Renault 100 hp V-12
| Industry | Automotive, Aircraft engines |
|---|---|
| Founded | February 25, 1899 in France |
| Headquarters | France |
The Renault 100 hp, also known as the 12B, was a twelve-cylinder, air-cooled V-engine with a 60° configuration, engineered by the French company Renault circa 1912.
Design and development
Building upon the earlier 90 hp Renault V-12, this model primarily featured an increased cylinder bore of 96 mm compared to the previous 90 mm, while maintaining much of the foundational architecture derived from Renault’s air-cooled V-8 engine series.
This V-12 engine incorporated two banks of cylinders set at a 60° angle, each cylinder having a bore of 96 mm and a stroke length of 140 mm. The cylinders and cylinder heads were manufactured as separate cast-iron components equipped with cooling fins; these were sealed using copper-asbestos washers and fastened to the crankcase by cross-shaped clamps.
Air cooling effectiveness was improved through a fan driven from the rear end of the crankshaft, which forced air into a chamber located between the cylinder banks and across the cooling fins.
A single camshaft positioned between the two cylinder banks controlled both intake and exhaust valves for each bank, with individual cams for each valve type. Intake valves were operated directly through tappets, whereas exhaust valves were actuated by pushrods and rocker arms. The propeller was mounted directly on this camshaft, which itself was geared down from the crankshaft via spur gears.
The engine’s oil reservoir was integrated into the base of the crankcase and supplied by a gear-driven pump powered off the camshaft. The crankshaft ran on five plain intermediate bearings and two ball bearings at its ends. Differing from its V-8 predecessors, this V-12 utilized master-and-slave connecting rods sharing common crank journals—a configuration that continued in subsequent Renault engines like the Renault 80 hp V-8 and Renault 130 hp V-12.
Pistons were crafted from steel and fitted with three cast iron rings. Fuel was delivered by dual carburetors, each servicing one bank of cylinders independently. Ignition relied on two Bosch magnetos mounted atop the camshaft, each magneto dedicated to one cylinder bank; both were driven through helical gears.
This powerplant achieved up to 110 hp at 1800 revolutions per minute.
Applications
- Astra C.M. hydroplane (participated in the 1912 Saint-Malo concours)
- Sanchez-Besa biplane (entered in the 1912 Saint-Malo concours)
Bibliography
External links
- Renault 100 hp V-12 engine installation (Gallica - BnF)
- Astra seaplane with Renault V-12 engine (Canada Aviation & Space Museum/Corbis via Getty Images)