A Study of Palmer Marine Engines Using Old Catalogs

By Staff
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This old ad was taken from Gasoline Engines Volume 3, a collection of vintage advertising compiled by Alan C. King.

R.R. 2, Box 697, St. Michaels, Maryland 21663

I became interested in Palmer engines while restoring several
for the Chesapeake Bay Maritime Museum in St. Michaels, Maryland.
The museum has some old Palmer catalogs which I examined. Then
Richard A. Day, Jr. loaned me his collection of original Palmer
catalogs. He also furnished me a list of Palmer models written in
the 1950’s by David Stevens, a Palmer employee. It includes the
years the models were built, based on limited company records and
the memory of old-time company employees. Stevens’ list is
incomplete and some of the dates are in error.

Palmer History: In the April 10, 1924 issue of
Motor Boating is a brief account of the beginnings of the Palmer
Bros. Engines, Inc., written by E.E. Palmer, son of Ray Palmer. Ray
and Frank Palmer built telephone equipment in Mianus, Connecticut
beginning in 1887. Their company was The Mianus Electric Company.
Around 1890, they began looking for a small internal combustion
engine to power a pleasure boat on the Mianus River. In 1894 they
still had not found a small engine, so they decided to build one.
This engine had a bore and stroke of 3?x3? was two-cycle, with make
and break ignition. Their greatest problem was the design of the
make and break ‘sparker,’ as existing designs were of long
‘on’ time and slow release. In later years they claimed to
have spent $5000 on development which was a lot of money in those
times. However, with their experience in electricity, they solved
the problem very well.

The Science Museum in London has cut-away engines on display
that are to show the first two-port and three-port engines and they
mention the inventors of each. According to the museum, Joseph Day
of Bath, England obtained patent 6410 on the two-port system, dated
April 14, 1891. I have obtained a copy of that patent, and it does
show the familiar two-port system. Day built marine engines and the
Science Museum has a 1913 model on display. He used hot-tube
ignition on his early engines, though that is not part of the
patent. Ignition timing was not well controlled and his engines had
a tendency to reverse unexpectedly. The three-port invention,
according to the museum, was by Frederic William Cock, also of
Bath, and a Day employee. The patent is 18,513, October 15, 1892.
That patent clearly shows the three-port system. (These patents are
of the period when British patent numbers started with 1 each

Day and Cock obtained U.S. patents in 1895. Day’s two-port
patent is 543,614, dated July 30, 1895, and the application date is
May 21, 1892. Day’s residence was Spring Gardens, Bath. He
stated that he had patents in Britain, numbers 6,410 and 9,247 (the
latter dated June 1, 1891). There is a version in the U.S. patent
office that is from 9,247.

Cock’s U.S. patent is 544,210, dated August 6, 1895 with an
application date March 10, 1894. He stated his British patent is
18,513 of 1892. The patent was assigned to Joseph Day.

American manufacturers, including Palmer Brothers, apparently
did not obtain rights to the Day two-port patent. In an effort to
recover some royalties, Day sold licenses on the three-port patent
to Palmer Bros, and ten other U.S. manufacturers. Day announced
this in a notice placed in Rudder Magazine in 1905. Under U.S.
patent law of the time, the U.S. patent would expire when the
British patent expired. This meant that U.S. manufacturers had to
pay royalties only until October 15, 1906. My thanks to Hugh
Torrens of the University of Keele, Staffordshire, England for some
of these facts.

Now back to Palmer beginnings: By 1896, Palmer Brothers were
building two-port engines in several cylinder sizes. They also
built boats as the best way to sell engines. Early catalogs had
‘Gasoline Engines and Launches’ on the cover. Later, there
were separate catalogs for launches. I do not know just when Palmer
stopped building launches but it was between 1916 and 1924.

That first Palmer engine ran in a launch for 15 years before it
was retired. Later, it was displayed in boat shows labeled
‘Where It All Began.’ It still exists and is owned by
Richard A. Day, Jr.

Model List: The tabulation is my list of models
based on the old catalogs.. I omitted all engines that were
stationary versions of marine engines and all models that were
marine conversions of engines built by Ford, Hercules, Wisconsin,
etc., though I mention the conversions in the text below. In the
right hand column of the list are Stevens’ dates plus my
approximate dates based on the catalog study. I must stress the
word ‘approximate,’ as I did not have a catalog for every
year. Palmer built engines to special order even after they were no
longer listed. Furthermore, there are conflicts between catalog
dates and Palmer advertisements. More research is needed on
introduction and termination dates for Palmer models.

