LAUSON ENGINES AND TRACTORS

Their History and Development

Lauson Engine

Fig. 1

Content Tools

P.O. Box 518 Painted Post, New York 14870-0518

Introduction

The year 1995 marked the one-hundredth anniversary of Lauson engines. This article will chronicle that history; a manufacturing story that is rich with diversity and change. I first wrote this article in 1974; it appeared in the March/April 1975 edition of The Gas Engine Magazine. Since then, I have obtained much more information enough to warrant a complete rewrite of that original article. Unfortunately Lauson production records dating from before 1956 are believed to have been destroyed sometime around that time, thus precise dating of the earlier Lauson engines is not possible.

THE BEGINNINGS

In 1848 groups of immigrants left Schleswig-Holstein in what was then Denmark and sailed for America. These immigrants carefully selected a location in the New World which has a latitude corresponding to a location in northern Italy, thinking that the climate would be just as favorable. With that expectation, they built their homes with the south side open to the sun. During the winter of 1848-49 they suffered many hardships, but stayed on to form the community now known as New Holstein, Wisconsin.

In the years that followed, the Lauson family, or families, joined the new community, and in 1867 the Lauson Brothers Implement Company was organized, having H. A. Lauson as general manager, C. P. Lauson overseeing machine repairs, and D. H. Lauson as office bookkeeper.

On January 20, 1868 John Lauson was born to Detlaff Lauson. When he was only 14 years old he joined the business with his uncles, after his father died. In 1884, at age 16, John, in full partnership with his uncle George and J. H. Optenburg, opened a new machine repair shop. This shop was destroyed by fire in 1885.

Immediately after the fire John Lauson and J. H. Optenburg organized a new firm and built a new shop. This firm was named John Lauson and H. Optenburg and Company. They specialized in the repair of steam traction engines and also built boilers, tanks, smoke stacks and related items. This firm is believed to have built and sold some 25 complete steam traction engines under the name 'Uncle Sam.'

Sometime between 1887 and 1891 John Lauson bought out Mr. Optenburg's interest in the company (various accounts place the date as either 1887 or 1891) and stopped the manufacture of traction engines. The firm continued to perform boiler work, began production of sheet metal items, and offered general heavy machinery repair work.

By 1895 John's brother Henry had joined the company, which had become the John Lauson Manufacturing Company. Henry Lauson had been working for a gasoline engine builder in Chicago and had some ideas on how a gasoline engine should be built. N. H. Edens was hired at this time and he too was interested in building a gasoline engine. Soon after, plans were laid for the first Lauson internal combustion engine. Robert Hippe was also working for Lauson at that time; he later moved to Chilton, Wisconsin, and built the Hippe-Steiner engines.

The company became incorporated as the John Lauson Manufacturing Company with John Lauson, president; Jacob Schmidt, vice president; and Henry Lauson, secretary and treasurer.

It is believed that the first Lauson engine was built in 1895. This first engine was a four horsepower, four cycle, horizontal cylinder, tank cooled model using hot tube ignition. The engine weighed 1,140 pounds. As seen in a much later photograph (Fig. 1) the valve train is of the 'F-head' arrangement and the engine appears to have had a ported cylinder with a common passage between the exhaust valve and exhaust port location. The engine also appears to have a vertical fly ball governor.

The castings for the first engine were purchased from outside suppliers, and work on the engine progressed slowly. When the engine was completed all of the plant workers were present for the starting ceremony. Henry Lauson was in charge of the start-up and after the engine was running the cheers of the workers were louder than the sound of the engine's exhaust. John Lauson yelled 'belt her up!' and the workmen connected the engine to the plant line-shafts. This first Lauson entered service powering the tooling to produce more engines.

Full serial production of engines probably began around 1898. The first production model featured an eight-inch bore by ten-inch stroke and electric ignition.

In the fall of 1904 the John Lauson Manufacturing Company introduced its first hopper cooled horizontal cylinder engine, a five horsepower size. Following the introduction of this engine the John Lauson Manufacturing Company claimed to be the originator of the hopper cooled design. This engine was given the trade name Frost King because it was designed to be easy to start in cold weather and, to a lesser extent, because the cooling weather could be made non-freezing by the addition of calcium chloride to the water in the hopper. The Frost King design became a big seller and soon thereafter, all sizes of Lauson engines became available in the hopper cooled style.

