MODEL REVIEW

3 Edna Terrace New Hartford, W 13413 hitnmiss@juno. com

As a longtime fan of old iron and a student of prime mover
mechanisms, I have come to appreciate the effort that goes into the
design and implementation of scale models of the engines that drove
the industrial revolution. There are a few fine machinists who
create replicas of the old time engines in quantity, and offer the
fruits of their labors for others to purchase and enjoy. The
subject of this article blows them all away (picture 1).

This model is a very nearly exact scale replica of the much
coveted Springfield Type ‘A’ 1 HP engine. It was modeled
after the 1900 vintage engine currently on display at the
Coolspring Power Museum in Coolspring, PA (picture 2). The
Springfield Type ‘A’ is considered the first overhead cam
engine with fuel injection. It features an angled sideshaft to
drive a cross shaft which has cams for the intake valve, exhaust
valve, auxiliary intake valve, ignitor, and fuel injector pump and
valves. The governor also spins on the cross shaft, but is
independent of the shaft, and is driven by a leather belt from the
crankshaft (picture 3).

The engine is mostly cast iron, with cast brass, iron and steel
running gear. It comes complete with brass plumbing, functional
(but unnecessary) brass cooling tank, all mounted on a sealed oak
base (oddly, the original 1 HP Springfields were not offered as
portables). The material and workmanship is better than many
one-off models, yet over 50 of them were made. Each engine has at
least one hour of run time on it before it is shipped. All that is
needed is a bit of gasoline with a little two cycle engine oil to
keep the injector pump happy, a battery, small coil, and you are
ready to go. Coleman fuel is NOT recommended. The engine is fairly
low compression, and is very easy to start. It will run all day on
? tank of gas. For starting, there is an air restrictor that is
placed over the end of the intake. It is not a choke, since it
doesn’t pull fuel through the engine. It just restricts the
air. To start, the fuel shut-off is opened, and the battery and
coil are attached. The fuel line is then bled through the drain
valve. The restrictor is placed in the air intake. The adjustment
that controls the pump stroke is backed off for a richer starting
mixture. A few quick flips, and away she goes! After the engine is
good and warm, the restrictor is removed and the plunger is
adjusted so that the engine runs lean while not missing any fires.
Cooling water is not needed if the engine is run slow and not
loaded. It will run all day and just get a little warm. A
personalized, 29 page, spiral bound instruction book is included,
which covers care and feeding. It also has pointers for those of us
who can’t resist tinkering with our toys, and for the folks who
order the unfinished version. Although the engine is a hit and miss
type, it is not a conventional pick blade arrangement. Not in the
least! Referring to picture 4, on the left of the cross shaft is
the bevel gear for driving. Next is the exhaust valve, which is
pretty conventional. In the middle is the ignitor actuated by a
snap eccentric from the cross shaft. There is a ratchet on the snap
eccentric, as on the original, that prevents destruction of the
ignitor trip in the event of a backfire. The main intake valve is
also fairly conventional, and is just to the right of the cylinder.
The belt driven governor assembly is to the right of that. Next is
an auxiliary intake valve, which is opened when the governor allows
the engine to fire. Above that, on the cross shaft, is a cam to
actuate the fuel pump, and another cam on the same assembly which
throws the pump plunger out of action when the engine overspeeds.
The end of the cross shaft has a snap eccentric for operating the
fuel pump valve.

Fuel is fed to the pump by gravity from the galvanised tank
through the valve to the pump. The pump plunger is timed to inject
a metered quantity of fuel into the intake gooseneck during the
intake stroke. The stroke of the plunger is adjustable to meter the
correct amount of fuel. The plunger is actuated by a cam which acts
on a catch block, which is pivoted and spring loaded. The block
mates to another catch block which actuates the plunger and opens
the auxiliary intake valve. When the engine goes over its rated
speed, the governor moves a cam into position, which pivots the
first catch block such that it no longer engages the second one.
The engine misses until the engine falls to its rated speed. The
governor moves the cam out of the way, the catch catches, and the
engine gets another charge.

Once again, Mr. Grenning has brought us a very unique model. The
only non-scale thing about it is probably the tolerances and level
of finish are much better than scale. It is a bit on the heavy
side. At 140 pounds, it is just slightly too heavy for one person
to carry. The price may also seem high for most folks, but if you
have ever priced a full sized Springfield type ‘A’ of any
HP, you know that this is a bargain!

Picture 5 shows a pair of 2 cylinder Springfields made by Wayne.
They are not a scale model of anything Springfield ever made, but
it is very unusual and interesting to watch. It is available in
very limited quantities. Picture 6 is a preview of his next
project. It is a ¹/₆ scale model of the
Otto-Langen atmospheric engine. This model was produced by Grenning
Models before in ¹/₇ scale, but the new
version is more to scale, with correct pattern flywheel, pulley,
and other mechanisms, as well as a more scale cylinder (the old
cylinder pattern is shown). This model will be available in late
summer. It will sell for $3500, complete with oak base, to hide the
ignition system. Only 25 will be built, and very few are unspoken
for.