The Half T Boat

By Staff
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Gilbert Merry
Courtesy of Gilbert Merry, Route 1, Box 56, Lowden, Washington 99342

290 Appletree Drive, Media, Pennsylvania 19063

I was prompted to send this material in by a query on page 2 of
your May-June issue, from Bernard A. Hines . regarding the Half
Model T engine. You can see from the article that I had first hand
contact with this motor and it may therefore be of interest to
others. -H. Upshur

We have a lot of Model ‘T’ Ford experience and variety
in antique car circles these days, but this may be one that at
least some readers have not heard about. The author has had first
hand experience with this antique, however, in construction, use
and quantity.

Back before the last World War the Chesapeake Bay was, as it is
today, a source of quantities of crabs for northern city markets
such as Philadelphia. Now crabbing was carried out in every manner
ranging from a small row boat tending a half dozen chicken wire
traps in the creek (as did the author) to a fleet of gasoline boats
tending several hundred traps. However, the most common was two men
with a small gasoline boat and perhaps 25 to 50 traps.

Tending crab traps requires a boat which just chugs along at low
speed, stops frequently and starts easily. The cost of a marine
clutch and reverse gear was prohibitive to the small Chesapeake Bay
crabber, so he had to figure on starting and stopping the motor
itself. The motor had also to be a cheap one, with low maintenance
and parts cost; as the crabber was then, even as now, a poor

The Model ‘T’ Ford answered the need once again, since
they were plentiful, cheap, economical to operate and any local
garage, farm store, or Western Auto had parts galore. But the
crabber went Henry one better and used only half the ‘T’
engine, as that provided more than ample power and gave him spare
valves, rods and pistons to boot. The front half was used because
it had the needed timing gears and distributor and the propeller
was coupled to a flange welded on where the fan pulley came off. A
four cylinder Chevrolet flywheel, also plentiful, was bolted to a
flange welded on the other end of the crankshaft, the latter being
cut off to just retain the center main bearing.

Naturally, ‘halving’ the engine began by completely
disassembling it. Block and cylinder head, intake and exhaust
manifolds were then cut off at the proper place by use of many
hacksaw blades and much elbow grease. This was time consuming, but
as these parts were cast iron, it was possible. (I still have
callouses to prove it.) Not so, however, with the crankshaft. These
were burned off with a cutting torch and smoothed up on a grinder
as they are too hard to deal with by hacksaw. The oil pans were
also hacksawed off.

This upright, single flywheel engine is two cycle and is marked
John Deere Plow Co., Portland, Oregon; Spokane, Washington, on the
tag. I feel sure John Deere didn’t make it and would like any
information on who did and if anyone else has one like it.

Now the method of stopping off the various openings left by the
cutting so that the half engine would be water tight, oil tight and
gas tight, was again dependent on the economic means of the
crabber. The better method of course was to make up plates of light
gauge steel, and weld them on water jacket, oil pan, head and
manifolds, but this was by no means necessary except for the
exhaust manifold. Actually, though not previously mentioned, the
half ‘T’ could be used as a one or two cylinder engine, and
in many cases it was used as a one cylinder engine only for the
smaller boats by removing the rod and piston assembly nearest the
flywheel. This was particularly true if the boat installation
required a fair shaft angle and tilt to the engine, as oil would
not stay under the forward cylinder rod anyway. In the one cylinder
Version it was quite feasible to fit blocks of hardwood, whittled
by hand, and driven with a rag around them into the water passages
and intake manifold. A small wooden board with a strip of felt
around it was fitted in the end of the oil pan and held with

The half ‘T’ engine started very easily by stroking over
the flywheel, using ‘hot shots’ to the ‘T’ coils.
It would frequently start when hot just by switching on and
throwing the spark around and could be run on kerosene for long
journeys. Cooling water circulation was invariably by
‘kicker’ pump, merely a pipe elbow under water facing the
propeller slip steam and piped into the engine block. The boat
bottom and bilges were always sloppy with oil and water, but no
hard working crabber ever minded this.

Of course, the whole ‘T’ engine was occasionally found
in a boat, but the large planetary transmission did not lend itself
well to this use and the forward cylinders usually starved for oil.
But the half ‘T’ was a real answer and will live a long
time in my boyhood memories.

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