Tuesday Torque: The Collis Is Highly Unusual And Very Collectible

The Collis is a very rare engine, and it is one that Cushman collectors salivate over. It came out in 1920, and there were only about 800 of them made. Cushman licensed it to be built as the Pierson engine, and there are a few out there with that name. The Collis was a big departure from the typical farm engine of 1920. It turned much faster, was lighter for the horsepower, it had a counterbalanced crankshaft, and it had a radiator instead of a water hopper. Updates came quickly and the rotating radiator disappeared, replaced by a radiator behind the flywheel, which acted as a fan and pulled air through the radiator. The single rocker arm that worked both the intake and exhaust valve was a huge innovation in 1920. Typical farm engines at the time ran at half the speed or less of the Collis, and they used an atmospherically operated intake valve. That wouldn't work at higher speeds, thus the cam-operated intake valve had to be used. This design was meant to be used for orchard sprayers and binders to cut and bundle wheat and oats, and it was much lighter than engines that were being utilized at the time. I think that most of these engines probably failed when the rotating coupler leaked, letting the cooling water escape. That could drain the system quickly if the operator wasn't looking. If you run across one of these that can be restored, grab it. There are very few in captivity that run, and Cushman collectors want them.