By 1907 the demand for Lauson engines was so great that a larger factory was necessary. The city of Plymouth, Wisconsin, made efforts to get the company to locate there, even offering a five year tax-free site. But the people of New Holstein would not stand by and let 'their factory' move out of town. They subscribed to all available preferred stock and A. A. Laun, Sr. presented land to the company on which a new factory was built in 1908. This new building was 100 feet wide and 300 feet long and still exists today as the 'core' of the present day factory facility.

Through 1913, all Lauson castings were purchased from out of town suppliers. In 1913 a group of businessmen decided that New Holstein should have a foundry business so the Lauson brothers, along with A. A. Laun, Sr. brought expert foundry man Edward Alyward to New Holstein. The Alyward Foundry Company was formed and a foundry was built on land north of the Lauson factory. This foundry entered production within the year and made all Lauson castings as well as castings for other companies. In 1915, this foundry was purchased by the John Lauson Manufacturing Company.

The Lauson engine line prospered and the company continued to grow. In 1915, the company began to build complete farm tractors.

On April 20, 1922, John Lauson died, following a brief illness.

In 1929, the Lauson family lost control of the company when members of the Lauson Corporation bought out the family's financial interests.

Operating as The Lauson Corporation, the company continued to produce engines and tractors. New air cooled and water cooled engine models were introduced. Unfortunately, severe crop failures in the Plains states caused many farmers to default on payments for Lauson tractors; this dealt a crippling financial blow to the company and brought an end to tractor production.

The Lauson Corporation was sold on May 15, 1935 to the Marshall & Illsley Bank (of Milwaukee, Wisconsin) and The People's Bank of New Holstein. The company was reorganized as The Lauson Company.

The Lauson Company prospered but the company leaders recognized that new sources of capital were needed to foster continued growth. The decision was made to sell the company, with the stipulation that the buyer could not move the company from New Holstein.

In June 1941, the Hart-Carter Company of Peoria, Illinois, purchased The Lauson Company.

In 1955, Tecumseh Products Company, of Tecumseh, Michigan, made an offer to purchase the Lauson plant and in December 1955 the sale was completed. The Lauson line was comprised entirely of four cycle engine models; to complement these with two cycle models, Tecumseh purchased Power Products Corporation, of Grafton, Wisconsin, in 1957.

To this day, production of Tecumseh engines continues in the original Lauson factory.

THE ENGINES

The chronology of Lauson engines is best presented by describing the models shown in various catalogs.

Catalog 13 dates from approximately 1908/1909. By this time the design of the Lauson engine had evolved into the form that would be followed (though not without changes) until production of the horizontal cylinder engines ceased many years later. See figures 2 and 3.

The basic arrangement is the typical four cycle, open crankcase, horizontal cylinder, horizontal crankshaft build, having double six-spoke flywheels. The front end (crank end) of the frame between the main bearing webs is open; a crank guard or splash shield is not shown. One of the features that was promoted in this (and subsequent) Lauson catalogs was that the flywheels on these engines were balanced to a high degree of precision with the result being a very smooth running engine.

The catalog describes the following models:

MODEL

HP

RPM

AA

2.5

400-450

A

4

350-400

B

5

325-350

C

6

300-325

D

8

275-300

DE

10

275-300

E

12

275-300

F

15

250-275

G

20

250-275

The 2.5-12 HP models were available as Frost King hopper cooled engines, while plain cylinder versions were furnished in the 6-20 HP models. The 6-20 HP models employed separate castings for the cylinder and engine frame (and sub-base, when used) but the 2.5, 4 and 5 HP models used a one-piece cylinder/frame/case casting.

Valve location: Both valves in the cylinder head. Atmospheric-operation intake valve, pushrod operated exhaust valve.

Ignition: Battery and coil for all models. 2.5-5 HP were equipped with jump spark (spark plug). A make-and-break ignitor was standard on the 6-20 HP models. A friction drive 'auto sparker' was available.