Until about 1960, the last two digits of a Palmer serial number
indicate the year an engine was completed for shipment. After 1960,
the last digit was the year. I have seen casting dates on cylinders
and heads that were later than the nameplate date, but these simply
indicate replacement parts. Nameplate dates that help to refine the
introduction and termination years are needed. Send them to me at
R.R.2, Box 697, St. Michaels, Maryland 21663 or Richard A. Day,
Jr., R.R.2, Box 44, Leonardtown, Maryland 20650.

The Catalogs: The following are my notes from
the catalogs. I tried to describe the essentials of the designs and
note the differences from each previous catalog. Data in the form
4×5 are the bore and stroke in inches.

Before 1900: Palmer Bros., Mian us, Ct.

The cylinder sizes are not listed, but they offered three
engines-1?, 3, and 4 HP. The cylinder and crankcase are one casting
with the main bearings in the separate end covers. The engine
mounting is a pad under the crankcase, like steam engines and
stationary internal combustion engines. Make and break ignition is
used with the stationary electrode through the removable head and
the moving one through the cylinder. The passage between the
crankcase and the intake port is a separate part, with a throttle
in the passage. Three launches are offered. There are testimonial
letters dated 1898 and 1899.

The reader is invited to write for a special catalog of
telephone equipment, so their original business has not been

1902(?): The Palmer Bros, factory is now in Cos
Cob, ConnectionChanges-The engines have been
redesigned with a horizontal split line through the main bearings,
a cast-in mixture passage from the crankcase to the intake port,
and side-arms for mounting. They are now called models B, C, D, and
E of  1?, 3, 5, and 7 HP. Bore and stroke are not listed. The
advantage of the new split line is that the engine could be
disassembled without removing the flywheel.

Additions-More launches are offered. Four cycle
horizontal stationary engines are shown. Most likely Palmer did not
make these engines, but were only sales agents.


Deleted-The horizontal stationary engines.

Additions-Large four cycle marine engines are
offered; the F, G, F4, G5, and K. All are twin cylinder except the
F4 and G5 which are four cylinder; this is not an error as the G5
really was a four cylinder. No cylinder sizes are listed; however,
the F is rated at 8 HP, the G at 12, and the K at 16, so that is
the progression of cylinder sizes. One picture applied to all
three, so they must have been similar in design. See 1907 for a
description of the K.

1907: The cylinder sizes of the B, C, D, and E
are now listed: 3? x 3?, 4? x 4? 5 x 5, 6 x 6.

Deleted-The F, F4, G, G5.

Additions-Three-port engines, the O, P, and Q
were introduced in the spring of 1906, it states. These are jump
spark engines of three different cylinder sizes and are built in
one and two cylinder versions. Bore and stroke are not stated. With
make and break, they are the S, T, and U. These have the 1907
detachable sparker. Also new-the L (4? x 4?) and the M (5 x 6) are
shown as 1,2, and 4 cylinder four cycle engines. They have suction
operated (atmospheric) intake valves, jump spark ignition, exposed
cams and timing gears, and drip oilers as though there is no
lubrication from a sump. A float-type carburetor is used.

Changes-The K is described as a two-cylinder,
four cycle L-head engine, 7?xl0. The detachable sparker is now
used. There is provision to shift the camshaft to aid starting; we
know that this device will be used by Palmer on many future

1908(?): They claim 35,000 satisfied users and
now can assemble engines in batches of 100 of one size. Among the
supplies is listed dark green enamel. This color must have been
used at least through 1908. The pages showing the K engine are
missing.Additions-The R (5 x 6) is shown for the
first time. The cylinder size indicates that the design is based on
the M, which continues in the Palmer catalog. The R is offered in
1, 2, and 4 cylinder models. They have make and break ignition and
a T-head with camshafts on both sides. The cams and gears exposed,
like the L and M.Changes-The K has been redesigned
with a T-head, similar to the R just described. It has exposed cams
and gears and make and break with the detachable sparker. This is a
major redesign of the K without assigning a new model designation.
The L2 and M2 are now available with jump spark.

1910(?): This year there is a gasoline engine
catalog and a separate launch catalog, also in the collection. The
cover designs are matching. The engine catalog has four pages
missing; they probably show the large four cycle engines’. No
changes to the model line-up can be seen, though the B, C, D, and E
have a new-style water pump. There are excellent photos of the
three-port engines. One can examine the multiple drip oilers with a
single reservoir on the two cylinder, three-port models.


