A Reader Responds

By Staff
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Reo lawnmowers, from left to right: Model 211, Type H, Reo Royale; Model 552, Type A, Reo Royale; Model 552, Type A (late), Reo Runabout. These lawnmowers are all in original condition.
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1947 Wheel Hone tractor. The wrap-a-rope starter was replaced with a recoil starter from a later engine for ease of operation (the tractor sees plow duty all winter). Reo engine model 211.
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Continental Model AU on David Bradley tractor (1956).
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26 Mott Place, Rockaway Boro, ‘New Jersey 07866

The following three articles were written in answer to readers
and questions which appeared in the Reflections column in the March
1986 issue of GEM. It is hoped that Mr. Mackey’s detailed
information will be helpful to other readers.

The first two articles deal with the question from Hugh E.
Porter, RR 1, Box 274, Dallas City, IL 62330: ‘How many models
were made of the small Reo and Continental engines, and where might
we locate manuals for same?’

Reo Engines

The Reo 45° bank 1-cylinder engine (cast iron) was made from
approximately 1947 to 1958. It departed radically from the accepted
designs of the times in which it was built. It is the only small
1-cylinder 4-cycle engine that runs counterclockwise. The cam and
valve arrangement was unique (see diagram) and the camshaft was
also the sole power takeoff point except for one example that had
an extra reduction built in.

These small but strong engines were made with many variations.
Some were minor, like a different carburetor or fuel tank. Others
were major, such as a change in bore and stroke, or the placement
of a recoil starter (with a stainless steel pull cord) instead of
the standard ‘wrap a rope’ setup.

There are 3 major 45° engine types. First, the most common, is
the ‘regular’ 45° engine. This engine was mostly put on Reo
reel type lawn mowers, called the Reo Royale (early) and the Reo
Runabout (later). I own about 8 of these engines and no two are
exactly alike. The later engines almost always had the recoil
starter. The second type was still a 45° bank engine, but had an
extra gear reduction built into the timing case. This produced a 7
to 1 ratio at the output shaft. These were used on a 2 wheeled
garden tractor built by Reo. The third type was again a 45° engine,
but this series was placed on its side to power a rotary lawnmower.
This mower was also built by Reo. I do not have specific
information on the third model as I do not own one (yet); however
they were only built during the last two years of the 45°
engine’s production. The crankshaft was vertical in this model;
on all others it was horizontal. I have only seen two examples of
this type engine.

In early 1957 Reo began building an aluminum block 4-cycle
engine under license to Tecumseh (an engine company still in
operation today). This engine looks like and runs like engines
still being built today. Also in 1958  Reo began production of
all types of gas powered equipment, using the ‘new’
aluminum engines. I still use a Reo snow blower built in 1959 
that my parents bought new that year, that has a ‘license
engine’ in it.

Although the Reo-built ‘license engines’ look the same
as the Techemseh engines built at the same time, they were in fact
different, and not very many parts were interchangeable. (A more
modern parallel is between the U.S.-built Wisconsin, and the
Japanese-built license the Wisconsin Robin engines: the same, yet
different.) Some parts are still available for the
‘license’ engines, if you have the model, type, and serial
numbers, from a Techemseh dealer. A good small engine shop should
be able to match up a set of points and a condenser for either
engine (the 45° will take time), and carb parts should still be
around too (although some of the 45° carbs are obsolete for
example, the Tillotson carb used on the 45° Model 404). No new
parts are available for the 45° engine.

Reo was a self-owned company until 1962 when it was bought out
by the Wheel Horse Company. The Reo company still operated as a
division of Wheel Horse until it was finally shut down in a
consolidation move by Wheel Horse to eliminate competition within
the company itself. Reo was ended in 1964.

Continental Engines

The Continental 30° bank 1-cylinder engine was a strong
power-plant. A friend of mine has over 50 variations of this
interesting engine. The engine started production in 1946 and even
with all the variations has remained relatively unchanged
throughout the years. The three major changes are as follows:

The first series of engines, the AA Series, had the carb and the
intake mounted underneath the cylinder (updraft intake) and had a
remote fuel tank (the gas was delivered to the carb with a copper
tube from the tank). This series was built from 1946 to 1949-50. It
was sold as a general power plant.

The second series, the AC Series, was basically the same as the
AA with the exception being that siphon feed carb (with fuel tank
directly attached), similar to the ones used on the B&S cast
iron engines, was used. The AC Series was built from 1950 to 1955,
and was only used on lawnmowers.

The third series, the AU Series, was entirely reworked, although
the basic design was unchanged. The carb and intake were now
located on top of the cylinder (downdraft intake) and like the
early engines, had a separate fuel tank. This series was built from
1955-56 until the late ’60’s. All models, with the
exception of the AC Series, were used on any powered equipment you
could imagine (fans, tillers, pumps, generators, David Bradley
tractors, etc.)

As an interesting side note, I used to own an AU Series
Continental mounted in a scale Midget Racer. It had plenty of power
and speed, but the previous owner had found a unique way to
radically increase power without major work on the engine’s
internals. On the dash were mounted two switches, one marked
‘boost’, the other ‘kill’. If you were just riding
around the track and you turned on the ‘boost’ switch, more
often than not the engine would just backfire and die. However, if
you were running at full speed and power, and then threw the
switch, it would feel like someone turned on the afterburners! The
machine would literally spin its tires and gain approximately
another 20 mph at top end. I did not see anything that contacted
the engine in the cart except for an extra wire to the points
cover.