Camshaft: One of the 'hallmark' Lauson features is that the camshaft on the ignitor-equipped models was constructed with separate cams for the exhaust valve pushrod and the ignitor pushrod. The camshaft runs in an enclosed housing that is partially filled with oil.

Governor: Hit and miss; governor weights located at the magneto side flywheel hub. The 2.5-5 HP models used a single weight.

Fuel: Gas, Gasoline, Distillate, Benzene.

Crankshafts: Machined from a one piece steel billet forging.

Connecting Rods: Turned from a steel forging, with adjustable 'boxes' at each end.

Pulley: Solid pulley was standard, clutch pulley was optional. The actuator on the clutch pulley was a single push-pull lever.

All models were available either as semi-portable (skid mounted), portable (on factory-equipped trucks) or stationary. The plain cylinder models were furnished with a screen cooler and water circulating pump.

Portable saw rigs were available in sizes of 6, 8, 10 and 12 HP. Sleigh runners could be ordered for any of the portable models.

Catalog 13 also shows a vertical cylinder engine, built in sizes of 2, 2.5 and 4 HP. I do not believe that this engine was actually manufactured by the John Lauson Manufacturing Company. This engine appears to be identical to a vertical engine that was sold by the C. P &.

J. Lauson Company of Milwaukee, Wisconsin; in fact, either engine bears a strong resemblance to a Bates and Edmonds vertical engine.

During the early part of this century, several engine building companies having 'Lauson' in their names evolved but there is no known connection between any of these and the John Lauson Manufacturing Company.

Catalog 14 dates from approximately 1910/1911. This catalog describes the following models:

MODEL

HP

RPM

Z

1

500-550

AA

2.5

450-500

A

4

400-450

B

5

350-400

C

6

300-325

D

8

300-325

DE

10

300-325

E

12

275-300

F

15

275-285

G

20

275-285

H

25

275-285

Two-

  

cylinder >25

unspecified

Generally, the single cylinder models are similar to those shown in catalog 13 but, in addition to the new models, certain mechanical changes are apparent.

All models were available as stationary or semi-portable engines and the 2.5-25 HP models were available as portable engines. All of the single cylinder models were available as hopper cooled engines while screen cooled or tank cooled models above 2.5 HP were available.

The optional clutch pulleys shown have a push-pull hand wheel actuator instead of the earlier lever actuator.

All models featured poured babbitt main bearings. Round connecting rods and billet-turned crankshafts were now used only on the 6 HP and larger models; the connecting rods featured a brass babbitt lined box on either end. The 5 HP and smaller models now used a drop forged steel I-beam connecting rod having a poured babbitt big end bearing and a bronze bushing at the small end along with a drop forged steel crankshaft. The 5 HP and smaller models continued to use a one-piece cylinder/frame/base casting. The 6 HP and larger models use the enclosed cambox. The 2.5-5 HP ignitor equipped models use an eccentric, inboard of the cam lobe, to drive the ignitor pushrod.

The ignitor system on the 1 HP model was jump spark, but all other models were available with either jump spark or make-and-break ignition. The friction drive 'auto sparker' continued to be an option.

Catalog 14 illustrates a different type of gasoline mixer (carburetor) than is shown in Catalog 13. On November 10, 1908 the company received a patent for a new gasoline mixer (this date is on the mixer). This is an air valve type of mixer, with an adjustable air bypass passage around the air valve. With this type of mixer a poppet valve is located in the main throat and a gasoline passage communicates to a hole in the valve seat. On the intake stroke, the air valve is lifted from the seat and the resulting air pressure drop across the valve allows gasoline to spray from the hole and mix with the air stream. A needle valve is used for air/fuel ratio adjustment. A variation of this mixer was available for use with gaseous fuels. This style of mixer was used until approximately 1916. See figures 4 and 5 for views of this mixer.

Portable saw rigs were shown, although the available sizes are not listed.

The two cylinder model, of greater than 25 HP, is described briefly on one page, which indicates that technical details were available in a 'Bulletin C.' The basic arrangement of these engines is that of plain jacket horizontally opposed cylinders, double flywheels and a 'flat' double throw crankshaft. A throttling governor was standard equipment; fuel was gas or gasoline. An air starting system and air compressor were furnished with the engines.'