Deleted-The B and E two-port engines.

Additions-A three-cylinder R (R3). Also added,
Q3, P3, and O3 designs.Changes-The L2 and L4 now
have a belt-driven mechanical oiler. Enamel is offered in either
green or grey, so the change to grey must have been between 1908
and 1912. The two-cycle engines have no drip oilers, so oil is now
to be mixed with the fuel. (The Palmer Gas Engine Hand Book, 1911
edition, has instructions for mixing oil with the fuel, 1 pint to 5
gallons of gasoline.) The K series is available with either make
and break or jump spark. There is a new 1912 Eccentric Timer which
has a very large roller.

1915: This is a gasoline engine catalog.
Launches may be in a separate catalog.Deleted-The

Additions-The model E is
back.Changes-The R becomes NR (New R) with cams
and gears enclosed. The L series has been redesigned as the NL (New
L) with T-head. There are the NL1, NL2, NL3, and NL4. The NL has
enclosed cams and gears. The NR and NL were announced in a Palmer
advertisement in December, 1921, so they must be in the 1913
catalog. The K has been redesigned with enclosed cams and gears,
becoming the NK2, NK3, and NK4. These also may be in the 1913 or
1914 catalog. High tension geared magnetos are offered.

1916:Deleted-The remaining three-cylinder
three-port engines.

Additions-Palmer offers a kerosene adaptor for
two cycle engines. It is screwed into a tapped hole in the transfer
port so that fuel impinges onto the hot piston baffle. The engine
is started on gasoline, then the gasoline is shut off and the
kerosene adaptor turned on. Oil cannot be mixed with the fuel (drip
oilers must be used). Not mentioned is a ‘hot head’ that
Palmer offered for two-port engines. It had no cooling passage so
is helped to vaporize kerosene. For using kerosene in four cycle
engines they offer a dual-bowl Kingston carburetor. New Engine: The
TM, a four cylinder L-head engine, 2?x3?. It looks like a small
model T Ford engine. Dick Day tells me it was not a Palmer design,
but was purchased. It was not a reliable engine.


Deleted: The S1 and S2. There is no mention of
kerosene adaptors.Additions: The Q3 is back. The
NLS design is added; this is the NL with stroke increased to
6′. There is now an F1

Changes: The NK and F engines are all jump


Deleted: The NLS engines, the O1, O2, and the
O3. The TM is not shown, yet it was in a Palmer advertisement in
December, 1921.

Additions-F6 and NK6 engines are now offered.
The RA1 and RA2 (4?x6) and the RW1 (5? x 6?) variations of the


Deleted-The Q2 The two-port E has been removed

Additions-The VH which is a four cylinder engine with overhead
cam 3 x 4? 14 HP at 1200 rpm, which is quite a high speed for a
Palmer engine. The VH probably is a new model, as it is featured on
the cover. It has electric starting. The TM is back.


Deleted-The three-port engines except for Q1
and Q2.Additions-The YT1 and YT2. The YT (for
Yacht Tender) is a small four cycle engine with push-rod operated
overhead valves. The YT1 had been advertised as beginning in
production in December, 1921. A Palmer advertisement in April 1924
announced the ‘New 1924 YT-2,’ so the YT-2 may not actually
have been produced in 1922. The RW2 and RW4 have been added. The
VHL which is like the VH except for ?’ larger bore (3? x


Deleted – The D and the RW series. The last of
the three-port engines. The model C, a two-port, is the only
two-cycle still shown.

Additions-The ZR, built in 1,2, 3, and 4
cylinder models. This engine is like the NR T-head except that bore
is increased to 5?’ (5?x6) and the engine has been given a
removable cylinder head. Palmer claims decreased combustion chamber
area, increased compression ratio, and higher rated speed. They
point out that the head can be removed without breaking any water
connections. The ZR will prove to be a most successful engine and
the ‘Cadillac of Work Boat Engines.’

The early ZR3 and ZR4 had gear-type coolant pumps. They
sometimes lost prime and were easily fouled by debris, so Palmer
soon reverted to their usual plunger pumps. There also was a
problem with air pockets in the cylinder head, so a change was made
to all ZR engines to discharge coolant from the very top of the
head, then down to the exhaust flange or exhaust manifold. These
variations can help to identify early model ZR’s.