Well, I got curious and removed the engine from the cart to find
out what gave it that radical push at high speed. I mounted the
engine on my ‘test bench’ (my mom’s picnic table) with
two seat clamps I borrowed from my dad. On examination I found that
the ‘boost’ switch actually eliminated the point from the
ignition circuit, leaving a crude but effective capacitive
discharge type of spark control (see diagrams A and B). In a bench
test I made, (NOT recommended), at full throttle the engine would
make a little over 4,000 rpms before the wires fell off of the
switch I had on the table. I didn’t repeat the test because of
two reasons: 1)I was afraid I’d blow the engine up, and 2) my
mom came out of the house to see what the engine was screaming
about and was very displeased with my choice of a work bench (
‘No I don’t want to hear it go faster!’). It was an
interesting project checking that one out. At a later date I did a
similar test on another Continental that was in poor mechanical
shape; it did explode literally. I don’t think it revved any
faster, but it blew pieces of metal over the roof of my garage, not
to mention the mess it made of my ‘test bench’. (You
guessed it. It cost me 89 hard-earned dollars to replace the picnic
bench.)

Continental Motors was acquired by the Detroit Engine Co. in
approximately 1967-78. I believe that the same 30° bank cylinder
engine is still being made under the Deco label; however, I
don’t know if parts are still available.

Special thanks to Jeff Holz for the Continental information.

The third article addresses the question from C. Rennie Waugh,
5705 Goleta Road, Goleta, C A 93117: ‘ We have an Associated 2
HP engine, s/n 344256 and are trying to determine when it was
built. No one out here seems to know.’

SERIAL NUMBER LIST-ASSOCIATED &. UNITED
                      
  4 & 5 Digit S/N
Legend: A=Associated Engine, U=United Engine
  -=information not available  

Serial #

Make

Year

HP

1121*

A

1911

2?

*Early Hired Man with unusual ID plate patented Jan. 3,
1911.

20447

A

1914

?

23313

A

1914

1?

23584

A

1914-15

1?

23782

U

1915

25325

A

1915

?

30217

A

1915

1?

32860

A

1916

1?

37030

U

1917

__

37289

A

1917

?

52079

U

1916

1?

58125

U

1917

3?

80886

U

1915

1?

81502

U

1912

1?

81790

U

1915-16

1?

83291

A

1917

2

For the last three years I have been conducting a serial number
and date search on the Associated-United engines, built in Iowa.
This is being done through ads in GEM, letters and post cards sent
in the mails, and by going to local shows and recording the needed
information directly from the owners. I have found three points of
interest in this project. They are:

1) An Associated engine Experimental, with a unique magneto and
gear setup (approximately 1915).

2) An Associated engine with a 4 digit serial number (1911).

3) An Associated engine with a 7 digit serial number
(1909).(This engine appears to be one made at the start of
Associated production. There is no mistake on the serial numbers,
as I got the information directly off the engines myself.)

If anyone has any more serial numbers or odd information on the
Associated-United Engines, please contact me so I can update the
list.

On a general note it can be said that an engine with a 5 digit
serial number was built before 1918, and the 6 digit engines appear
not to have been built before 1914, as of my present information.
This list does not cover the Colt Series engines.

SERIAL NUMBER LIST-ASSOCIATED & UNITED
           
6 & 7 Digit S/N
Legend: A=Associated Engine, U=United Engine
=information Not Available TG=Throttle Governed

Serial #

Make

Year

HP

103079

U

1913-14

1?

113445

A

1914

1?

117848

U

1914

2

117925

A

1914

2?

131067

A

1915

2?

133166

A

1917

2?

135873

A

1917

2?

137213

A

1916

2?

143575

A

1916

1?

144744

A

1917

2

151328

_

1917

2?

159412

A

1917

2

165017

A

1918

2?

201175*

U

1926

2?

201826*

U

1926

2?

201853*

U

1926

2?

*These engines were located within 2 miles of each
other by different owners in South hamtom, Mass.!

202539TG

U

1926

2?

202672

U

1926

2?

203204

u

1918

2?

203271

u

1918

2?

205184

u

1919

2?

205204

u

1919

2?

206380

A

1920

2?

250388

1915

1?

257067

A

1915

1?

257867

A

1915

1?

258596

A

1915

1?

259146

A

1915

1?

312370

A

__

1?

316784

A

__

1?

321047

A

1919

1?

323808

A

1920

1?

328508*

A

1915

1?

*Experimental Mag gear setup from factory  

332585

A

1920

1?

332840

A

1920

1?

334415

A

1920

1?

337007

A

1921

1?

340886

A

__

1?

342370

A

1920

1?

342529

A

1920

2

344256

A

1921

__

357067

A

__

1?

401405 TG

U

__

4?

509829

U

__

3

510547

A

__

3

605685

A

__

6

610760 TG

A

1920-21

6

801088

A

1918

8

3316784*

1909

*This engine was on display I at a show in upstate New
York (note 7 digit s/n).  

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