Transition Engines

The 1916 catalog indicates that the low tension gear-driven Sumpter rotary magneto had been adopted four years earlier, which would have been 1912. An uprating of certain models took place around 1912, as evidenced by one engine in the author's collection. This model B engine is rated as '6 horsepower/size 5' and is constructed like the earlier 5 HP model having the one-piece cylinder/frame/base casting. A round connecting rod, typical of 6 HP and larger models, is used. The engine is equipped with a Sumpter magneto and make-and-break ignitor. Like earlier 2.5-5 HP models, the ignitor pushrod is operated by an eccentric on the camshaft inboard of the exhaust cam lobe. The eccentric and cam lobe are not enclosed in the cam box. This engine has the open front frame casting with a sheet metal splash shield. I have also seen smaller transition Lausons built with the one-piece cylinder/frame/base casting and equipped with the Sumpter magneto.

By 1914, the engine frame on all models (2 HP and above), had been redesigned to close the front end 'between the main bearing saddles. A rounded wall was added to this region of the casting and a similarly shaped full length cast iron crank guard was located over the connecting rod and crank throw. At some point separate castings for the cylinder, frame and base were adopted on the smaller models; that was probably done at the same time.

Sales Brochure: Probably printed in 1913, lists the following models:

MODEL

HP

RPM

Z

1.5

550-575

ZA

2

450-500

AB

3

450-500

AC

4.5

400-425

BC

6

350-375

CD

8

315-335

D

10

315-335

DE

12

315-335

E

14

275-300

F

18

275-300

G

22

275-285

H

28

275-285

The engines shown in this brochure have the cast-rounded frame and crank-guard, Sumpter magneto and 1908-pat-ent mixer. The smaller sizes now have an enclosed cam box. All of the models shown have hit and miss governing; the governor arm is now equipped with a speed changing screw. Portable, semi-portable and stationary types were available.

Another innovation, which had previously been used only on 6 HP and higher models, was the ability to start the engine (after drawing in an air/fuel charge) by retarding the spark timing and rocking the flywheels against compression in the opposite direction of normal crankshaft rotation. The timing retard was accomplished by shifting an eccentric pin in the ignitor pushrod train.

Alpha Engines catalog C 8-13: By 1914 the John Lauson Manufacturing Company was producing engines for the DeLaval Dairy Supply Company. Engines sold by DeLaval were sold under the Alpha trade name. Nearly all of the Alpha engines sold are actually Lauson engines. This particular catalog carries a 1913 copyright date; the catalog number may be a print date, which would make this a 1914 catalog. The following models are listed:

MODEL

HP

RPM

ZA

2

450-500

AB

3

450-500

AC

4.5

425-550

BC

6

350-375

CD

8

315-335

DD

10

315-335

EE

12

315-335

EF

14

275-300

FG

18

275-300

GH

22

275-285

HI

28

275-285

This catalog introduces kerosene burning versions of the various engine models. The kerosene versions feature a different cylinder head having a throttling governor carburetor mounted above the cylinder head. On the hit and miss versions the mixer is mounted (as with previous models) beneath the cylinder head. Water injection, a heated air intake and a gasoline starting circuit were also features of the kerosene versions. The throttling governor engines were available with extra-heavy flywheels, intended for electric generator driver service. The gas and gasoline fueled versions continued to use the 1908 patent mixer.

All of the models shown in catalog C 8-13 feature separate castings for the cylinder, engine frame and (when used) sub-base. The frame and crank guards are the round cast front construction described previously. All models continued to use the enclosed cambox; some illustrations in this catalog show the Sumpter magneto mounted on an adapter plate above the cambox, while others illustrate a new cambox top with a cast-in magneto mounting surface.

The connecting rod used on the 2,3 and 4.5 HP models is of drop forged steel I-beam construction; the crankshaft is also drop forged steel. On the 6 HP and larger models the crankshaft and round connecting rod continue to be turned from a forged steel billet.

All models were offered in portable, semi-portable and stationary versions. Plain cylinder portable models were furnished with a screen cooler and all plain cylinder models of 8 HP and higher were supplied with a water circulating pump.

