Michael (on the left) attempting to get the EXA running at the Uxbridge Ontario Steam Show. This EXA has has Wico ignition and is a single cylinder unit which in its past life would have powered a pumping unit as part of a friend sprayer. These engines are quite unusual in their design appearance and stand out amongst the many at shows. In the photo, the EXA is belted up to a slow running Farmall tractor which is turning it over while adjustments are made.
In this photo, the Exa is powering along on its own seeming to be running quite nicely. Uxbridge looks like a nice place for a show - the view of into the background of the nearby hills, nice green grounds.
When Michael visited Beth Dickinson, he took some photos of Dave's EXA show engine. Beth appears in some of the photos.
This photo of Dave's engine clearly shows the twin piston pump used to drive the sprayer. The pump unit is not directly coupled, but more on that later...
This is the head end of Dave's engine, showing the (probably) 3/4" Schebler mixer and Wico trip magneto. One of the unusual design features of the friend is that it does not use push rods to activate the valves, the motion is carried to the head end via gears and the valves are operated from a cam on a gear driven shaft. You might even go as far as saying this was one of the first overhead valve engines with gear driven timing (Japanese car makers eat your heart out :).
This is the tail end of the EXA showing the gear drive behind the flywheel - the bull gear on the left drives a shaft which passes under the cylinder to the pump unit on the other side of the engine.
This is the flywheel side of the EXA, showing the bull gear, spur gear driving the valve cam shaft and the governor also driven from the bull gear.
This is the twin piston pump mounted to the engine. The drive is not direct coupled. There is an eccentric shaft mounted on the main drive shaft. The eccentric is the driver for the pump. As it turns in its wide arc, it forces the piston pump back and forth. This motion is fairly slow and is clearly visible when the engine is running making for some interesting monkey motion for people watching the engine. These pumps are one of the reasons people are attracted to the EXA.
The photographs in this picture are © Copyright 2004 Michael Guy All Rights Reserved with the exception of the first one which is © Copyright 2004 David Ross All Rights Reserved. These photographs were submitted by Michael Guy and are used with his permission. Thanks for submitted the photos and your accompanying information and passing on the sad news about Dave.
Michael has his own pages on steam locomotives at Michael's Locomotive Pages.