Deleted-All NL engines except the NL1. The
YT2.TheVH.Additions-The PB6 (Play Boy Six) L-head
engine with dual ignition and the exhaust manifold cast in the
cylinder block. Also added was the LH (Little Husky), an L-head
four cylinder with magneto and impulse coupling
standard.Changes-The NR has become the PNR (Palmer
New R)with removable head like the ZR.

1937: For some years, the Palmer catalog was
loose-leaf in a green binder, undated. Such a catalog is not
trustworthy, as pages can be removed without it showing. 1 will
list the models offered in 1937 based on a dated price sheet. Only
the new models are highlighted:

The YT1. The LH or Little Husky, L-head 4 cylinder. The HH or
Half Husky two cylinder. The PAL, L-head 4 cylinder with electric
starting designed in, enclosed flywheel, and dual ignition (PAL
stood for PAlmer-Lycombing). It was their first conversion. The
name was sometimes spelled Pal. The Power Boy 6 (formerly called
Play Boy Six). The SK6 (Storm King Six), a larger L-head six. The
GW6 Green Witch Six. An even larger L-head six, also with dual
ignition. The ZR series. The PNR series. The F series. The NK
series. I have listed the Pal in the table even though it was a
conversion as it was very important during WWII.

Production of the C had ended in 1930. It had remained nearly
unchanged since 1900. The minor changes that were made over the
years were: the design of the lower cylinder, replacement of the
mixing valve by a check valve and a Schebler model D or a Kingston
‘5-ball’ carburetor about 1906, and the new water pump
already mentioned.


Additions-A marine conversion of the Ford Model
A-B engine. I have loose sheets that show a stratified-charge Ford
A-B and a Ford V8 conversion.Changes-The LLH (Big
Husky) is offered in addition to the LH. It has the bore increased
?’. The LLH was actually introduced in 1932 according to


Deleted-The Ford conversion.

Additions-Diesels: the RND4, RND6, and RND1
(the latter a stationary engine).The PH6 which is a marine
conversion of a Hercules engine.

Changes- The SK6, GW4, and GW6 are noted as
‘custom built’ as though none were built for stock.

1947?: Palmer had developed their diesel series
prior to WWII. However, the government gave Palmer the war
assignment of building the PAL engine, for lifeboats, and they
built about 11 per day. They also built a few hundred of the GW-4
and GW-6 for the Navy.

The company had been managed for some years by Carl Hathaway, a
son-in-law of Frank Palmer. He sold the company to Columbia Air
Products in 1945 and they changed the name to Palmer Engine
Company. The company went bankrupt in 1947 and a group of senior
employees bought the company at auction in November 1947.

The post-war catalog is a two-color sheet, undated. The engines
shown are:

The RND6, RND4, diesel marine engines (plus 1, 2, and 3 cylinder
stationary versions of the diesel), the YT1, the ZR models, and the
PH-45, PH-75, and PH-120 which were marine conversions of
International Harvester engines. We know that the YT1 will be
replaced by the BH in 1948 and the BH will be replaced by the PW-27
(a conversion of a Wisconsin engine) in 1957.

Dick Day tells me that Julius Ulrich designed the YT1 and YT2
when he first joined the company. The YT1 was very popular but the
YT2 much less so. All the engines that followed until 1950 were his
work; the BH was his last. BHT, BHW, and BH-25 engines can be
found; these numbers represent minor engineering changes.

Palmer continued with conversions of International Harvester
engines and the one Wisconsin engine. The company closed its doors
for the last time in 1973.


1.  Palmer was one of the earliest and the most successful
of the American builders of two-cycle engines.

2.   They introduced a line of three-port engines in
1906. To please more customers, these engines were built both with
jump spark and make and break.

3.  Beginning in 1912, they converted their four cycle
medium and heavy duty line to T-head. The design may have been
chosen because it was easier to cast. There were several T-head
cars at that time.

4.  1917-1926 was a period when a ridiculous number of
variations of the bore and stroke of the basic NL and NR engines
were produced.

5. The 1930’s was a period when high-speed four and six
cylinder engines were developed, followed by the diesels.

6.  Real engine design ended at Palmer after 1948 with the

Acknowledgement: I am most grateful to Dick
Day, not just for loaning the catalogs, but for his critique of my
early drafts and supplying many interesting bits of information
about the Palmer Brothers and their engines.

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