All models were available with either a solid or clutch pulley. Saw rigs of up to 12 HP were available.

This catalog also provides an illustration of a multi-cylinder model having in-line vertical cylinders built in two and four cylinder units rated as 18, 25, 36, 50, 80 and 100 HP. The text indicates that complete details were available in a separate catalog.

Catalog 18: is dated 1916. The engine line is essentially the same as shown in catalog C 8-13, but with three new additions. Also, the ZA now carried a 2.5 HP rating and the AB now carried a 3.5 HP rating.

Two of the new models were a 40 HP and a 50 HP single cylinder (horizontal), kerosene burning stationary engine rated at 235 rpm. These models were available only in plain cylinder versions. A Madison-Kipp force feed lubricator, feeding the main bearings, crank pin and cylinder, was standard equipment. The throttling governor carburetor was mounted above the cylinder head and the general construction of these models was in accordance with the smaller Lauson models.

The other new model was the 1.5 HP Frost King Junior (Fig. 6).

This hopper cooled engine was rated at 450 rpm. Although this model resembles its larger relatives, it has a number of differences: the cylinder head is not water cooled, the ignitor and exhaust valve are operated by a common pushrod with an open dual-lift cam (one lobe performs both functions) actuating the pushrod, the governor weights are mounted in the camshaft gear, and the front of the frame casting is not cast-closed between the main bearing webs. A hinged cranking handle was installed in the ignitor side flywheel. The Junior was equipped with a Sumpter magneto and was sold only in a gasoline version. Many Frost King juniors were sold under the Alpha name.

The kerosene versions of the models shown in this catalog continued to use the throttling governor carburetor located above the cylinder head while the gasoline versions were now equipped with a venturi-type mixer located, as always, beneath the cylinder head. The venturi resembles a boost venturi in a modern gasoline carburetor because some of the airflow through the mixer passes around the outside of the venturi. The gasoline mixes with the air stream passing through the venturi. With the introduction of this mixer (Fig 7), the air valve gasoline mixer was no longer used. This mixer could also be used with distillate and alcohol fuels. The catalog also indicated that a mixer designed for use with gaseous fuels was available.

Hopper cooled gas and gasoline versions covered the range of 2.5-28 HP, while hopper cooled kerosene versions were available from 3.5-28 HP. Plain cylinder gas and gasoline versions covered the range of 2.5-28 HP, while the plain cylinder kerosene versions ranged from 3.5-50 HP.

A force feed lubricator was an option for all versions of the 2.5-28 HP models.

A friction clutch pulley was now furnished as standard equipment on all portable and semi-portable engines above 4.5 HP.

All of the single cylinder models except the Junior, 40 HP and 50 HP were available as portable, semi-portable and stationary engines. The Frost King Junior was available only in portable and semi-portable versions. Plain cylinder portable engines were furnished with a screen cooler. Portable saw rigs, using Frost King engine models, were available in sizes from 4.5-12 HP.

Also described are 'Special Electric' stationary engines. These engines, which are another variation of the basic plain cylinder models, were equipped with extra-heavy flywheels and a gasoline type throttle governing carburetor located beneath the cylinder head. These engines were intended for driving electric generators. Many Lauson Special Electric engines were sold as the driver on Edison Company electric lighting plants.

The multi-cylinder engine, with an illustration identical to the one used in catalog C 8-13, is also shown in this catalog. At this time these engines were produced in four cylinder models, with ratings of 35, 50, and 60 HP at 450 rpm and 80 and 100 HP at 300 rpm. These engines were designed to operate primarily on kerosene (with gasoline starting) although the description also references gas, distillate, motor spirits and alcohol fuels.

The general construction of these engines featured individual cylinders and cylinder heads, an enclosed crank-case with five main bearings and one outboard bearing. Both valves were mechanically operated. The main bearing and cylinder lubrication was by force feed, with splash oiling being used for the crankpins. A throttling governor was used, with a separate carburetor for each cylinder. The ignition system consisted of a single low tension Sumpter magneto and an ignitor at each cylinder. A brass bus bar was used to take voltage from the magneto to the ignitors.

