|Type||9-cylinder air-cooled radial aircraft engine|
|Manufacturer||Société Lorraine, Argenteuil, Paris|
|Major applications||Bloch 120|
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.
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.
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.
Most Algols were conventionally aspirated via a single carburetter 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.
- 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)
- 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
- Power output: rated 221 kW (296 hp)
- Compression ratio: 6:1
- 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.