Recreating the Wright R-1820 “Cyclone” (5)

In this post I will finish the first cylinder of the R-1820 “Cyclone”. It will be the “template” object, which I will clone eight times around the crankcase when I finish the other parts of this engine.

Although in my previous post the cylinder head received the full set of its cooling fins, it still lacks some details. One of them are the reinforcements of the valve covers:

Figure 87-1 Asymmetric reinforcements of the valve covers

As you can see, these reinforcements break the symmetry of the left and right valve covers. Both of them resemble a thick plate, but one is oblique, while the other is vertical. They are not the most prominent features of this cylinder head, and it took me some hours to determine their probable shape. Finally I classified them as the secondary features of the covers, which I have to recreate, for the assumed level of details.

Recreating the Wright R-1820 “Cyclone” (3)

One of the most prominent features of the R-1820 engine cylinders are their rockers. More precisely – their covers, cast as the part of the cylinder head (Figure 85‑1):

Figure 85-1 Cylinder valves and their rockers (a cutout)

The R-1820 was a classic four-stroke engine. Its cylinders had two valves: single intake valve, connected to the supercharger via a wide pipe, and single exhaust valve. Movements of these valves were controlled by cams, via pushrods and rocker arms mounted in the cylinder heads. The covers housing these valves and rocker mechanisms were placed on the right and left side of the cylinder head.