HiI've recently have been reading up on the DC-3. Aside from the fact that the Cyclone is single-row and the Twin Wasp is double-row (and aside from the fact that the Twin Wasp sounds better), is there really any difference in the two radials from an engineering and pilot standpoint?

HiI've recently have been reading up on the DC-3. Aside from the fact that the Cyclone is single-row and the Twin Wasp is double-row (and aside from the fact that the Twin Wasp sounds better), is there really any difference in the two radials from an engineering and pilot standpoint?

I assume you're comparing the R-1830 (Twin Wasp) and R-1820 (Cyclone)? In this case, the row layout makes no difference outside of weight. The Twin Wasps weigh more. There aren't many other differences. The R-1820 came in many flavors with many different HP ratings, as did the R-1830. Both were wildly popular in their day.

Edited January 26, 201214 yr by ZachLW

Put a PT-6 on it!

Is there any special reason why the Twin Wasp has that awesome "Pratt and Whitney hum"?

Edited January 28, 201214 yr by squawkvfr

The sounds would be different because of the 14:9 difference in how often the cylinders fire, and because of differences in exhaust collectors and stacks.My understanding of the Cyclone vs Twin Wasp selection is that the DC-3 was designed around the Cyclone, but the Twin Wasp version was selected for the C-47 to help manage a broader war materials procurement situation. In 1942, the Cyclone was already going into the B-17, SBC, SBD and the Lockheed Lodestar/Hudson family of aircraft being produced for Lend-Lease customers. The R-1830 Wasp was being used in the soon to be replace Grumman Wildcat (continuing production would be FM-2 from GM using the Cyclone) and the PBY which were lower production volume. While the R-1830 Twin Wasp would eventually go into large numbers of B-24s, mass production of that aircraft had not begun to reach the scale of B-17 production. The P&W Twin Wasp was, at that time, a more readily available engine.Douglas built 600 some DC-3 aircraft before the war, many with the Cyclone, but everything after 1942 started out as a military variant (C-47, C-53, C-117, R4D) with the Twin Wasp, some 10,000 all told, before production stopped. Most DC-3s in civil use after the war were born as C-47 et al.The license built Lisunov Li-2 in the USSR used a Cyclone-like engine, i.e. the M-62 developed from the M-25, an earlier license built Cyclone. The license built L2D in Japan used locally-built Kinsei engines developed from a much earlier license for the P&W Hornet, a single row engine larger than the Wasp but smaller than the Cyclone.

The sounds would be different because of the 14:9 difference in how often the cylinders fire, and because of differences in exhaust collectors and stacks.My understanding of the Cyclone vs Twin Wasp selection is that the DC-3 was designed around the Cyclone, but the Twin Wasp version was selected for the C-47 to help manage a broader war materials procurement situation. In 1942, the Cyclone was already going into the B-17, SBC, SBD and the Lockheed Lodestar/Hudson family of aircraft being produced for Lend-Lease customers. The R-1830 Wasp was being used in the soon to be replace Grumman Wildcat (continuing production would be FM-2 from GM using the Cyclone) and the PBY which were lower production volume. While the R-1830 Twin Wasp would eventually go into large numbers of B-24s, mass production of that aircraft had not begun to reach the scale of B-17 production. The P&W Twin Wasp was, at that time, a more readily available engine.Douglas built 600 some DC-3 aircraft before the war, many with the Cyclone, but everything after 1942 started out as a military variant (C-47, C-53, C-117, R4D) with the Twin Wasp, some 10,000 all told, before production stopped. Most DC-3s in civil use after the war were born as C-47 et al.The license built Lisunov Li-2 in the USSR used a Cyclone-like engine, i.e. the M-62 developed from the M-25, an earlier license built Cyclone. The license built L2D in Japan used locally-built Kinsei engines developed from a much earlier license for the P&W Hornet, a single row engine larger than the Wasp but smaller than the Cyclone.

Thanks for the write up. Interesting stuff! Though this wouldn't mean a hill of blue beans to the pilot flying, It's interesting to see how the "competition" began.