove the single throw crankshaft via one channel-section master rod and eight circular section auxiliary rods. The master rod had an integral, split type big-end. The crankshaft was machined from a single forging, with bolt-on balance weights.[1]
The Algol had a single pair of overhead inlet and exhaust valves per cylinder. The cam-ring drove roller tappets, mounted in the cam-case, which in turn operated rocker arms, fitted with ball bearings, via pushrods. The cam-ring was concentric with the crankshaft and driven via epicyclic gears.[1]
Most Algols were conventionally aspirated via a single carburetter[1] but at least one 1938 variant used a form of fuel injection, where fuel was blown into the induction system rather than the cylinder head.[2]
Variants
    
- 9A
 - 9Ab
 - 9Ac
 - 9Ad
 - 9N Algol
 - 9Na Algol
 - 9N Algol-Junior
 - 9N Algol-Major
 - 9N Algol-Amelioré
 - Type 120 500 hp
 - A developed version with supercharger and reduction gear giving 500 hp (370 kW) at 3,000 m (9,800 ft)[3]
 
Applications
    
    
Specifications
    
Data from Jane's All the World's Aircraft 1938[1]
General characteristics
    
- Type: 9-cylinder single row supercharged radial
 - Bore: 140 mm (5.51 in)
 - Stroke: 150 mm (5.90 in)
 - Displacement: 20.78 L (1,268 cu in)
 - Length: 1.347 m (53.2 in)
 - Diameter: 1.275 m (50.2 in)
 - Dry weight: complete 390 kg (860 lb)
 
Components
    
- Valvetrain: one inlet and one exhaust overhead valve per cylinder, operated with rocker arms, pushrod driven via roller tappets bearing on a double track cam-ring
 - Fuel system: single Stromberg carburettor, heated by exhaust
 - Fuel type: petrol
 - Cooling system: air-cooled
 - Reduction gear: 11:17
 
References
    
- Grey, C.G. (1972). Jane's All the World's Aircraft 1938. London: David & Charles. pp. 48d–49d. ISBN 0-7153-5734-4.
 - "To Paris". Flight. No. 8 December 1938. p. 534.
 - Société Nationale de Constructions de Moteurs: Argentuil (in French). Argentuil: SNCM. November 1938. Archived from the original on 16 October 2014. Retrieved 11 October 2014.
 - Parmentier, Bruno. "Sema 12". Aviafrance. Retrieved 14 October 2012.