G'day Jack,
The Champion fan shroud looks well made ,it kind of looks factory made as it has no welding distortion in the sheet metal.
I think the back of the shroud with the flat section is open for the fan blades to stick out as the Champion
mower wasn't designed to push the air flow downward past the cylinder.
I don't think the Villager and the Victa fan mower were good designs as pushing air flow downward past the cylinder
with unshrouded engines and no way of having a leaf guard would result in leaves and grass accumulating in the
cylinders cooling fins causing the motor to run hotter.
The Champion Patent mentions - " Positioning of the fan relative to the motor as shown in Fig. 1 suffices to send a stream
of air about the motor which keeps it cool and keeps it cleared of grass clippings ".
The Champion fan blows away the rising heat from the cylinder just like the model 1 and 2 Rotomo because
these too are unshrouded engines ,the 1 and 2 Rotomo have a small fan shroud on the flywheel but nothing
to direct airflow down past the cylinder.
The 2a Victa with the full shroud directs air flow downward past the cylinder and when fitted with the first
style of recoil starter that is a close fit to the shroud this would act as a leaf guard but when Victa
changed the starter design to a higher mounted starter (ie bigger gap between the cowl and starter,
the only way to restrict leaves and grass entering the fan was to install a leaf guard .
Jack has written about the twin cooling Villager here
https://www.outdoorking-forum.com.au/forum/ubbthreads.php/topics/79433/VILLAGER_MOWERS_-_Twin_Cooling.htmlCheers
Max.