Air starting was standard equipment on the 80 HP and 100 HP versions and included a 1.5 HP engine, air compressor and air tank. The smaller versions used a 'hand starter' but air starting was an option.

Late Teens and Early Twenties: As shown in Bulletin 265 B, dated 11-15-17, the throttling governor kerosene carburetor had undergone a redesign and was now mounted beneath the cylinder head. The venturi type gasoline mixer was still in use so now one cylinder head could be used for either fuel. A gas mixer was also available. The under-head kerosene carburetor retained provision for gasoline starting, water injection and heating of the intake air.

Around this time, the model ZA was uprated to 3 HP, the model AC was uprated to 5 HP and the model BC was uprated to 7 HP.

Bulletin 260, dated 10-1-19, shows that the Frost King Junior had been uprated to 1.75 HP at 475 rpm.

An instruction manual, dating from approximately 1920, lists the engine lineup as covering a range of 1.75 HP to 18 HP in plain cylinder and hopper cooled versions; gas, gasoline and kerosene. Stationary, semi-portable, portable and Special Electric engines are mentioned.

All AB 3.5 HP engines built during 1923, and after, were not equipped to start by turning back against compression.

By approximately 1924, the model AC had been uprated to 6 HP and the model BC had been uprated to 8 HP. Somewhere around this time these two models began to be built with an I-beam connecting rod.

The latest Frost King Juniors, built up to approximately 1924, carried a 2 HP nameplate rating.

A New Era

In 1924 the John Lauson Manufacturing Company introduced its now well known W-series disc-flywheel engines in three models. A brief article in a 1924 edition of Farm Machinery and Hardware Magazine indicates that deliveries of the 1.5 model W began shortly before deliveries of the 2.5 HP model WA and 3.5 HP WB. (Production of the model W may have begun in 1923.) The DeLaval Dairy Supply Company also sold the W-series models under the Alpha name. The W-series engines would remain popular through the 1930s, even as new more-modern models were being introduced. Some of the first model W engines left the factory bearing a Frost King Junior nameplate. I have seen one such engine and the nameplate appeared to have been original because the serial number had the letter W stamped ahead of it.

1924 Catalog: (date unconfirmed). This catalog places special emphasis on the new W-series engines (Fig. 9).

The model W was rated at 525 rpm, while the WA and WB were rated at 450-475 rpm. The W-series engines were built using a single cylinder and frame casting. A sheet metal splash guard was attached at the two front main bearing cap bolts. The crankshaft and connecting rod were made from drop forged steel. The main bearings and connecting rod big end featured removable die-cast babbitt bearing shells. The cylinder head on the W is air cooled, while the WA and WB use a water cooled cylinder head.

Ignition on the W-series models was by make-and-break ignitor; the buyer had a choice of either battery ignition or a Splitdorf F-16 rotary magneto. The magneto was installed inboard of the pulley-side flywheel and was gear driven directly from the crankshaft.

The W-series engines use a single radial-movement governor weight located in the ignitor side flywheel. The governor weight moves a cam collar which, in turn, moves the governor linkage. A hit and miss governor was standard while throttling governor versions were available. A hinged cranking handle was installed on the ignitor side flywheel.

The camshaft is supported on either side of the cam. The single dual-lift cam moves the pushrod to actuate the ignitor, followed by the exhaust valve. The camlobe and follower are not enclosed. Both valves are located in the cylinder head; and atmospheric-operation intake valve was used.

The cylinder drip oiler used on the W-series engines features a metal reservoir with a sliding 'fill door' on top. The needle valve has to be seated to shut off the oiler. These lubricators are similar to ones sold with some Fairbanks-Morse Z engines; the needle valve adjusting knob on the Lauson lubricators has a ribbed edge while the adjusting knob on the Fairbanks-Morse has a scalloped edge. The lubricator components were made, at various times, from either brass or steel.

The W-series engines were available in gas, gasoline and throttling governor kerosene versions. A solid pulley was standard equipment; friction clutch pulley was an option.

This particular catalog shows that the W was available in semi-portable and portable versions while the WA and WB were available in stationary, portable and semi-portable versions. The stationary versions used a separate sub-base.

