A Unique Engine from Dad’s Amazing Attic

By Staff
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Close-up of the cylinder head and flyball governor. Hesse’s engine, originally an IHC Model M, is affectionately named “Dad.”
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The back and side view of the Prony brake, which Hesse
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His father created from scratch using a multitude of parts.

Always looking for something different to
build, Dad decided to redesign an old engine. Together, we set some
goals that we wanted to achieve from this project. First, we wanted
it to be throttle-governed and able to run slow so the moving parts
could easily be seen. Second, we wanted to have lots of moving
parts to watch. Lastly, we wanted to work the engine so that you
could see how the governor works, and hear the engine coast and
work under a load, and then coast again. We looked around the barn
for an engine to start with and decided on a 1-1/2 HP IHC Model M
engine that was missing a lot of parts to use as a beginning for
the project.

The first thing we needed was a carburetor that had an idle
adjustment and a load adjustment. Dad disappeared upstairs to the
attic above the shop and after a while came back down with a couple
of updraft carburetors. In order to use one of them, the cylinder
head had to be rotated 180 degrees so the intake was on the bottom
and the exhaust was on top. To do this, the exhaust linkage had to
be modified and the head machined to fit the carburetor.

Next, while I was figuring out how to hook up the original
governor, Dad disappeared up the attic stairs and came back with an
old vertical flyball governor he acquired from somewhere a long
time ago. The idea of the flyball governor spinning around was too
good to pass up. We had to use it. By mounting it on the front of
the engine near the carburetor, the linkage to the throttle would
work better and it gave us a good reason to make a sideshaft to
turn it. We always wanted a sideshaft engine.

Looking at the front of the engine with the head upside down,
the flyball governor in front and the exhaust coming out the top of
the head, it was getting difficult to tell what model engine we
started with. However from the back there was no mistaking the
enclosed crankcase and the hand hole cover. It still looked like an
IHC Model M. Once more Dad returned to the attic and eventually
came back with an automatic oiler and a fuel tank. We mounted them
above the crankcase and hooked up the oiler to lubricate the
camshaft. That’s one less grease cup to fill.

Next, we started to work on the ignition system. We wanted
battery ignition for a reliable spark at slow speeds and some way
to adjust the timing while the engine was running. Once again I
turned around and Dad was gone up the stairs. This time he returned
with a Ford Model A distributor. We ran it with a small chain drive
off the camshaft gear and had a lever to adjust the timing from
slightly before top dead center to almost 90 degrees after TDC. Now
we were almost ready to see if our engine was going to run. We just
needed a spark. I asked Dad if he had a buzz coil upstairs. He
smiled and retreated up the stairs and brought back a very
odd-looking coil. It was round, with the high tension coming out
the top like a newer coil but the primary connections were on the
bottom. “It’s a World War II Army surplus igniter from a
flamethrower,” he said. Well that should give us a good hot spark I
told him.

I connected the wires and cranked it over. The engine almost
started itself; it ran great. We set the governor speed at 200 RPMs
and with the carburetor adjusted the throttle lever brought the
engine down to a nice smooth idle at just under 100 RPMs.

Now we started to think about what we could belt the engine up
to that would put a variable load on it so you could see how the
governor works.

After looking at pump jacks, fans and a few other things we had
around the barns we realized we were going to have to build
something from scratch. Dad had an idea for a version of a Prony
brake. A few more trips to the attic and he had the bench covered
with items that included a belt pulley attachment for a Ford 8N
tractor, a front axle, hub and brake assemble from a front-wheel
drive car, a small gear-reduction box from who knows what and also
pulleys, wheels and levers that just seemed to grow into a never
ending supply. The Prony brake that Dad made would automatically
apply the load by tightening the brake caliper and then releasing
it.

With the brake belted up to our one-of-a-kind “HESSE” engine,
you watch the flyball governor open the throttle and hear the
engine bark under a load and then quiet down until the next time
the brake is applied. Thanks to Dad’s amazing attic we have a
display that is interesting to watch and makes it easy for people
to see how a throttle-governed engine works.

Contact engine enthusiast Kevin Hesse at: 6028 E.?Joy Road, Ann
Arbor, MI 48105; kevin@tri-oxy.com

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