OutdoorKing Repair Forum Forums The History Forum Model Histories ENGINES POPE - Rotary Valve 2-stroke - c1957

Hello ODK history lovers
When Pope entered the Lawnmower market in mid-1949, they
offered brilliant, modern designs for human-propelled reel push
mowers. These were the beautiful Wimbledons.

Within a short time, they were offering powered reel mowers –
The brilliant electric Centre Court of 1950, and then the first
petrol-powered reels in 1954.

Pope’s first petrol-powered engines were not made by Pope.
These were the Australian W. Will’s 2-strokes and then the British
JAP engines.

When Pope entered the rotary lawnmower market in 1957, they
offered an engine of their own manufacture. This was the 125cc
Rotary Valve 2-stroke.

This was a great design ...



What is a Rotary Valve 2-Stroke?
Pope was always a competitive company and it had a proud tradition
as a market leader in irrigation. If Merv Richardson and John Boundy
could make their own lawnmower engines, then Pope could too!

Pope claimed that the rotary valve design had a clear advantage
over the loop-scavenge designs used by Victa and Boundy engines.

A rotating valve in the crankcase would eliminate the drawbacks
(pun intended) of a piston acting as a valve for mixture intake.

Pope’s explanation is presented in the following gallery.

TO BE CONTINUED …

PART TWO - Pope Rotary Valve.
ODK is lucky to have a pretty good record of the Rotary Valve engine.

Member Chris125 has given us a great visual record ...
https://www.outdoorking-forum.com.au/forum/ubbthreads.php/topics/59799/1.html

Note that the fuel charge would enter the bottom crankcase
via a manifold and hollowed crankshaft. The fuel would then
be scavenged via cylinder ports to the combustion chamber.

The rotary valve and intake are clearly visible here ...

TO BE CONTINUED ...

PART THREE – c1960 Engine Manual – Intro
Here I present an Engine Operator Manual for Pope’s first engine –
their 125cc Rotary Valve 2-stroke.

This is a comprehensive manual covering operating, maintenance, repair and parts.

This is the second manual on the Pope Model 320 I have
presented on these great forums. The first one presents as the
original 320-02 Manual, a large illustrated manual that probably
covered Model 320-02 thru Model 320-04.

A link to the earlier manual can be found HERE.

This later engine manual I date to 1960-61, when the
320-05 and 320-6 were introduced.



This would make the engine the 500-05-708 …



Design changes must have been happening quickly at Pope,
and I have no doubt Pope’s eyes were clearly looking at
Victa’s new models for this season.

I say this because of the frenzied way the manual was modified
to introduce the new Impulse Starter, and other changes.

Note how the supplement ‘Care of Your Impulse Starter’
was crudely cut and inserted into the engine manual …



TO BE CONTINUED ...

PART THREE – c1960 Engine Manual – Part One
This rotary engine manual is one of the two booklets
that accompanied each new Pope mower in the early 1960s.

Note the rushed inserts: the notice pasted on the inside cover;
and the updated instructions on Page 11.

This was done to explain the changes made to the Model 320-05 and 06.
There was a new handle that replaced the original 'T' handle used on the
first rotary Popes.

Second, the snorkel was removed. These Popes had an on-board
torpedo-style air cleaner.

I have had to split the manual into two parts.
Here is the first part: -

This engine manual was part of an Operator Manual found here:
https://www.outdoorking-forum.com.au/forum/u...ator-manual-model-320-05-and-320-06.html


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