SNECMA Régnier 4L
| Industry | Aircraft engine manufacturing |
|---|---|
| Founded | 1930s |
| Fate | Nationalized and integrated into SNECMA around 1946 or 1947 |
| Products | Aircraft engines, including four-cylinder air-cooled inverted inline models (e.g. R.4L-02, 4J, 4K, 4L series) |
| Parent | SNECMA (from ~1946/1947) |
The SNECMA-Régnier 4L represents a French-made, four-cylinder, air-cooled inverted inline piston engine that was introduced shortly following World War II.
Design and development
The Régnier Motor Company began manufacturing aircraft engines by obtaining licenses for the de Havilland Gipsy Major and Gipsy Six. Although initially inspired by de Havilland designs, Régnier eventually created their own original engines. By the mid-1930s, they had developed several four-cylinder air-cooled inverted inline models, including the R.4L-02 which was displayed at the 1936 Paris Air Show. Despite sharing a designation with the post-war engine, the 1936 variant produced power from approximately 4 liters displacement and weighed around , whereas the subsequent model delivered from 6.3 liters at .
Throughout the Occupation of France and in the years after the war, Régnier engineered three simplified versions of four-cylinder inverted air-cooled inline engines—the 4J, 4K, and 4L—each with progressively larger capacity and increased output. The specifications of the post-war 4L closely resemble but do not exactly match those of the pre-war R.4; meanwhile, the earlier R.4L is more comparable to the later 4K model. Around 1946 or 1947, Régnier was nationalized and integrated into SNECMA, which maintained production of the extensively used SNECMA-Régnier 4L series.
Common construction elements shared with the 4J and 4K included steel cylinder barrels that were machined and coated with a baked-on anti-corrosion varnish, separate cylinder heads sealed using metallo-plastic gaskets fastened by long bolts, as well as aluminium-bronze valve seats and spark plug bushes. The crankshaft was a five-bearing forged steel component housed within an aluminium alloy crankcase, while duralumin connecting rods featured split steel-backed bronze bearings.
Production of the 4L series by SNECMA continued until at least 1956. The most notable use of this engine was in the military Nord NC.856A, with a total of 112 units manufactured.
Variants
Information sourced from Jane's All the World's Aircraft 1956/57. Variants are also identified as 4LO-4, etc.
- 4LO
- Initial post-war designation
- 4L-00
- First post-war model delivering maximum continuous power at 2,280 rpm.
- 4L-02
- Increased compression ratio of 7.25:1, maximum take-off and continuous power at 2,500 rpm.
- 4L-04
- Similar to 4L-00 but featuring rearranged accessory layout.
- 4L-06
- Based on 4L-02 with modified accessory placement.
- 4L-08
- Comparable to 4L-04 but with a higher compression ratio of 6.8:1 producing maximum take-off and continuous power.
- 4L-14
- 4L-20 to 4L-34
- Versions adapted for inverted flight corresponding to base models (-00 through -14).
Applications
Information derived from: Gaillard (1990)