The magneto is driven by a gear having 36 teeth attached to crank-case which meshes with 16-tooth pinion on armature. The magneto turns at 2.25 times crank-case speed. Two cams, one for inlet, one for exhaust, are mounted on a carrying member and act on nine rocker arms which are capable of giving a push-and-pull motion to the valve-actuating rocker-operating rods. A gear driven by the crank-case meshes with a larger member having internal teeth carried by the cam carrier. Each cam has five profiles and is mounted in staggered relation to the other. These give the nine fulcrumed levers the proper motion to open the inlet and exhaust valves at the proper time. The cams are driven at 45⁄50 or 9⁄10 of the motor speed. The cylinder dimensions and timing follows; the weight can be approximated by figuring 3 pounds per horse-power.
| 80 | H.P. | 105 | M/M bore | 4.20′′ | bore. |
| 140 | M/M stroke | 5.60′′ | stroke. | ||
| 110 | H.P. | 112 | M/M bore | 4.48′′ | bore. |
| 170 | M/M stroke | 6.80′′ | stroke. | ||
| Timing— | Intake valve opening, lag | 18° | ⎫ | 110 H.P. | 18° | ⎫ | 80 H.P. |
| Intake valve closing, lag | 35° | ⎮ | 35° | ⎮ | |||
| Exhaust valve opening, lead | 55° | ⎬ | 45° | ⎬ | |||
| Exhaust valve closing, lag | 5° | ⎮ | 5° | ⎮ | |||
| Ignition time advance | 26° | ⎭ | 26° | ⎭ |
Fig. 224.—Diagrams Showing Valve Timing of Le Rhone Aviation Engine.
THE RENAULT AIR-COOLED VEE ENGINE