The model WB engine was also available in a plain cylinder version.

Spoke flywheel engines continued to be available in the 6 HP (AC/450 rpm), 8 HP (BC/375 rpm), 12 HP (DD/350 rpm), 14 HP (EE/275-285 rpm) and 18 HP (FG/275-285 rpm) models and were available in gas, gasoline and kerosene versions. The venturi type gasoline mixer and under head throttling governor kerosene carburetor continued to be used. Plain cylinder and hopper cooled versions were available in the stationary, semi-portable, portable and Special Electric variations.

The Madison-Kipp force feed lubricator continued to be an option. These spoke flywheel models were furnished with a solid pulley as standard equipment and the friction clutch pulley as an option.

This catalog also indicates that saw rigs were available in sizes of 3.5, 6, 8 and 12 HP.

W-Series Evolution: The W-series models continued to evolve almost from the beginning of their production. The original model W was constructed with the gasoline mixer built into the cylinder head but after serial number 3,065 the engine was built with an external, bolted-on mixer like that used on the WA and WB models.

By November 1925, all of the W-series models were using the Wico EK magneto and jump spark ignition. This change became effective at serial number 40,000. The first Wico EK equipped versions used a magneto mounting bracket that bolted onto the side of the cylinder in place of the ignitor. This bracket incorporated the spark plug threads located over the original ignitor passage. Later, the spark plug location was moved to the cylinder head and an intermediate version of the magneto bracket did not include the spark plug threads. Still later, the cylinder casting was changed to eliminate the ignitor passage; the magneto mounting bracket was now bolted to bosses on the water hopper.

Up to serial number 45,000 the cam-shaft geartrain used straight-cut gear teeth; following this, helical gears were used.

Also by the mid-1920s, the model W had received an increased cylinder bore size and was now rated as 2 HP at 525 rpm. The speed on the WA and WB models had been increased to 500 rpm. The WA and WB received a cast, full length splash shield that was bolted to the front of the engine frame with a hinged mount. The W continued to use the sheet metal splash guard.

1928 Catalog: (date unconfirmed). This catalog seems to be the most comprehensive catalog produced by the John Lauson Manufacturing Company because of the wide variety of engine driven equipment included in the catalog.

This catalog opens with an extensive discussion of the design of the W-series models and points out that the company was now using the HUTTO process for finishing cylinder bores. This appears to be a honing process with the stones held in a rigid head that is stroked the length of the cylinder bore to produce the de-' sired surface finish. The catalog states that the process had been adopted about two years earlier.

Throughout the years the John Lauson Manufacturing Company had offered, along with its engines, various pump jacks and various engine/pump combinations using purchased pumps. This catalog also illustrates these, along with diaphragm pumping units, light-plant outfits, contractor's portable table saw rigs, cement mixers and mortar mixers, all powered by W-series engines. The majority of this equipment was probably purchased from outside suppliers. The cement mixers appear to be identical to Lansing cement mixers; in fact, many Lansing cement mixers were sold with a model W Lauson engine bearing a Lansing nameplate.

The model W was now referred to as a 1.5-2 HP engine. An option on the model W was a battery ignition system using a Ford type of buzz coil. The plain cylinder version of the model WB was not shown.

The 6, 8, 12, 14 and 18 HP spoke flywheel engines as described in the 1924 catalog (including the Special Electric versions) continued to be offered, with one change. The AC (6 HP) and BC (8 HP) models were now equipped with the Wico EK magneto and jump spark ignition. This change had been made by October 1926, as indicated in an instruction manual of that date. (At some point during the production of the Wico EK equipped model AC, the pre-1913 open front style of frame and non-magneto cam-box top returned to production, perhaps as a means to save weight and cost.)

Saw rigs were offered in sizes of 3.5,6 and 8 HP. All engines continued to be offered in gas, gasoline and kerosene versions, with a friction clutch pulley as an option.

This catalog also illustrates four cylinder 'Lauson-Beaver' power unit engines, available in 35 and 45 HP models. The engines were mounted in a stand, with radiator and over-center clutch. They appear to be identical to the Beaver engines used at that time in the Lauson farm tractors.