By Staff

Mac Sine, 9025 Phoebe Court, Annan dale, Virginia 22003,
recently wrote to GEM, saying, ‘During 1988, among the many
topics that appeared in the ‘Reflections’ column were
Lauson engines and Dr. Alfred Buchi and Turbocharging. I would like
to make the following comments regarding these subjects.

Lauson engines are represented by the following photographs:
23/5/23 and 23/8/21. I have had a special interest in Lauson
engines of all ages and models from the beginning of my interest in
engines and over the years have managed to compile a fairly
complete collection of Lauson literature spanning from
approximately 1910 through the 1950’s. I also have number of
actual Lausons from the various model groups built through the

Over the years I have had good rapport with people at Tecumseh
Products Company (Lauson’s parent since 1956); as far as anyone
knows, pre-Tecumseh serial number lists or production records no
longer exist. I can provide approximate manufacturing dates by
comparison with some of my dated literature. Key points on the
spoke flywheel models are the model or casting letter(s) along with
the horsepower rating, the ignition sys tem, style of carburetor
and whether or not the engine has a cast full-length crankcase
cover. Key points on the disc flywheel models are the type of
ignition, location of spark plug, type of crankcase cover and type
of teeth on timing gears. All other air and water cooled models are
fairly easy to approximately date.

Another dating clue is how the company name is listed on the
name-plate. Prior to approximately 1932, the name was John Lauson
Manufacturing Company. From about 1932 through 1936 the name was
Lauson Corporation, and from approximately 1936 through 1941 the
name was Lauson Company.

There seems to have been some sort of transitional phase with
some of the earliest high speed air and water cooled models
receiving John Lauson nameplates. Engines produced during
Hart-Carter Company’s ownership of Lauson (1941-1956) still
said Lauson Company on the nameplate and, excluding inboard marine
engines and outboard motors, continued to end model designations
with the letter C. Following Tecumseh’s purchase of the company
and subsequent updating of the product line the ending model letter
was changed to an H.

The March/April 1975 issue of GEM carried my article ‘Lauson
Engines, Their History and Development’, in which I reviewed
Lauson engines produced until Tecumseh’s acquisition of the
company. Since then I have not uncovered any additional information
which would war rant revision of my original ‘guesstimates’
of production dates.

The standard base color of the spoke flywheel models is given as
Brewster Green; this corresponds to a DuPont Dulux code of 24166.
Many of the spoke flywheel models appear in the catalogs with
striping on the engine and skids or cart frames but the color of
the striping is not described. Color of the skids or cart frames is
also not given but I do have one skid set with traces of what
appears to be an original red color. Most of the disc flywheel
models were also painted Brewster Green. Lauson engines produced
for the DeLaval Dairy Supply Company, which were sold under the
Alpha name, were also painted Brewster Green. Disc flywheel engines
produced for the Lansing (cement mixer) Company were painted grey.
I beleive that the VW-series milking machine engines were also
issued in Brewster Green. Color of the other high speed air and
water cooled models was dictated by customer order.

I am certainly willing to correspond with people seeking
information about Lauson engines. I am presently on a job project
in Utah, but my files are home in Virginia (mail is forwarded to
me), so my response time could be lengthy depending on whether I
can answer from memory, or would have to wait to review my

On Dr. Alfred Buchi: Dr. Buchi is best known for his development
of the pulse, or ‘Buchi’ type of exhaust turbocharging

The turbocharging system with which most people are familiar is
the constant pressure system. With this sys tem, all of the
engine’s exhaust ports are connected to a common exhaust
manifold which leads into the turbo-charger exhaust turbine. When
the engine is running the pressure in the manifold and at each
cylinder’s exhaust port is essentially constant.

With the pulse turbocharging system, the exhaust manifolding is
divided among the engine’s cylinders with certain cylinders
sharing certain manifold sections. The sections lead into the
turbocharger exhaust turbine. Generally, each section is limited to
three properly ‘spaced’ cylinders. Cylinder spacing is
deter mined by crankpin angle, number of cylinders and firing
order. A divided exhaust manifold insures that the pressure in the
manifold at each cylinder’s exhaust port is lower than if a
single manifold were used.

As an exhaust pulse travels through the manifold runner a lower
pressure area is formed behind it. This lower pressure area allows
cylinder scavenging (valve overlap period on four-stroke-cycle
engines) as the pressure in the exhaust manifold becomes lower than
inlet manifold pressure. Dividing the exhaust manifold according to
cylinder ‘spacing’ insures that the exhaust pulse leaving a
given cylinder will not interfere with the scavenging of other
cylinders on that section.

Comparing two otherwise identical engines having the same intake
manifold pressure, the pulse turbocharged engine will have a
greater pressure differential across the cylinder during the
scavenging period than the constant pressure turbocharged

The Ingersoll-Rand Engine-Process Compressor Division (now part
of Dresser-Rand Company) was the first engine builder to apply
pulse turbocharging to a spark ignited gas fueled engine with the
introduction, in 1945, of the model KVS. Today, Dresser-Rand offers
four-stroke-cycle gas engines with both types of turbocharging
systems although emphasis is on refining state of the art lean-burn
constant pressure turbo charged engines that develop a more
economical fuel rate than the pulse turbocharged engines.’

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